Developer Tools that just work

70+ free, private, offline-capable tools for developers and testers. No accounts. No tracking. Everything runs in your browser.

Universal InspectorPaste anything, we route it to the right tool
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8 categories, 70+ tools

Encoders & Converters
Transform data between formats — Base64, URL, JSON↔YAML, hex, and more.
→ 10 tools
Formatters & Validators
Beautify and validate JSON, XML, YAML, SQL, HTML, CSS, regex, and more.
→ 12 tools
Crypto & Security
Hash, HMAC, AES, RSA, JWT, X.509, bcrypt, passwords — all client-side.
→ 7 tools
Generators
UUID, ULID, NanoID, fake data, mock JSON, QR codes, lorem ipsum, and more.
→ 10 tools
Network & Web
REST client, headers inspector, IP geo, CIDR calc, DNS, user-agent parser.
→ 10 tools
Date, Time & Math
Unix timestamps, timezone converter, date diff, cron builder, number base.
→ 6 tools
Text & String Tools
Word counter, sort/dedupe, find/replace, validators, lorem ipsum.
→ 4 tools
Frontend & Design
Color picker, WCAG contrast, gradient/shadow builder, code-to-image.
→ 7 tools
Base64 Encode / Decode
Base64 encode or decode any text or binary data instantly in your browser. Supports standard Base64, URL-safe Base64, and padding-free variants used in JWT tokens, data URIs, HTTP Basic Auth, and email attachments. No data leaves your device.
JSON Formatter & Validator
JSON formatter and validator — beautify, minify, or validate JSON online instantly. Configurable 2-space, 4-space, or tab indentation. Inline error highlighting shows exactly where your JSON is broken. Handles nested objects and large payloads. No sign-up, 100% free.
Regex Tester
Regex tester — test and debug regular expressions online with instant match highlighting. See all matches, capture group values, and named groups at a glance. Supports all JavaScript regex flags (g, i, m, s, u). Built-in find-and-replace mode. Free, no install.
Hash Generator
Hash generator — compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 cryptographic hashes instantly in your browser. Uses the WebCrypto API for SHA hashes — no server required. Paste text or upload a file. Ideal for verifying checksums and generating fingerprints.
JWT Decoder
JWT decoder — decode and inspect JSON Web Tokens instantly in your browser. View the decoded algorithm header, payload claims (sub, iat, exp, aud, iss), and expiration status. Flags expired tokens automatically. No signature verification — safe for debugging without exposing your secret key.
UUID Generator
UUID generator — create UUID v4 (cryptographically random) or UUID v7 (time-ordered, RFC 9562) identifiers instantly. Bulk-generate up to 100 UUIDs at once and download as a text file. UUID v7 is ideal for database primary keys — it is lexicographically sortable and avoids index fragmentation.

Dev Tools !?

100% Private

Your data never leaves your browser. No servers process your input.

Works Offline

Install as a PWA and use all tools without internet access.

Blazing Fast

Static pre-rendered pages. Tools run instantly in your browser.

Open & Auditable

Tool logic is open source and independently verifiable.