Developer Tools

Safe for tokens and payloads

Developers routinely paste API responses, auth tokens and config files into online tools, and most of those tools send the content to a server. Every tool in this section runs in the page: JSON is parsed with the browser's own parser, hashes are computed with the Web Crypto API, JWTs are decoded by splitting and Base64-decoding the three segments locally. No request leaves the page, which you can verify in the browser's network tab.

What each tool handles

• JSON Formatter — pretty-print or minify, with the exact parse error position when the input is invalid.
• Base64 and URL Encode/Decode — UTF-8 aware, so accented characters and emoji round-trip correctly.
• JWT Decoder — shows header, payload and the expiry as a readable date; it does not verify the signature, and says so.
• Regex Tester — live matches with capture groups, with the flags the browser's RegExp engine supports.
• Hash Generator — SHA-1, SHA-256, SHA-384 and SHA-512 of text; MD5 is explained but not a Web Crypto algorithm.
• Timestamp Converter, UUID Generator, Number Base Converter, Color Converter, Color Picker and Diff Checker for the rest.

Standards followed

The tools follow the specifications they implement rather than a loose approximation: UUIDs are RFC 4122 version 4, JWTs are read as RFC 7519 describes, URL encoding uses the percent-encoding rules of RFC 3986 as implemented by encodeURIComponent, and Base64 follows RFC 4648. Each tool page notes the edge cases where the browser implementation differs from the letter of the standard.