Free Developer Tools
JSON formatter, Base64, hashes, UUIDs, JWT decoder, regex tester and diff checker. Fast developer utilities that run locally in your browser.
- No upload — 100% private
- Instant, on your device
- Free, no sign-up
- Works offline once loaded
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JSON Formatter
Beautify, validate, minify and explore JSON as a tree.
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Base64 Encode & Decode
Encode or decode Base64 text, files, images and data URIs.
URL Encode & Decode
Percent-encode, decode and edit URL query parameters.
Hash Generator
MD5, SHA-1, SHA-256, SHA-512 and HMAC for text or files.
UUID Generator
Generate v4 and v7 UUIDs in bulk, then validate and decode.
JWT Decoder
Decode JWT header and payload, check expiry, verify HMAC.
Regex Tester
Test JavaScript regular expressions with live highlighting.
Diff Checker
Compare two texts side by side with word-level highlights.
Markdown Preview
Live Markdown editor with GitHub-flavored preview and HTML export.
Unix Timestamp Converter
Convert epoch timestamps to dates and back in any time zone.