Hashes explained — and verified in seconds
A hash function turns any input into a fixed-length fingerprint. Same input, same fingerprint, always; change one bit and the output is unrecognizable. That is how download sites prove a file arrived intact: they publish the SHA-256, you hash what you got, and the two strings either match or they do not.
Not all hashes are equal. MD5 and SHA-1 are cryptographically broken — collisions can be manufactured — but they still work as accidental-corruption checksums. SHA-256 and SHA-512 are the modern defaults for anything security-relevant. Computing all five at once means never caring which one the site published.
Open the free Hash Calculator — no signup, runs entirely in your browser.
How to use it
- Paste text, or drop the file you want to hash.
- All five digests — MD5, SHA-1, SHA-256, SHA-384, SHA-512 — compute in one pass.
- Compare the relevant algorithm's output against the published checksum.
Why this one
- Five algorithms in a single pass — no re-hashing per algorithm.
- Text and file input, hashed locally at full speed.
- Nothing is uploaded; hashing runs entirely in your browser.
- Hex output ready to compare against published checksums.
Frequently asked questions
Is MD5 still safe to use?
Not for security: researchers can craft two different files with the same MD5. For detecting accidental corruption during downloads it is still serviceable, but for integrity against tampering use SHA-256 or better.
Can a hash be reversed to get the original data?
No. Hashing is one-way by design. Attackers can only guess inputs and compare hashes — which is exactly why passwords need slow, salted password-hashing functions instead of raw SHA.
Why do two files sometimes show the same MD5?
That is a collision. For MD5 and SHA-1 they can be constructed deliberately; for SHA-256 none are known. Matching checksums from a trusted source still confirm your download, but the trust comes from the source, not the algorithm.