What Is Hashing? SHA-256, JWTs and Developer Security Basics

Hashing turns any input into a fixed-length string of characters. Unlike encryption, it's one-way — you can't reverse a hash back to the original.

Why hashing matters

• Password storage — sites store the hash of your password, not the password itself.
• Integrity checks — a file's hash confirms it hasn't been tampered with.

Common algorithms include SHA-256 and SHA-512. The same input always produces the same hash, but even a tiny change produces a completely different one.

What about JWTs?

A JSON Web Token (JWT) is a compact, signed token used for authentication. It has a header, payload and signature, each Base64-encoded. Anyone can decode the payload — so never store secrets in it.

Free developer tools

Generate hashes with the Hash Generator (SHA-1/256/384/512), inspect tokens with the JWT Decoder, and encode data with the Base64 Encoder. Everything runs locally in your browser.