I built KeptTools so your JWT, SQL, and Base64 never leave the browser Most “free online tools” are convenient until you paste something you shouldn’t. A JWT from staging. A SQL dump with real emails. A Base64 string that still holds a secret. If that page uploads your paste, you’ve already shared more than you meant to. The problem I kept needing small utilities: format / validate JSON format SQL decode a JWT encode / decode Base64 generate hashes ...