Test patterns, compare text, generate values
The Regex Tester runs JavaScript regular expressions against sample text with live match highlighting, so you watch a pattern’s behavior change as you edit it — much faster than the write, run, squint cycle. The Text Diff Checker compares two blocks of text line by line and highlights every difference, covering the everyday cases version control does not: two config files pulled from different servers, two API responses, or two drafts of the same paragraph that have quietly diverged.
Three generators handle randomness and hashing. The UUID Generator produces v4 identifiers one at a time or hundreds at once, drawn from the browser’s cryptographic random source. The Password Generator builds strong random passwords with custom length and character sets — and because generation happens on your device, the password has never existed anywhere else. The SHA Hash Generator computes SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text using the Web Crypto API, for checking a value against a published checksum or producing a stable cache key.
Decode JWTs without handing them to a server
The JWT Decoder splits a JSON Web Token into its header and payload, pretty-prints both, and checks the expiry claim — the first question in most authentication debugging sessions. This is the one tool in the category where client-side execution is not just convenient but necessary: a real access token grants access to something, and pasting it into a site that ships it to a server is handing that access away. Here the token is decoded by JavaScript in your browser and never transmitted, so inspecting a production JWT does not mean disclosing it.