Format, validate, minify and convert JSON, SQL, HTML, CSS, JS, XML, YAML and CSV. Decode JWT, generate UUIDs and hashes, test regex and APIs, parse URLs and cron expressions — all client-side, all free.
Test regular expressions with input text, show matches, groups, and replacements.
Launch ToolDecode JSON Web Tokens to see header, payload, and signature. Validate expiration.
Launch ToolParse cron expressions and show next 10 execution times in human-readable format.
Launch ToolTest REST APIs in your browser — send GET/POST/PUT/DELETE with custom headers and body.
Launch ToolEncode and decode HTML entities for special characters.
Launch ToolConvert numbers between Binary, Octal, Decimal, and Hexadecimal bases.
Launch ToolEncode, decode, and build URLs with live query-parameter editing and batch support.
Launch ToolParse any URL into its components — protocol, host, path, and query params.
Launch ToolConvert cURL commands into JavaScript (Fetch, Axios), Python (Requests, HTTPX), Go, PHP, and Rust code instantly.
Launch ToolConvert HTML code into clean React JSX components with camelCase properties, class to className, and style objects.
Launch ToolThese tools replace the small one-off scripts developers reach for daily — prettify a JSON response, decode a JWT to see when it expires, generate a UUID for test fixtures, hash a string to verify a checksum, or sanity-check a regex against sample input. Doing it in the browser skips the install, the script file, and the network round-trip.
Coverage spans code formatters (JSON, SQL, HTML, CSS, JS, XML), minifiers (HTML, CSS, JS), encoders & hashes (Base64, HTML entities, MD5–SHA-512), IDs & timestamps (UUID, cron parser, Unix timestamp converter), API & URL utilities (API tester, URL parser, URL encoder, number-base converter), and data converters (JSON↔CSV, JSON↔YAML, XML↔JSON, JSON diff). For CSS visual generators — box-shadow, border-radius, gradients, and the WCAG contrast checker — see the Color & Design hub.
Putting the toolkit in a tab means there is no npm install, no node_modules bloat, and no CLI to forget the syntax of. Open the page, paste your input, get the output — your payloads never leave the development machine, which matters when you are debugging against production-shaped JWTs or scrubbing real API responses.
Every formatter, validator and decoder runs in your browser. No payloads are uploaded to a server.
No API keys, no rate limits, no signups — the full developer toolkit is free forever.
Client-side processing means instant results — even with no network connection.