Which algorithms are suitable for security purposes?

For security-sensitive tasks such as verifying file integrity or digital signatures, use SHA-256 or SHA-512. MD5 and SHA-1 are cryptographically broken and should not be used for security. CRC32 and FNV-1a are non-cryptographic checksums intended only for fast data lookup and error detection.

Is my data sent to a server?

No. MD5, CRC32, and FNV-1a are pure JavaScript implementations running entirely in your browser. SHA-1, SHA-256, SHA-384, and SHA-512 use the browser's built-in Web Crypto API — also fully local. No text is transmitted anywhere.

What is a hash collision?

A hash collision occurs when two different strings produce the same hash output. This is theoretically possible with any hash function. Use Compare mode to check whether two strings collide for a given algorithm.

What is FNV-1a used for?

FNV-1a (Fowler–Noll–Vo) is a fast, non-cryptographic hash used in hash tables, caches, and bloom filters. It is not suitable for security but excels at distributing keys uniformly with minimal computation.

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String Hash Tools

Hash strings with MD5, SHA-1, SHA-256, SHA-512, CRC32, and FNV-1a

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このツールについて

Generate cryptographic and non-cryptographic hashes for any text string using six algorithms: MD5 and CRC32 (pure JavaScript implementations); SHA-1, SHA-256, SHA-384, and SHA-512 (via the built-in Web Crypto API); and FNV-1a 32-bit (pure JavaScript). All hashes are computed instantly in your browser — nothing leaves your device. Switch between hexadecimal and Base64 output formats with one click. Enable Compare mode to check whether two strings produce the same hash for any algorithm — useful for verifying file integrity or understanding hash collisions.

使い方

1 Type or paste your string into the input field.
2 All six hash outputs update automatically as you type.
3 Click 'HEX' or 'Base64' to switch the output encoding.
4 Click any hash value to copy it to your clipboard.
5 Toggle 'Compare Mode' and enter a second string to check whether both produce the same hashes.

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