SHA Checksum
This checksum calculator computes SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or of a file in one step, using your browser's built-in Web Crypto API.
About this tool
This checksum calculator computes SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or of a file in one step, using your browser's built-in Web Crypto API.
How to use it
- Choose Text or File.
- Type or paste text, or drag and drop a file (or browse for one).
- Click Compute Checksums.
- Compare the result with the checksum published by the file's source.
Good to know
- SHA-256 produces a 256-bit hash, shown as 64 hexadecimal characters; SHA-512 produces 128.
- Changing even one byte of the input produces a completely different hash.
- SHA-1 is considered broken for collision resistance and should not be used for security; prefer SHA-256 or stronger.
- Hashes are computed with crypto.subtle.digest locally, so large files are hashed without uploading.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
How do I verify a downloaded file?
Hash the file here with SHA-256 and compare the result to the checksum on the download page. If they match exactly, the file has not been altered.
Is my file uploaded to calculate the hash?
No. The file is read and hashed in your browser; it never leaves your device.
Which algorithm should I use?
SHA-256 is the most common choice for verifying downloads and integrity. Use SHA-1 only when an older system requires it.
Can a hash be reversed to get the original data?
No. SHA hashes are one-way functions. Short or common inputs can still be guessed, which is why passwords need salted, slow hashing instead.