JWT decoder
Read the header and claims, check expiry, verify HS, RS, and ES signatures, and sign with a shared secret.
/tools · 7 tools
Developer tools that stay in your browser
The small jobs that usually mean a tab on someone else's site: decode a token, tidy JSON, convert a timestamp, hash a file. Each one runs in this page. Nothing you paste is sent anywhere.
/all
Every tool
Client-side only, built on the browser's own WebCrypto, URL, and Intl APIs. The source ships in the site repository like everything else CAVI publishes.
JSON formatter
Pretty-print with 2, 4, or tab indentation, minify, sort keys, and see the line and column of the first error.
Base64
Text or files in, standard or URL-safe alphabet out, with padding optional. Decodes either alphabet.
URL encoder
Percent-encode a component, a whole URL, or a form value, decode either, and break a URL into its parts.
Timestamp converter
Unix seconds, milliseconds, ISO 8601, RFC 7231, ISO week, and any IANA time zone from one input.
UUID generator
Random v4 or time-ordered v7 in bulk, upper or lower case, with or without dashes. Inspect any UUID.
Hash calculator
Digest text or a file with every SHA variant at once, as hex or Base64, optionally keyed as an HMAC.