FAQ
How is SHA different from MD5?
SHA digests are longer and have no practical collisions today, while MD5 collisions were demonstrated back in 2004. Use SHA-256 or above when tamper resistance matters.
Should I use SHA-256 or SHA-512?
SHA-256 is enough for most cases: 64 characters of output and fast. SHA-512 is longer and slower with little practical gain for ordinary checksums.
Is the result uploaded?
No. It is computed locally with the browser Web Crypto API and works offline.
About this tool
One page, four digests: MD5, SHA-1, SHA-256 and SHA-512, switched from the dropdown and recomputed instantly. Text and files both work (Hash a file in the toolbar) and everything runs in the browser.
Output lengths differ: 32 hex characters for MD5, 40 for SHA-1, 64 for SHA-256, 128 for SHA-512. The length identifies the algorithm, so counting digits first resolves most "checksum mismatch" confusion.
SHA-1 should no longer be used: the 2017 SHAttered attack produced two different PDFs sharing one SHA-1 digest, and the cost keeps falling. GitHub and every major distribution stopped publishing SHA-1 sums years ago. For integrity checks use SHA-256 - standard length, fast, and what release pages actually list.
SHA-512 is not simply "a more secure SHA-256". On 64-bit hardware it is often faster, but the digest is twice as long, so storage and transfer cost more. For ordinary file verification SHA-256 is enough; raw strength is not the bottleneck here.
One practical caveat: SHA goes through the browser Web Crypto API, which only exists in a secure context (https or localhost). If you save this page and open it over file://, SHA may fail while MD5 still works, because MD5 here is a pure-JavaScript implementation that does not depend on that API.