Developer Tools
Developer tools cover the small tasks that interrupt a working day: pretty-printing a JSON payload, validating XML, minifying CSS before a deploy, decoding a JWT while debugging an API, generating UUIDs, testing a regular expression or looking up an HTTP status code. Formatting and validation run in your browser so unreleased code and production payloads stay local.
Most used in this category
- JSON Formatter Beautify, validate and sort JSON with precise error messages. In your browser
- JSON Validator Check whether JSON is valid and see exactly where it breaks. In your browser
- SQL Formatter Reformat dense SQL into readable, indented statements. In your browser
- HTML Formatter Indent HTML and make nested markup readable. In your browser
All developer tools
41 tools- JSON Formatter Beautify, validate and sort JSON with precise error messages. In your browser
- JSON Validator Check whether JSON is valid and see exactly where it breaks. In your browser
- JSON Minifier Strip whitespace from JSON and see the size saved. In your browser
- XML Formatter Indent XML so nested documents become readable. In your browser
- XML Validator Check that an XML document is well-formed. In your browser
- SQL Formatter Reformat dense SQL into readable, indented statements. In your browser
- HTML Formatter Indent HTML and make nested markup readable. In your browser
- HTML Minifier Shrink HTML by removing whitespace and comments. In your browser
- CSS Formatter Expand minified CSS into readable, indented rules. In your browser
- CSS Minifier Compress CSS by removing whitespace and comments. In your browser
- JavaScript Formatter Re-indent JavaScript so minified code becomes readable. In your browser
- JavaScript Minifier Strip comments and whitespace from JavaScript safely. In your browser
- UUID Generator Generate random v4 or time-ordered v7 UUIDs in bulk. In your browser
- Regex Tester Test a regular expression and see every match highlighted. In your browser
- Unix Timestamp Converter Convert between Unix timestamps and human dates. In your browser
- Text to Binary Converter Convert text to binary, hex, octal or decimal and back. In your browser
- JWT Decoder Read a JSON Web Token header, payload and expiry. In your browser
- Color Converter Convert colours between HEX, RGB, HSL and HSV. In your browser
- HTTP Status Code Reference Search every HTTP status code and what it means. In your browser
- MIME Type Lookup Find the MIME type for any file extension, and back. In your browser
- QR Code Generator Create a downloadable QR code from a link or text. Server-side
- JSON Diff Compare two JSON documents and see exactly what changed. In your browser
- JSON Flatten Turn nested JSON into a flat map of dot-separated paths. In your browser
- JSON Unflatten Rebuild nested JSON from a flat map of dot-separated paths. In your browser
- JSON Merge Combine two JSON documents, with control over how arrays behave. In your browser
- JSON Escape and Unescape Escape text for use inside a JSON string, or decode it back. In your browser
- NDJSON Formatter Convert between NDJSON line-delimited records and a JSON array. In your browser
- JSON to TypeScript Generate TypeScript interfaces from a sample JSON payload. In your browser
- URL Parser Split a URL into its scheme, host, path, query and fragment. In your browser
- Query String Parser Decode a query string into a readable table of parameters. In your browser
- HTTP Header Parser Turn a raw header block into a readable table. In your browser
- Cron Expression Parser Explain a cron expression in plain English and show its next runs. In your browser
- Number Base Converter Convert numbers between any bases from 2 to 36. In your browser
- Email Address Validator Check a list of email addresses for syntax errors. In your browser
- Random Number Generator Generate random whole numbers in a range you choose. In your browser
- UUID Validator Check UUIDs and identify which version each one is. In your browser
- JSON Schema Validator Check a JSON document against a JSON Schema and see every failure. In your browser
- JSON Tree Viewer Explore a large JSON document as a collapsible tree. In your browser
- Cron Expression Generator Build a cron expression from a schedule, and see when it will run. In your browser
- Meta Tag Generator Generate the meta, Open Graph and Twitter tags for a page. In your browser
- robots.txt Generator Build a valid robots.txt, with or without the AI crawlers. In your browser
Developer Tools: frequently asked questions
Can I paste a production payload safely?
Formatters, validators, minifiers, decoders and generators run entirely in your browser and transmit nothing. The one exception is the QR code generator, which renders on our server; every page states its processing model in a badge near the top.
Does the JWT decoder verify signatures?
No, and that is deliberate. Verifying a signature would require you to paste a secret or private key. The decoder only reads the header and payload, and the page states clearly that decoded claims are not trustworthy until your own backend verifies them.
Are the formatters safe to use on minified third-party code?
Yes. The formatters only change whitespace between tokens; string literals, template literals, regular expressions and comments are preserved byte for byte.
Other categories
All tools →- Text Tools Count, clean, reformat and analyse written text.
- Data Conversion Tools Move data between CSV, JSON, XML, YAML and TSV.
- Extraction Tools Pull emails, URLs, numbers and dates out of messy text.
- Network & Web Tools Inspect DNS, IP addresses, headers and redirects.
- Encoding & Security Tools Encode, hash, sign and generate strong secrets.