Free JSON, CSV & Developer Tools — Private, In-Browser
Developer utilities that run entirely client-side: pretty-print and validate JSON, convert CSV to JSON and back, generate UUID v4 values in bulk, test JavaScript regular expressions against sample text, and decode JWTs without sending them anywhere.
JSON is parsed with the native parser, UUIDs come from crypto.getRandomValues, and the regex flavour is the same ECMAScript engine that will run your pattern in production. Debug real payloads without leaking them to a third-party service.
Data & Dev tools
Data & Dev
JSON Formatter
Validate & pretty-print
Validate, format, minify and inspect JSON with error messages and key stats.…
Data & Dev
CSV to JSON
CSV → JSON
Convert CSV to JSON with header detection, delimiter choice and preview.…
Data & Dev
JSON to CSV
JSON → CSV
Flatten an array of objects to CSV. Handles nested keys with dot notation.…
Data & Dev
UUID Generator
Bulk v4 UUIDs
Generate cryptographically random UUID v4s in bulk. Copy or download as text.…
Data & Dev
Regex Tester
Test JS regex live
Test JavaScript regular expressions against sample text with match highlighting and groups.…
Data & Dev
JWT Decoder
Decode header/payload
Decode JWT header and payload locally. Signature is NOT verified — never paste secrets.…
Data & Dev
Password Generator
Secure random
Generate strong random passwords with length and character controls. Uses crypto RNG.…