Developer tools
Format JSON, encode and decode Base64 and URLs, generate UUIDs and hashes, test regular expressions and read JWTs. Everything runs locally, so tokens and payloads stay on your machine.
Tools in this category
4 tools-
JSON formatter
Format, minify and check JSON, with the line and column of the first error. -
JWT Decoder
Read token contents and dates. Signatures are not verified. -
URL encoder and decoder
Encode text for URLs or decode percent escapes as you type. -
UUID generator
Create secure random v4 or timestamp-based v7 UUIDs in batches.
These are the quick checks you reach for while debugging: is this JSON valid and where is the error, what does this Base64 string contain, what is in this JWT, does my regex match the line I think it does. Each tool works on the input as you type and reports errors with line and column numbers where that helps. Hashing uses the browser's WebCrypto API, so a SHA-256 of a large file is computed in a worker without uploading the file. Base64 handles files as well as text and switches to a worker above a few megabytes. The JWT decoder shows the header and payload and turns timestamps into readable dates, but it does not verify signatures, and it says so on the page. Because nothing is sent to a server, it is safe to paste production tokens, API responses and configuration here.
Common questions
Can I safely paste API keys and tokens into these tools?
Yes. The developer tools do not send input anywhere; decoding, formatting and hashing happen in your browser. Still, treat the browser tab like any other place you paste a secret: close it when you are done and do not use a shared or public computer for production credentials.
Do the hash tools support files?
Yes. The hash generator accepts files of any size and reads them in chunks inside a Web Worker, so the page stays responsive. The file is never uploaded. MD5 is provided for legacy checksums; use SHA-256 or stronger for anything security related.