What this tool does
Calculate a local file’s SHA-256 and compare it with a value obtained from a trusted provider. The file stays in your browser.
How to use it
- Choose a file of at most 250 MiB (262,144,000 bytes).
- Optionally paste the provider’s expected SHA-256: exactly 64 hexadecimal characters.
- Generate the checksum, read the comparison status and copy the complete digest.
Formula and method
The browser reads the whole file into memory and uses Web Crypto SHA-256 to produce a 256-bit digest, displayed as 64 lowercase hexadecimal characters. Comparison ignores letter case and leading or trailing whitespace; other characters are not removed.
Example
A UTF-8 file containing only abc, without a byte-order mark or newline, has 3 bytes and SHA-256 ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad. Enter this full value to get a match; adding a newline changes the checksum.
Useful for
- Checking downloaded software archives
- Comparing exported files across devices
- Recording a stable content fingerprint
Limits and notes
A match means the calculated SHA-256 equals the expected value. It is not proof of publisher identity, a trustworthy reference, absence of malware or a valid digital signature. Hash collisions are possible. The whole file is read into memory; the 250 MiB input limit is not a memory-usage cap, and processing may fail on devices with little available memory.
Frequently asked questions
Is the selected file uploaded?
No. This tool reads and hashes the file inside your browser. File contents are not uploaded.
Which checksum types are supported?
SHA-256 only. It needs HTTPS and a browser with Web Crypto support. SHA-384, SHA-512, MD5 and SHA-1 are not offered.