Hash Generator

Frequently Asked Questions

Why is MD5 not available?

MD5 is intentionally omitted because the browser Web Crypto API does not provide it, and it is cryptographically broken and unsafe for security use.

Which hash algorithm should I use?

SHA-256 is a solid default for integrity checks. SHA-384 and SHA-512 produce longer digests; SHA-1 is included for legacy compatibility only.

Can I reverse a hash back into the original text?

No. Cryptographic hashing is one-way by design. The same input always gives the same digest, but a digest cannot be turned back into the input.

Does my text get uploaded?

No. Hashing runs entirely on your device using the browser Web Crypto API, so your text never leaves the browser.

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Estimates for informational purposes only.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.

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How This Calculator Works

A cryptographic hash turns any text into a fixed-length string of hexadecimal characters called a digest. The same input always produces the same digest, but even a one-character change produces a completely different one, and you cannot reverse a digest back into the original text. Type or paste your text, pick an algorithm, and click Generate to see the hash.

How It Works

The text is encoded to UTF-8 bytes and passed to the browser's built-in Web Crypto API using crypto.subtle.digest. The raw bytes that come back are then encoded as a lowercase hexadecimal string. SHA-1 produces 40 hex characters, SHA-256 produces 64, SHA-384 produces 96, and SHA-512 produces 128. Everything runs locally, so your text is never uploaded.

Worked Example

Hashing the text "hello" with SHA-256 gives 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824. Change it to "Hello" with a capital H and the digest becomes entirely different, even though only one letter changed. This sensitivity is what makes hashes useful for verifying that data has not been altered.

Common Mistakes

Expecting to decode a hash back to the original text; hashing is one-way by design.

Using a fast hash like SHA-256 alone to store passwords; use a slow, salted password hash such as bcrypt or Argon2 for that.

Comparing hashes generated with different character encodings, which will not match.

Looking for MD5 here. It is intentionally omitted, see the FAQ below.

Tips & FAQ

Where is MD5? MD5 is intentionally omitted because the browser Web Crypto API does not provide it, and it is cryptographically broken and unsafe for security use.

Which algorithm should I use? For general integrity checks SHA-256 is a solid default. SHA-384 and SHA-512 give longer digests; SHA-1 is included for legacy compatibility only.

Is SHA-1 safe? SHA-1 is deprecated for security purposes because practical collisions exist; avoid it for signatures or certificates.

Does my text leave the browser? No. Hashing happens entirely on your device using the Web Crypto API.

Frequently Asked Questions

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