What's a hash and what is it for?

A hash function takes input of any length and returns a fixed-length fingerprint. Two different inputs almost never produce the same hash (a 'collision'). Use cases: verifying that a downloaded file is not corrupted (compare hashes), storing passwords without storing the password itself, generating compact signatures for integrity checks.

Which algorithm should I pick?

For file-integrity checksums where the source is trusted, MD5 or SHA-1 are fast and fine (`*.md5`, `*.sha1` files everywhere). For anything security-sensitive (password hashing, signatures, blockchain), use SHA-256, SHA-512, or SHA-3. CRC32 is NOT a cryptographic hash. It detects accidental bit-flips (zip files, ethernet frames) and does not defend against intentional tampering.

Are MD5 and SHA-1 really broken?

Yes for cryptographic purposes. Researchers have produced practical collisions: two different files that hash to the same MD5 or SHA-1. An attacker can substitute one file for another without changing the published hash. For non-adversarial integrity checking (download did not corrupt in transit) they remain useful. Just do not rely on them when an adversary is in the threat model.

Where is the hash computed?

On the packet.guru server, using Node's `crypto` module (CRC32 uses the `crc-32` package). The text you submit goes over HTTPS, gets hashed, and the result comes back. Max input is 50 KB per request. If you need everything to stay inside your browser, use the SubtleCrypto API in DevTools.

Why are MD5 and SHA-1 still in the list if they are broken?

Plenty of legitimate tasks still need them: verifying a checksum from an older project's release notes, matching the hash of a third-party-supplied file, learning. The tool keeps them with the security caveat above so you do not pick the wrong one for a sensitive context.

Free, no signup, rate-limited per IP. Max input 50 KB per request.

WEB

Hash Generator

Generate MD5, SHA256, etc.

Input

Text to Hash

Algorithm

Create cryptographic hashes (digital fingerprints) for any text. Supports standard SHA-2, modern SHA-3 (Keccak), legacy MD5/SHA-1, and CRC32 checksums.

Terminal

Console ready. Execute a command to see output...

About Hash Generator

One-Way Logic

A hash function takes input data and turns it into a fixed-length string of characters. It is a one-way process; you cannot turn the hash back into the text.

Use Cases

Integrity: Verifying that a downloaded file hasn't been corrupted.
Passwords: Storing passwords securely (often with "salt").
Signatures: Digital proof of content.

Algorithm Safety & Use Cases

MD5/SHA-1: Legacies of the past. Fast but cryptographically broken (collision prone). Use only for non-security checksums.
SHA-2 (256/384/512): The industry standard. Used by Bitcoin, SSL, and US Government.
SHA-3 (Keccak): The new frontier. Resistant to length-extension attacks found in SHA-2.
RIPEMD-160: The short-hash choice for Bitcoin addresses.
CRC32: Not crypto! Used for detecting accidental file corruption (zip files, ethernet packets). Fast detection of bit-flips.

How to use Hash Generator

Paste the text
Type or paste up to 50 KB of text. Hashes are computed over the exact input bytes including whitespace, so no extra trimming happens.
Pick an algorithm
MD5 default is fine for integrity checksums. Use SHA-256, SHA-512, or SHA-3 for security-sensitive contexts. CRC32 only for non-adversarial bit-flip detection.
Hit Generate Hash
The hash is computed on the packet.guru server and returned as a lowercase hex string (CRC32 is hex too).
Compare or copy
Copy the hash and compare it against an expected value to verify integrity, or paste it into your application.

Frequently Asked Questions

: A hash function takes input of any length and returns a fixed-length fingerprint. Two different inputs almost never produce the same hash (a 'collision'). Use cases: verifying that a downloaded file is not corrupted (compare hashes), storing passwords without storing the password itself, generating compact signatures for integrity checks.
: For file-integrity checksums where the source is trusted, MD5 or SHA-1 are fast and fine (*.md5, *.sha1 files everywhere). For anything security-sensitive (password hashing, signatures, blockchain), use SHA-256, SHA-512, or SHA-3. CRC32 is NOT a cryptographic hash. It detects accidental bit-flips (zip files, ethernet frames) and does not defend against intentional tampering.
: Yes for cryptographic purposes. Researchers have produced practical collisions: two different files that hash to the same MD5 or SHA-1. An attacker can substitute one file for another without changing the published hash. For non-adversarial integrity checking (download did not corrupt in transit) they remain useful. Just do not rely on them when an adversary is in the threat model.
: On the packet.guru server, using Node's crypto module (CRC32 uses the crc-32 package). The text you submit goes over HTTPS, gets hashed, and the result comes back. Max input is 50 KB per request. If you need everything to stay inside your browser, use the SubtleCrypto API in DevTools.
: Plenty of legitimate tasks still need them: verifying a checksum from an older project's release notes, matching the hash of a third-party-supplied file, learning. The tool keeps them with the security caveat above so you do not pick the wrong one for a sensitive context.
: Free, no signup, rate-limited per IP. Max input 50 KB per request.