Developer Tools
12 free browser-based utilities — JSON, base64, regex, JWT, UUID, hashes, cron, and more.
Developer utilities. Nothing leaves your browser.
12 free tools every backend, frontend, and DevOps engineer needs on a daily basis. JSON formatter, base64, regex, JWT, UUID, hash, cron, timestamps. All 100% client-side — your data never touches a server.
JSON Formatter
Format, minify, and validate JSON. 2/4/none indent options.
Base64 Encoder / Decoder
Two-way conversion — text ↔ base64. Full Unicode support.
URL Encoder / Decoder
Percent-encode URLs and query strings, or reverse.
JWT Decoder
Decode JWT header and payload. No signature verification — client-side only.
Regex Tester
Test regular expressions with live match highlighting and group capture.
Timestamp Converter
Unix ↔ ISO 8601 ↔ local time. Auto-detects seconds vs milliseconds.
UUID Generator
Generate v4 UUIDs (1-1000 at a time). Uppercase, hyphen-strip options.
Password Generator
Cryptographically secure passwords. Length + charset + ambiguity control.
Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512 via WebCrypto. All in one pass.
Cron Parser
Turn cron expressions into plain English + preview the next 5 fire times.
CSS Color Converter
Live sync between HEX, RGB, and HSL. Visual preview.
Case Converter
camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and 6 more.
Why client-side matters
Every tool here runs entirely in your browser tab — the JSON you paste, the JWT you decode, the password you generate, none of it is transmitted anywhere. That's important because these tools handle sensitive data: JWTs contain user identity, JSON often contains API responses with private keys or personal information, and passwords should never leave the device that generates them. Our implementation uses only the browser's built-in WebCrypto API and pure JavaScript — no third-party libraries, no analytics on tool operations, no network requests once the page has loaded.