DevTools
Free online developer tools: JSON formatter, Base64, hash, JWT, UUID, regex, timestamp, color and base converters.
DevTools is a free collection of browser-based developer utilities — no install, no sign-up. Format JSON, encode Base64, generate SHA hashes, decode JWTs, create UUIDs, test regex, and convert timestamps, colors and number bases instantly.
Everything runs client-side in your browser. The JSON, tokens and text you paste are never sent to or stored on a server.
Developer tools
JSON Formatter / Validator
Beautify or minify JSON and validate it to pinpoint the line and column of syntax errors.
Base64 Encoder / Decoder
Convert text and Base64 both ways with full UTF-8 safety.
Hash Generator (SHA)
Generate SHA-1/256/384/512 hashes in the browser with Web Crypto.
JWT Decoder
Base64URL-decode a JWT's header and payload and display them as JSON.
UUID Generator
Generate RFC 4122 v4 UUIDs in bulk by count.
Regex Tester
Highlight matches in a test string using your pattern and flags.
Unix Timestamp Converter
Convert between epoch time and human dates both ways.
Color Converter
Convert HEX, RGB and HSL color codes both ways with live preview.
Base Converter
Convert between binary, octal, decimal and hexadecimal.
Developer guides
Why use DevTools
- Free and install-free — use everything straight from the browser, no sign-up or app required.
- Fully client-side — JSON, JWTs, text and other input are processed only in your browser and never sent to a server. Sensitive tokens and data stay safe.
- Standard browser APIs — hashing uses Web Crypto (SubtleCrypto), UUIDs use crypto.randomUUID, and other proven built-ins.
- No external dependencies beyond ads — runs on plain JavaScript with no third-party libraries or CDNs.
Each tool is a development aid. For security-critical work (such as signature verification) re-check results in a trusted server environment.
Last updated: 2026-06-25