Free developer tools that run entirely in your browser
Format, validate, decode and generate — JSON, JWT, regex, UUIDs, hashes, timestamps and encodings. Because nothing is uploaded, these are safe to use on production payloads, tokens and customer data.
The 14 tools in this set
JSON Formatter & Validator
Format, minify and validate JSON in one click.
JSON MinifierShrink JSON to its smallest size.
JWT DecoderDecode JWT tokens without a server.
JWT GeneratorCreate signed JWTs from scratch.
Regex TesterTest regular expressions live against your text.
UUID GeneratorGenerate v4 UUIDs instantly, in bulk.
Timestamp ConverterConvert Unix timestamps to dates and back.
Base64 Encoder / DecoderEncode or decode text to and from base64.
URL Encoder / DecoderEncode or decode URL strings safely.
Hash GeneratorHash text with MD5 and every SHA.
Checksum GeneratorCRC32 checksums for your files.
HTTP Status Code LookupLearn what every HTTP status means.
CSV to JSONConvert CSV into clean, readable JSON.
JSON Diff CheckerCompare two JSON structures.
A sensible order to work in
- Paste, do not upload — Tokens, payloads and customer data stay in the tab you are looking at.
- Validate before you ship — A formatter that also reports the parse error saves a deploy cycle.
- Generate what you need locally — UUIDs, secrets and hashes are produced by your browser, not a server you have to trust.
Categories this set draws from
Web developers tools — FAQ
Is it safe to paste a JWT here?
Yes. Decoding happens locally in your browser — the token is never transmitted.
Do these work offline?
Once the page has loaded, yes. There is no server call in the tool itself.
Can I use the output in production?
Yes, the output is yours with no attribution or watermark.