SHA-256 checksum
Get the SHA-256 checksum of one or more files. A checksum is a fingerprint of a file: if even one byte changes, the checksum changes completely. Use it to check that a download is complete and has not been altered, or to record a fingerprint of your own files.
Your files stay on your device. They are processed in your browser and not uploaded.
How to use it
- Drop one or more files on the box above, paste them, or choose them from your device.
- Wait while each file is read and its checksum is calculated.
- Copy a checksum, or download all of them as a .sha256 file.
Questions and answers
What is a SHA-256 checksum?
It is a 64-character fingerprint calculated from the contents of a file. Changing even one byte gives a completely different checksum, which makes it useful for spotting incomplete or modified files.
Is my file uploaded?
No. Your browser reads the file and calculates the checksum on your device. The file is not uploaded.
Is there a file size limit?
Files up to 2 GB are accepted. The whole file is read into memory, so very large files can be slow or fail on devices with little memory.
Can I check several files at once?
Yes. Add several files and each one gets its own checksum. You can download the results as a .sha256 file in the format used by the sha256sum command.
Does it support MD5 or SHA-1?
Not at the moment. This tool only calculates SHA-256 checksums.