JSON Formatter, API Tester Kit

Free JSON formatter, REST API tester, JWT decoder, regex tester, hash generator, Base64 & URL encoder, timestamp converter and UUID generator — all in one lightweight Android app. The only mobile dev toolkit with a built-in REST API client. Stop installing ten different utilities. Dev Toolkit puts every essential developer tool in one fast, offline-friendly app — built for Android developers, backend engineers, QA testers and DevOps. ══════════════════════ WHY DEVELOPERS PICK DEV TOOLKIT ══════════════════════ • 9 essential dev tools in 1 free app • Built-in REST API tester — most multi-tool apps don't have one • Most tools work fully offline • Clean interface — no interruptive ads in the middle of your work • One-tap copy & share • Opens in under a second • No sign-up required ══════════════════════ EVERY TOOL YOU NEED ══════════════════════ ▸ JSON FORMATTER, VIEWER & VALIDATOR The fastest JSON formatter for Android. Beautify, validate, minify and pretty-print JSON instantly with syntax highlighting — a powerful mobile alternative to JSONLint and online JSON viewers. • Beautify & prettify JSON for readability • Minify JSON for compact API payloads • Built-in JSON validator with error highlighting • Copy formatted output in one tap ▸ REST API TESTER (Postman alternative) — exclusive in this app A lightweight HTTP client and REST API tester for Android. Send GET, POST, PUT, PATCH and DELETE requests with custom headers, query params and JSON bodies. The pocket-sized Postman alternative for debugging APIs on the go. Most multi-tool dev apps skip this — Dev Toolkit ships it as a first-class tool. • Test REST APIs from your phone • Custom headers and query parameters • JSON request body support • Pretty-formatted responses with status colors ▸ JWT DECODER (JSON Web Token) Decode and inspect any JWT token instantly. View the header, payload, claims and expiry time — perfect for OAuth, Firebase Auth, bearer tokens and API debugging. • Decode JWT header & payload • Pretty-formatted JSON output • View issued-at and expiry times • Copy individual claims with one tap ▸ REGEX TESTER (Regular Expression) Build and test regular expressions on the fly with live match highlighting — great for text parsing, log scraping and form validation. ▸ HASH GENERATOR (MD5, SHA-1, SHA-256, SHA-512) Generate cryptographic hashes and checksums instantly for data integrity verification, password hashing demos and debugging. ▸ TIMESTAMP CONVERTER (Unix / Epoch time) Convert Unix timestamps to readable dates and vice versa. Auto-detects seconds vs milliseconds and shows UTC, local and relative time (e.g. "5 minutes ago"). ▸ UUID / GUID GENERATOR Generate UUID v4 IDs for databases, API tests and mock data. Batch generation with uppercase and no-hyphen options. ▸ BASE64 ENCODER & DECODER Encode and decode Base64 strings instantly — handy for API payloads, Basic Auth headers and embedded data. ▸ URL ENCODER & DECODER Encode and decode URLs and query parameters for debugging query strings, deep links and redirects. ══════════════════════ PERFECT FOR ══════════════════════ • Android & mobile developers • Backend & API engineers • Web developers • DevOps & SRE engineers • QA testers & automation engineers • Computer science students • Anyone learning REST APIs, JSON or regex ═════════════════════ ALSO KNOWN AS ═════════════════════ json formatter, json viewer, json beautifier, json parser, json validator, json pretty print, rest api client, api tester, http client, postman alternative, jwt decoder, regex tester, hash generator, md5 generator, sha256 generator, base64 decoder, url decoder, timestamp converter, epoch converter, unix time, uuid generator, guid generator, developer tools, dev tools, programmer tools, coding tools, android developer tools. Download Dev Toolkit now — the only developer tools app you'll need on Android. 100% free. No sign-up. Most tools work offline. Have feedback or a tool request? Email us — we ship updates every month.