Free Developer Tools — The Complete Collection

Format, validate, and minify JSON data. Detects syntax errors with precise line/column numbers. Supports JSON Schema validation for Draft 07 and 2020-12. Ideal for debugging API responses and editing configuration files like tsconfig, .eslintrc, or VS Code settings.

Beautify or minify code in 17 languages: JavaScript, TypeScript, HTML, CSS, JSON, Python, XML, SQL, YAML, GraphQL, Rust, Go, Java, C#, PHP, Ruby, and Bash. Each language has language specific formatting rules. Toggle minify mode for production output.

Compare two blocks of text or code side by side and see additions, removals, and changes highlighted. Supports ignore whitespace mode and file upload. Essential for code review, configuration comparison, and debugging content changes.

Beautify and clean up messy markdown. Fix malformed tables, normalize spacing and indentation, correct bold/italic formatting, normalize horizontal rules, and optionally add language hints to code blocks. Free client-side tool.

Encode text or files to Base64 and decode Base64 back to readable text. Supports file upload with preview. Handles large payloads comfortably. Commonly used for embedding binary data in web pages, API payloads, and data URLs.

Encode special characters into URL-safe percent-encoding and decode URL-encoded strings back. Essential for building query strings, form URL encoding, and debugging malformed URLs in API requests.

Convert hex color codes (#FF6600) to RGB (rgb(255, 102, 0)) and HSL values. Preview the colour instantly. Useful for designers and developers working across CSS, design tokens, and graphics code.

Convert between binary, decimal, octal, and hexadecimal number systems. Includes ASCII text to binary conversion and bitwise utility operations. Handy for low-level debugging, embedded systems work, and understanding how data is represented in memory.

Convert JSON arrays of objects to CSV and CSV back to JSON. Handles nested objects, custom delimiters, and large datasets. Perfect for migrating data between databases, spreadsheets, and API payloads.

Convert YAML to JSON and JSON to YAML with live preview and error highlighting. Supports custom indentation and key sorting. Useful for translating between Kubernetes manifests (YAML) and API payloads (JSON), or between Docker Compose files and configuration services.

Generate cryptographically strong passwords with customizable length (up to 128 characters). Toggle uppercase, lowercase, digits, and symbols independently. Uses crypto.getRandomValues() for true randomness — passwords never leave your browser. Designed for API keys, database credentials, admin accounts, and SSH passphrases.

Compute MD5, SHA-1, SHA-256, SHA-512, and HMAC hashes from text input. Supports batch processing (one hash per line). Useful for verifying file integrity, generating checksums, and building HMAC signed API requests.

Decode the header and payload of any JSON Web Token. View claims like issuer (iss), subject (sub), expiration (exp), and custom claims. Shows an automatic expiry countdown. Useful for debugging OAuth flows, verifying token contents, and inspecting authentication headers.

Generate universally unique identifiers (UUIDs) in versions 1, 3, 4, and 5. Supports bulk generation (multiple UUIDs at once). Uses crypto.randomUUID() for v4 and custom namespace/UUID pairs for v3 and v5. Essential for database primary keys, API resource identifiers, and distributed system IDs.

Test regular expressions in real time. View all matches, capture groups, named groups, and replacement results. Supports common flags (g, i, m, s, u, y). Use the JavaScript mode for .match() and .replace() patterns, or the Python mode for re module patterns. Includes a cheat sheet for quick reference.

Generate regex patterns automatically from example text and target matches. Enter the strings you want to match and the tool detects the pattern using intelligent analysis — email, URL, IP, date, hex color, or a generalized character-class pattern. Test the generated pattern live against sample text.

Write Markdown with live HTML preview. Supports headings, lists, code blocks, tables, images, and links. Auto-saves your content to localStorage. Export formatted output as text. Perfect for drafting README files, documentation, or blog posts before committing.

Write HTML, CSS, and JavaScript and see the result rendered in a live preview iframe. Includes popular CSS libraries (Tailwind, Bootstrap). Ideal for prototyping UI components, testing layout ideas, or creating embeddable widgets without setting up a local dev environment.

Generate QR codes from URLs, text, or any string. Choose size and download as PNG. Privacy note: QR generation happens via an API call, while decoding is done client-side.

Upload an image containing a QR code and extract the encoded text. Full client-side decoding — your images are never uploaded to a server. Useful for scanning QR codes from screenshots, product packaging, or business cards.

Generate realistic mock webhook payloads for Stripe (payment events), GitHub (push, pull request, issue events), and Shopify (order, product events). View the full payload structure, headers, and sample responses. Useful for testing webhook handlers, building integrations, and understanding third-party API event formats.

Find your public IP address, ISP, city, region, country, coordinates, timezone, and ASN. Supports custom IP lookup — check any public IP address. Uses ip-api.com for geolocation data. No signup, no API keys, all client-side.

Paste an HTTP response (status line, headers, body) and get a formatted breakdown. See the status code meaning, header table, and syntax highlighted body. Supports JSON and XML responses. Useful for debugging HTTP clients, inspecting proxy output, and learning HTTP protocol details.

Convert a cURL command into ready-to-use code snippets for JavaScript fetch, Axios, Python requests, and Go. Parses URL, method, headers, and body from the cURL string. Saves time when translating API examples from documentation into your language of choice.

Convert Unix epoch timestamps (seconds and milliseconds) to human readable dates and vice versa. Auto detects seconds vs milliseconds. Shows UTC and local time, day of the week, ISO 8601 format, and relative time. Handles negative timestamps (pre-1970) and the year 2038 boundary.

Build cron expressions visually with a human readable translation. Select minute, hour, day of month, month, and day of week from dropdowns. Shows the expression in standard 5-field format. Useful for scheduling cron jobs, CI/CD pipeline triggers, and serverless function schedules.

Decode any cron expression into plain English. Paste a cron string like "*/15 * * * 1-5" and read the schedule described in simple language. Supports standard 5-field expressions, @-presets, ranges, steps, and lists. The inverse of the Cron Expression Builder.