# Simple Dev Tools — Full Content > This file contains the complete, inlined content of every tool page on Simple Dev Tools — full descriptions and FAQs — so an AI system can answer questions about any tool without crawling further. For a short navigational overview instead, see /llms.txt. Simple Dev Tools is a collection of free, privacy-first developer utilities. Every tool runs entirely client-side in the browser; no data is ever uploaded, logged, or stored on a server. Site: https://simpledevtools.org Tool count: 47 Categories: JSON, Security, Encoding, Text, Generators, AI / LLM, DevOps, API, Design === ## JSON ### JSON Validator URL: https://simpledevtools.org/tools/json-validator Category: JSON Paste JSON to check it's syntactically valid, with precise error locations for anything that's broken. Runs entirely in your browser. FAQ: Q: Is JSON Validator free to use? A: Yes, JSON Validator is completely free with no sign-up, usage limits, or paywall. Q: Does JSON Validator send my data to a server? A: No. JSON Validator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JSON Validator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### JSON to CSV Converter URL: https://simpledevtools.org/tools/json-to-csv Category: JSON Paste a JSON array of objects and instantly get a downloadable, properly-escaped CSV runs entirely client-side, nothing uploaded. FAQ: Q: Is JSON to CSV Converter free to use? A: Yes, JSON to CSV Converter is completely free with no sign-up, usage limits, or paywall. Q: Does JSON to CSV Converter send my data to a server? A: No. JSON to CSV Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JSON to CSV Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### CSV to JSON Converter URL: https://simpledevtools.org/tools/csv-to-json Category: JSON Paste or drop a CSV file and get clean, structured JSON back, with automatic type detection for numbers and booleans. FAQ: Q: Is CSV to JSON Converter free to use? A: Yes, CSV to JSON Converter is completely free with no sign-up, usage limits, or paywall. Q: Does CSV to JSON Converter send my data to a server? A: No. CSV to JSON Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use CSV to JSON Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### JSON to YAML Converter URL: https://simpledevtools.org/tools/json-to-yaml Category: JSON Paste JSON and get a clean, correctly-indented YAML equivalent useful for Kubernetes configs, CI pipelines, and more. FAQ: Q: Is JSON to YAML Converter free to use? A: Yes, JSON to YAML Converter is completely free with no sign-up, usage limits, or paywall. Q: Does JSON to YAML Converter send my data to a server? A: No. JSON to YAML Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JSON to YAML Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### YAML to JSON Converter URL: https://simpledevtools.org/tools/yaml-to-json Category: JSON Paste a YAML file (including multi-document YAML) and get valid JSON back, parsed entirely in your browser. FAQ: Q: Is YAML to JSON Converter free to use? A: Yes, YAML to JSON Converter is completely free with no sign-up, usage limits, or paywall. Q: Does YAML to JSON Converter send my data to a server? A: No. YAML to JSON Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use YAML to JSON Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### JSON Diff Checker URL: https://simpledevtools.org/tools/json-diff Category: JSON Paste two JSON documents side by side to see added, removed, and changed keys highlighted clearly no upload, instant comparison. FAQ: Q: Is JSON Diff Checker free to use? A: Yes, JSON Diff Checker is completely free with no sign-up, usage limits, or paywall. Q: Does JSON Diff Checker send my data to a server? A: No. JSON Diff Checker runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JSON Diff Checker on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. --- ### JSON Minifier URL: https://simpledevtools.org/tools/json-minifier Category: JSON Paste formatted JSON and get a compact, whitespace-free version ideal for reducing payload size before sending over the wire. FAQ: Q: Is JSON Minifier free to use? A: Yes, JSON Minifier is completely free with no sign-up, usage limits, or paywall. Q: Does JSON Minifier send my data to a server? A: No. JSON Minifier runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JSON Minifier on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is there a file size limit? A: There's no hard server-side limit since everything runs in your browser, but very large payloads (tens of MBs) may slow down rendering depending on your device. === ## Security ### JWT Decoder URL: https://simpledevtools.org/tools/jwt-decoder Category: Security Paste a JWT to see its header, payload, and signature broken down into readable JSON. Decoding happens locally; your token never leaves your device. FAQ: Q: Does this tool verify the JWT signature? A: No. It only decodes the header and payload so you can read the claims. Verifying the signature requires the issuer's secret or public key, which this tool never asks for or has access to. Q: Can expired or malformed tokens be decoded? A: Yes, the header and payload will still decode as long as they're valid Base64URL JSON, even if the token itself has expired or fails verification elsewhere. Q: Is JWT Decoder free to use? A: Yes, JWT Decoder is completely free with no sign-up, usage limits, or paywall. Q: Does JWT Decoder send my data to a server? A: No. JWT Decoder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use JWT Decoder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### Password Generator URL: https://simpledevtools.org/tools/password-generator Category: Security Create cryptographically random passwords with configurable length and character sets, generated locally in your browser. FAQ: Q: Are generated passwords stored or logged anywhere? A: No. Passwords are generated locally using your browser's crypto API and are never transmitted or stored closing the tab discards them permanently. Q: Is Password Generator free to use? A: Yes, Password Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Password Generator send my data to a server? A: No. Password Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Password Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### Certificate Decoder URL: https://simpledevtools.org/tools/certificate-decoder Category: Security Paste a PEM-encoded certificate to see its subject, issuer, validity dates, and extensions decoded into readable JSON entirely client-side. FAQ: Q: Is Certificate Decoder free to use? A: Yes, Certificate Decoder is completely free with no sign-up, usage limits, or paywall. Q: Does Certificate Decoder send my data to a server? A: No. Certificate Decoder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Certificate Decoder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### Hash Generator URL: https://simpledevtools.org/tools/hash-generator Category: Security Enter text or upload a file to compute common cryptographic hashes locally in your browser, nothing is uploaded. FAQ: Q: Is MD5 or SHA-1 safe to use for passwords? A: No. MD5 and SHA-1 are considered cryptographically broken for password storage. Use bcrypt or Argon2 for passwords; use SHA-256/512 only for checksums and integrity checks. Q: Is Hash Generator free to use? A: Yes, Hash Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Hash Generator send my data to a server? A: No. Hash Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Hash Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### Bcrypt Hash Generator URL: https://simpledevtools.org/tools/bcrypt-generator Category: Security Enter a plaintext password to generate a bcrypt hash, or verify a password against an existing hash computed locally. FAQ: Q: Is Bcrypt Hash Generator free to use? A: Yes, Bcrypt Hash Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Bcrypt Hash Generator send my data to a server? A: No. Bcrypt Hash Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Bcrypt Hash Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### HMAC Generator URL: https://simpledevtools.org/tools/hmac-generator Category: Security Enter a message and secret key to compute an HMAC signature useful for verifying webhook payloads and signed requests. FAQ: Q: Is HMAC Generator free to use? A: Yes, HMAC Generator is completely free with no sign-up, usage limits, or paywall. Q: Does HMAC Generator send my data to a server? A: No. HMAC Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use HMAC Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### Password Strength Checker URL: https://simpledevtools.org/tools/password-entropy-checker Category: Security Enter a password to see an entropy estimate and practical strength rating, calculated entirely in your browser never sent anywhere. FAQ: Q: Is Password Strength Checker free to use? A: Yes, Password Strength Checker is completely free with no sign-up, usage limits, or paywall. Q: Does Password Strength Checker send my data to a server? A: No. Password Strength Checker runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Password Strength Checker on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. --- ### PEM to DER Converter URL: https://simpledevtools.org/tools/pem-to-der Category: Security Paste a PEM certificate or key to convert it to binary DER format (and back), entirely client-side. FAQ: Q: Is PEM to DER Converter free to use? A: Yes, PEM to DER Converter is completely free with no sign-up, usage limits, or paywall. Q: Does PEM to DER Converter send my data to a server? A: No. PEM to DER Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use PEM to DER Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Is it safe to paste sensitive data into this tool? A: Yes. All security tools on Simple Dev Tools run entirely client-side using your browser's built-in crypto APIs. Nothing is uploaded or logged. === ## Encoding ### Base64 Encoder/Decoder URL: https://simpledevtools.org/tools/base64 Category: Encoding Convert plain text to Base64 or decode existing Base64 back to readable text, entirely client-side. FAQ: Q: Does this support Base64URL encoding? A: Standard Base64 is supported by default; if you need the URL-safe variant (- and _ instead of + and /), convert those characters manually before decoding. Q: Can I encode binary files, not just text? A: This tool is built for text input. For binary files like images, use a dedicated file-to-Base64 converter to avoid corrupting the data. Q: Is Base64 Encoder/Decoder free to use? A: Yes, Base64 Encoder/Decoder is completely free with no sign-up, usage limits, or paywall. Q: Does Base64 Encoder/Decoder send my data to a server? A: No. Base64 Encoder/Decoder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Base64 Encoder/Decoder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### URL Encoder/Decoder URL: https://simpledevtools.org/tools/url-encoder Category: Encoding Safely encode special characters for use in URLs, or decode an already-encoded URL back to plain text. FAQ: Q: Is URL Encoder/Decoder free to use? A: Yes, URL Encoder/Decoder is completely free with no sign-up, usage limits, or paywall. Q: Does URL Encoder/Decoder send my data to a server? A: No. URL Encoder/Decoder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use URL Encoder/Decoder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. === ## Text ### Regex Tester URL: https://simpledevtools.org/tools/regex-tester Category: Text Write a regex pattern and test it against sample text with live match highlighting, capture groups, and flags support all client-side. FAQ: Q: Is Regex Tester free to use? A: Yes, Regex Tester is completely free with no sign-up, usage limits, or paywall. Q: Does Regex Tester send my data to a server? A: No. Regex Tester runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Regex Tester on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Text Diff Checker URL: https://simpledevtools.org/tools/text-diff Category: Text Paste two versions of text or code to see a clear, line-by-line diff highlighting additions and deletions, computed locally. FAQ: Q: Is Text Diff Checker free to use? A: Yes, Text Diff Checker is completely free with no sign-up, usage limits, or paywall. Q: Does Text Diff Checker send my data to a server? A: No. Text Diff Checker runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Text Diff Checker on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Markdown to HTML Converter URL: https://simpledevtools.org/tools/markdown-to-html Category: Text Paste Markdown and get valid, readable HTML output instantly rendered and converted entirely in your browser. FAQ: Q: Is Markdown to HTML Converter free to use? A: Yes, Markdown to HTML Converter is completely free with no sign-up, usage limits, or paywall. Q: Does Markdown to HTML Converter send my data to a server? A: No. Markdown to HTML Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Markdown to HTML Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Case Converter URL: https://simpledevtools.org/tools/case-converter Category: Text Paste text or an identifier and instantly convert it between camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE. FAQ: Q: Is Case Converter free to use? A: Yes, Case Converter is completely free with no sign-up, usage limits, or paywall. Q: Does Case Converter send my data to a server? A: No. Case Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Case Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Word & Character Counter URL: https://simpledevtools.org/tools/word-counter Category: Text Paste any text to see word count, character count, sentence count, and estimated reading time updated live as you type. FAQ: Q: Is Word & Character Counter free to use? A: Yes, Word & Character Counter is completely free with no sign-up, usage limits, or paywall. Q: Does Word & Character Counter send my data to a server? A: No. Word & Character Counter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Word & Character Counter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Slug Generator URL: https://simpledevtools.org/tools/slug-generator Category: Text Paste a title or phrase and get a lowercase, hyphenated, URL-safe slug ready to use in a route or filename. FAQ: Q: Is Slug Generator free to use? A: Yes, Slug Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Slug Generator send my data to a server? A: No. Slug Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Slug Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### HTML Entity Encoder/Decoder URL: https://simpledevtools.org/tools/html-entity-encoder Category: Text Convert special characters to HTML entities (or back again) safely, entirely in your browser useful for escaping user content. FAQ: Q: Is HTML Entity Encoder/Decoder free to use? A: Yes, HTML Entity Encoder/Decoder is completely free with no sign-up, usage limits, or paywall. Q: Does HTML Entity Encoder/Decoder send my data to a server? A: No. HTML Entity Encoder/Decoder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use HTML Entity Encoder/Decoder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Lorem Ipsum Generator URL: https://simpledevtools.org/tools/lorem-ipsum-generator Category: Text Generate paragraphs, sentences, or words of classic Lorem Ipsum placeholder text instantly, with configurable length. FAQ: Q: Is Lorem Ipsum Generator free to use? A: Yes, Lorem Ipsum Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Lorem Ipsum Generator send my data to a server? A: No. Lorem Ipsum Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Lorem Ipsum Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. === ## Generators ### UUID Generator URL: https://simpledevtools.org/tools/uuid-generator Category: Generators Generate one or many RFC-4122 v4 UUIDs with a single click, fully client-side using the browser's crypto API. FAQ: Q: What's the chance of a UUID collision? A: For v4 UUIDs, the probability of two random values colliding is astronomically small (roughly 1 in 2.71 quintillion), making them safe for practical use as unique identifiers. Q: Is UUID Generator free to use? A: Yes, UUID Generator is completely free with no sign-up, usage limits, or paywall. Q: Does UUID Generator send my data to a server? A: No. UUID Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use UUID Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Are the generated values cryptographically random? A: Yes, generation uses the browser's crypto.getRandomValues API rather than Math.random, so output is suitable for IDs, tokens, and passwords. --- ### NanoID Generator URL: https://simpledevtools.org/tools/nanoid-generator Category: Generators Generate cryptographically secure NanoIDs with configurable length and alphabet, entirely client-side. FAQ: Q: Is NanoID Generator free to use? A: Yes, NanoID Generator is completely free with no sign-up, usage limits, or paywall. Q: Does NanoID Generator send my data to a server? A: No. NanoID Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use NanoID Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Are the generated values cryptographically random? A: Yes, generation uses the browser's crypto.getRandomValues API rather than Math.random, so output is suitable for IDs, tokens, and passwords. --- ### ULID Generator URL: https://simpledevtools.org/tools/ulid-generator Category: Generators Generate ULIDs unique, lexicographically sortable identifiers that encode a timestamp directly in your browser. FAQ: Q: Is ULID Generator free to use? A: Yes, ULID Generator is completely free with no sign-up, usage limits, or paywall. Q: Does ULID Generator send my data to a server? A: No. ULID Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use ULID Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Are the generated values cryptographically random? A: Yes, generation uses the browser's crypto.getRandomValues API rather than Math.random, so output is suitable for IDs, tokens, and passwords. --- ### QR Code Generator URL: https://simpledevtools.org/tools/qr-code-generator Category: Generators Enter any text, URL, or Wi-Fi credential string to generate a downloadable QR code, rendered entirely client-side. FAQ: Q: Do the generated QR codes expire? A: No. The QR code simply encodes your text or URL directly; it will work for as long as the underlying data (e.g. the destination URL) remains valid. Q: Is QR Code Generator free to use? A: Yes, QR Code Generator is completely free with no sign-up, usage limits, or paywall. Q: Does QR Code Generator send my data to a server? A: No. QR Code Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use QR Code Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Are the generated values cryptographically random? A: Yes, generation uses the browser's crypto.getRandomValues API rather than Math.random, so output is suitable for IDs, tokens, and passwords. --- ### Unix Timestamp Converter URL: https://simpledevtools.org/tools/timestamp-converter Category: Generators Paste a Unix timestamp (seconds or milliseconds) to convert it to a readable date, or go the other direction instantly, any timezone. FAQ: Q: Does this handle timestamps in seconds and milliseconds? A: Yes, it auto-detects whether your input is in seconds or milliseconds based on digit length and converts accordingly. Q: Is Unix Timestamp Converter free to use? A: Yes, Unix Timestamp Converter is completely free with no sign-up, usage limits, or paywall. Q: Does Unix Timestamp Converter send my data to a server? A: No. Unix Timestamp Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Unix Timestamp Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Are the generated values cryptographically random? A: Yes, generation uses the browser's crypto.getRandomValues API rather than Math.random, so output is suitable for IDs, tokens, and passwords. === ## AI / LLM ### LLM Token Counter URL: https://simpledevtools.org/tools/token-counter Category: AI / LLM Paste text or code to see an accurate token count for popular LLM tokenizers, helping you stay within context limits computed locally. FAQ: Q: Is LLM Token Counter free to use? A: Yes, LLM Token Counter is completely free with no sign-up, usage limits, or paywall. Q: Does LLM Token Counter send my data to a server? A: No. LLM Token Counter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use LLM Token Counter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: How accurate are the token counts? A: Counts are computed using the same tokenization logic as the target model's public tokenizer, so they closely match what you'd see billed, though exact parity can vary slightly by model version. --- ### OpenAI Pricing Calculator URL: https://simpledevtools.org/tools/openai-pricing-calculator Category: AI / LLM Enter input/output token counts and model to estimate the cost of an OpenAI API call, using up-to-date public pricing. FAQ: Q: Is OpenAI Pricing Calculator free to use? A: Yes, OpenAI Pricing Calculator is completely free with no sign-up, usage limits, or paywall. Q: Does OpenAI Pricing Calculator send my data to a server? A: No. OpenAI Pricing Calculator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use OpenAI Pricing Calculator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: How accurate are the token counts? A: Counts are computed using the same tokenization logic as the target model's public tokenizer, so they closely match what you'd see billed, though exact parity can vary slightly by model version. --- ### Context Window Calculator URL: https://simpledevtools.org/tools/context-window-calculator Category: AI / LLM Paste your prompt or conversation to see how many tokens it consumes relative to a given model's context window limit. FAQ: Q: Is Context Window Calculator free to use? A: Yes, Context Window Calculator is completely free with no sign-up, usage limits, or paywall. Q: Does Context Window Calculator send my data to a server? A: No. Context Window Calculator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Context Window Calculator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: How accurate are the token counts? A: Counts are computed using the same tokenization logic as the target model's public tokenizer, so they closely match what you'd see billed, though exact parity can vary slightly by model version. === ## DevOps ### Docker Compose to Kubernetes Converter URL: https://simpledevtools.org/tools/docker-compose-to-kubernetes Category: DevOps Paste a docker-compose.yml file and get equivalent Kubernetes Deployment and Service YAML manifests, generated entirely in your browser. FAQ: Q: Is Docker Compose to Kubernetes Converter free to use? A: Yes, Docker Compose to Kubernetes Converter is completely free with no sign-up, usage limits, or paywall. Q: Does Docker Compose to Kubernetes Converter send my data to a server? A: No. Docker Compose to Kubernetes Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Docker Compose to Kubernetes Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. --- ### Kubernetes YAML Validator URL: https://simpledevtools.org/tools/k8s-yaml-validator Category: DevOps Paste a Kubernetes manifest to check for YAML syntax errors and common schema issues before you apply it to a cluster. FAQ: Q: Is Kubernetes YAML Validator free to use? A: Yes, Kubernetes YAML Validator is completely free with no sign-up, usage limits, or paywall. Q: Does Kubernetes YAML Validator send my data to a server? A: No. Kubernetes YAML Validator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Kubernetes YAML Validator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. --- ### Cron Expression Parser URL: https://simpledevtools.org/tools/cron-parser Category: DevOps Paste a cron expression to see a plain-English explanation and a preview of the next upcoming run times. FAQ: Q: Does this account for timezone differences? A: Next-run previews are calculated based on your browser's local timezone. If your scheduler runs in UTC or another timezone, adjust accordingly. Q: Is Cron Expression Parser free to use? A: Yes, Cron Expression Parser is completely free with no sign-up, usage limits, or paywall. Q: Does Cron Expression Parser send my data to a server? A: No. Cron Expression Parser runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Cron Expression Parser on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. --- ### Dockerfile Linter URL: https://simpledevtools.org/tools/dockerfile-linter Category: DevOps Paste a Dockerfile to catch common mistakes missing tags, inefficient layer ordering, running as root, and more. FAQ: Q: Is Dockerfile Linter free to use? A: Yes, Dockerfile Linter is completely free with no sign-up, usage limits, or paywall. Q: Does Dockerfile Linter send my data to a server? A: No. Dockerfile Linter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Dockerfile Linter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. --- ### Helm Values Generator URL: https://simpledevtools.org/tools/helm-values-generator Category: DevOps Answer a few quick questions to generate a starter values.yaml file for a Helm chart, ready to customize. FAQ: Q: Is Helm Values Generator free to use? A: Yes, Helm Values Generator is completely free with no sign-up, usage limits, or paywall. Q: Does Helm Values Generator send my data to a server? A: No. Helm Values Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Helm Values Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. --- ### .env to Docker Compose Converter URL: https://simpledevtools.org/tools/env-to-docker-compose Category: DevOps Paste a .env file and get the equivalent environment block ready to drop into a docker-compose.yml service. FAQ: Q: Is .env to Docker Compose Converter free to use? A: Yes, .env to Docker Compose Converter is completely free with no sign-up, usage limits, or paywall. Q: Does .env to Docker Compose Converter send my data to a server? A: No. .env to Docker Compose Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use .env to Docker Compose Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. Q: Does this replace validating against my actual cluster/CI? A: No. This tool catches common syntax and structural issues locally, but you should still validate against your real environment (kubectl apply --dry-run, CI lint step, etc.) before deploying. === ## API ### cURL Command Builder URL: https://simpledevtools.org/tools/curl-builder Category: API Fill in method, URL, headers, and body to generate a ready-to-paste cURL command no need to remember flag syntax. FAQ: Q: Is cURL Command Builder free to use? A: Yes, cURL Command Builder is completely free with no sign-up, usage limits, or paywall. Q: Does cURL Command Builder send my data to a server? A: No. cURL Command Builder runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use cURL Command Builder on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### HTTP Header Analyzer URL: https://simpledevtools.org/tools/http-header-analyzer Category: API Paste a set of HTTP headers to get a breakdown of what each one does, plus flags for missing security-relevant headers. FAQ: Q: Is HTTP Header Analyzer free to use? A: Yes, HTTP Header Analyzer is completely free with no sign-up, usage limits, or paywall. Q: Does HTTP Header Analyzer send my data to a server? A: No. HTTP Header Analyzer runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use HTTP Header Analyzer on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### CIDR / Subnet Calculator URL: https://simpledevtools.org/tools/cidr-calculator Category: API Enter a CIDR block to see network address, broadcast address, usable host range, and total host count instantly. FAQ: Q: Does this support IPv6 CIDR blocks? A: This tool is built for IPv4 CIDR notation. IPv6 subnetting follows different rules and isn't covered here. Q: Is CIDR / Subnet Calculator free to use? A: Yes, CIDR / Subnet Calculator is completely free with no sign-up, usage limits, or paywall. Q: Does CIDR / Subnet Calculator send my data to a server? A: No. CIDR / Subnet Calculator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use CIDR / Subnet Calculator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### User-Agent Parser URL: https://simpledevtools.org/tools/user-agent-parser Category: API Paste any User-Agent string to break it down into browser name/version, operating system, and device type. FAQ: Q: Is User-Agent Parser free to use? A: Yes, User-Agent Parser is completely free with no sign-up, usage limits, or paywall. Q: Does User-Agent Parser send my data to a server? A: No. User-Agent Parser runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use User-Agent Parser on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### GraphQL Query Formatter URL: https://simpledevtools.org/tools/graphql-formatter Category: API Paste a minified or messy GraphQL query or schema and get a clean, properly indented version back. FAQ: Q: Is GraphQL Query Formatter free to use? A: Yes, GraphQL Query Formatter is completely free with no sign-up, usage limits, or paywall. Q: Does GraphQL Query Formatter send my data to a server? A: No. GraphQL Query Formatter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use GraphQL Query Formatter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. === ## Design ### Color Converter URL: https://simpledevtools.org/tools/color-converter Category: Design Enter a color in any format HEX, RGB, or HSL and instantly see it converted to the others, with a live preview swatch. FAQ: Q: Is Color Converter free to use? A: Yes, Color Converter is completely free with no sign-up, usage limits, or paywall. Q: Does Color Converter send my data to a server? A: No. Color Converter runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Color Converter on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### CSS Gradient Generator URL: https://simpledevtools.org/tools/css-gradient-generator Category: Design Pick colors and angles to build a CSS gradient visually, then copy the generated gradient code directly into your stylesheet. FAQ: Q: Is CSS Gradient Generator free to use? A: Yes, CSS Gradient Generator is completely free with no sign-up, usage limits, or paywall. Q: Does CSS Gradient Generator send my data to a server? A: No. CSS Gradient Generator runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use CSS Gradient Generator on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required. --- ### Color Contrast Checker URL: https://simpledevtools.org/tools/contrast-checker Category: Design Enter a foreground and background color to check contrast ratio against WCAG AA/AAA thresholds for accessible text. FAQ: Q: Is Color Contrast Checker free to use? A: Yes, Color Contrast Checker is completely free with no sign-up, usage limits, or paywall. Q: Does Color Contrast Checker send my data to a server? A: No. Color Contrast Checker runs entirely client-side in your browser. Nothing you enter is transmitted or stored anywhere, so it's safe to use with sensitive data. Q: Can I use Color Contrast Checker on mobile? A: Yes, it works on any modern mobile or desktop browser since it's a lightweight, client-side tool with no app install required.