What is a checksum?
A checksum is a short value calculated from a file or block of data. If the file changes, the checksum usually changes too, which makes it useful for file validation.
ALT File Checksum Verifier
Drag and drop files to instantly calculate MD5, SHA-1, and SHA-256 checksums. Verification runs locally in your browser so files are never uploaded to any server.
ALT File Checksum Verifier works as a checksum calculator and validation tool for downloaded files, archives, installers, and shared documents. Paste the expected checksum if you have one, then choose your file to compare MD5, SHA-1, and SHA-256 values. This is useful when a download page gives you a checksum and you want to confirm the file arrived unchanged.
Drop files here or click to browse
All processing is offline. No file size limits, but very large files may take a moment.
Checksum Questions
What does a checksum calculator do?
A checksum calculator reads a file and generates hash values such as MD5, SHA-1, or SHA-256. You can compare the result with a checksum from a download page or vendor.
How do I verify a file checksum?
Paste the expected checksum into the verifier, then choose the file. If the calculated hash matches the expected value, the file passed that checksum check.
What is a checksum error?
A checksum error means the calculated value does not match the expected value. The file may be incomplete, changed, corrupted, or different from the file the checksum was made for.
How do I check a checksum on Linux?
On Linux, common commands include md5sum, sha1sum, and sha256sum. This browser tool gives you a visual alternative when you want to check a file without using the terminal.