SHA-256, SHA-384 and SHA-512 Hash Generator
Hash text or a file with the browser’s own cryptographic engine, and check it against a published checksum.
- Input
- Text · file
- Output
- Hex digest
- Processing
- In your browser
- Cost
- Free · no sign-up
Source
The digest covers the exact bytes, including a trailing newline. Text that looks the same but ends differently hashes differently.
Digest
HexCase and separators are ignored, so a value copied from shasum,certutil or a release page all compare correctly.
A hash is one-way. It is a fingerprint, not encryption — there is no key and no way back to the original.
Files are processed locally in your browser and are never uploaded to Nekhen.
About this tool
A cryptographic hash turns any amount of data into a fixed-length fingerprint. Change one byte of the input and the output changes completely, which is what makes it useful for checking that a file arrived intact.
A hash is one-way. There is no key and no way back: you cannot recover the original from the digest, and hashing is therefore not a way to protect or hide anything. "SHA-256 encryption" is a common phrase and a wrong one.
The three algorithms here come from the browser’s Web Crypto implementation — the same code that verifies certificates when you load a secure page. MD5 and SHA-1 are deliberately not offered: both have practical collisions, and neither should be used to establish that two files are the same.
Steps
How to use it
- Choose text or fileType into the box, or drop a file onto the target.
- Pick the algorithmSHA-256 unless something specific asked you for another.
- Read the digestIt is shown in groups of eight so it can be compared by eye.
- Verify if you have a published valuePaste the expected checksum and the tool says whether it matches.
Real situations
Common uses
- Checking that a downloaded installer or ISO matches the checksum on the project’s site
- Confirming that two copies of a file are byte-for-byte identical
- Producing a content fingerprint for a cache key or a deduplication list
- Reproducing a digest a colleague generated, to prove you are looking at the same data
Privacy
Files are processed locally in your browser and are never uploaded to Nekhen. Every calculation runs on your own device, so we never receive the contents of your file, never store it and never log it. Closing the tab clears everything from memory. More detail on the privacy page.
Common questions
Frequently asked
Can a hash be reversed?
No. A hash is designed to be one-way, and for these algorithms there is no known method of recovering the input. Short, guessable inputs — a common password, a single word — can still be found by trying candidates until one produces the same digest, which is why hashes alone are not a way to store passwords.
Is hashing the same as encryption?
No, and the difference matters. Encryption is two-way and needs a key: the point is to get the original back. Hashing is one-way and has no key: the point is a fingerprint. If you need to recover the data later, a hash is the wrong tool.
Why is MD5 or SHA-1 not offered?
Both are broken for this purpose: it is practical to construct two different files with the same MD5 or SHA-1 digest, so "the hashes match" no longer proves the contents match. Web Crypto does not implement MD5 at all, and offering either would mean shipping our own implementation of a hash nobody should rely on.
Is my file uploaded to check it?
No. The file is read from your own device and hashed in the browser. Nothing is transmitted, which is also why the size limit exists — the whole file has to fit in the tab’s memory at once.
Why does my digest differ from the one on the download page?
Usually the algorithm differs — a SHA-256 and a SHA-512 of the same file never agree. Otherwise the file itself differs: an interrupted download, a different version, or a file that was modified. The digest is the evidence, not the diagnosis.
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