Debugging Utilities That Never See Your Data
Pasting a JWT, an API payload or a production hash into a random website is a quiet security risk. Every tool in this hub formats, encodes, decodes and hashes entirely inside your browser using the Web Crypto and standard JavaScript APIs, so tokens and secrets are never transmitted. They are built to be fast enough to replace the one-off scripts you would otherwise write.
Why use SmartToolPack Developer & Code Utilities?
🔐 Secrets stay local
JWT decoding, hashing and Base64 conversion run client-side. Nothing is logged or stored.
⚡ Instant, keyboard-friendly
Results update as you type, with one-click copy and keyboard shortcuts on the most used tools.
🧰 Covers the daily basics
JSON, Base64, URL encoding, UUIDs, Unix timestamps, hashes, regex, SQL and cron in one place.
📱 Works on any device
No extension or install. Open a tool on your phone when you are away from your editor.
Frequently asked questions
Can the JWT decoder verify a token signature?
It decodes the header and payload so you can inspect claims and expiry. Signature verification needs the signing secret or public key, which you should never paste into a website.
Which hash algorithms are supported?
SHA-1, SHA-256 and SHA-512 via the Web Crypto API. Use SHA-256 or stronger for anything security related; SHA-1 is provided for checksums and legacy comparisons.