What is a cryptographic hash function?

A cryptographic hash function takes any input and produces a fixed-length digest. The same input always produces the same output, but even a single character change results in a completely different hash. Hashes are one-way — it is computationally infeasible to reverse them. They are used for data integrity verification, digital signatures, and checksums.

Is it safe to hash sensitive data here?

Yes. All hashing is performed 100% client-side in your browser using the Web Crypto API. Your text or file data never leaves your device — there are no API calls, no server-side processing, and no logging.

Why are MD5 and SHA-1 considered insecure?

MD5 and SHA-1 are vulnerable to collision attacks — it is feasible to find two different inputs that produce the same hash. SHA-1 collisions were demonstrated practically in 2017 (the SHAttered attack). Neither should be used for security-critical verification. Use SHA-256 or higher instead.

What is HMAC and when should I use it?

HMAC combines a hash function with a secret key to produce an authenticated hash. Unlike a plain hash, HMAC guarantees both integrity and authenticity. Use HMAC for API request signing, webhook verification, and JWT HS256/HS512 signature generation.

How does file hashing work?

When you drop or select a file, the browser reads it locally using the FileReader API. The hash is computed in-browser using crypto.subtle.digest() for SHA-family algorithms, or a pure TypeScript implementation for MD5 and BLAKE2b. Files are never uploaded to any server.

What is hash chaining and when is it useful?

Chain mode feeds each hash output back as the input for the next round, running 1–1000 iterations. This is useful for key derivation patterns, stress-testing algorithm performance, and demonstrating the avalanche effect across rounds.

Encoding & Data

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA3, and BLAKE2b hashes and HMAC from text or files instantly. Compare hashes, verify checksums, and chain hashes over multiple rounds. 100% client-side — your data never leaves your browser.

Open tool

Quick reference

Category: Encoding & Data
Runs in: Browser
Data stored: Nothing
Price: Free
Sign-up: Not needed

Browse categories

All features

8 algorithms: MD5, SHA-1, SHA-256/384/512, SHA3-256/512, BLAKE2b
HMAC generation for all SHA-family algorithms
Iterative hash chaining over 1–1000 rounds
Side-by-side hash comparison with character-level diff
Text and file input with drag-and-drop and clipboard paste
Hex, uppercase hex, and Base64 output formats

What you can do

Hash text instantly

Paste any text to compute MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA3, and BLAKE2b hashes simultaneously in hex or Base64 format.

Verify file integrity

Drag and drop a file to compute its checksum, then paste the expected hash to verify the file has not been corrupted or tampered with.

Generate HMAC signatures

Enter a secret key to produce HMAC-SHA-1, HMAC-SHA-256, HMAC-SHA-384, or HMAC-SHA-512 for API request signing, webhook verification, or JWT signatures.

Compare hashes side by side

Open the Verify tab to compare two hashes with character-level diff. The tool auto-detects the algorithm and flags mismatches.

Chain hashes iteratively

Use Chain mode to hash data over multiple rounds — each round feeds its output as the next input. Useful for key derivation and stress-testing hash performance.

Private by design

Client-side
No sign-up
Free

Hash Generator runs entirely in your browser tab. No data is uploaded, no server processes your input, and no account is required.

Specifications

Algorithms: MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA3-256, SHA3-512, BLAKE2b
HMAC: HMAC-SHA-1, HMAC-SHA-256, HMAC-SHA-384, HMAC-SHA-512
Chain mode: Iterative hashing, 1–1000 rounds
Output formats: Lowercase hex, uppercase hex, Base64
Input types: Text, file (drag-and-drop, clipboard paste)
Crypto engine: Web Crypto API + pure-TS MD5/BLAKE2b
Processing: 100% client-side, no upload