Every developer has a set of small utilities they reach for daily — decoding a JWT, formatting JSON, generating UUIDs, testing regex patterns. Most of these tasks don't need a full IDE or installed software. So I built Filuni — a free, browser-based toolkit with 121+ tools across 12 categories. Here are my 10 favorites for developers: 1. JWT Decoder Paste a JWT token, instantly see the decoded header and payload. No more copy-pasting to jwt.io. Try it: filuni.com/filetool/dev/dev-jwt 2. JSON For