Dev Tools

🔒 Runs entirely in your browser — nothing is uploaded

JWT decoder

Decode a JSON Web Token's header and payload. Not verified — decoding only, in your browser.

HEADER
PAYLOAD

JSON formatter & validator

Pretty-print, minify, or validate JSON.

Base64 encode / decode

Unicode-safe (UTF-8). Handles emoji and non-ASCII correctly.

Hash / checksum

SHA-1, SHA-256, SHA-384, SHA-512 of your text, computed with the browser's native crypto.

On brand: the SHA-256 here is exactly how every HEXAQA test file's published digest is computed — download a file, hash it, and it matches the value in the catalog.

UUID generator

Cryptographically-random UUID v4, generated locally.

Timestamp / epoch converter

Convert between Unix time and human dates. Seconds vs milliseconds auto-detected.

URL parser

Break a URL into its parts and decode the query string.