File Hash Calculator checksum
Compute MD5, SHA-1, and SHA-256 for a local file entirely in the browser. The file is never uploaded.
What this tool does
Confirming that a downloaded file matches what the publisher released means comparing hash values. This tool reads a file you select through the browser File API and computes MD5, SHA-1, and SHA-256 in one pass.
The important property is that the file goes nowhere. Many online hash services upload the file to a server for processing, which is equivalent to sending an internal document or installer to a third party. Here the contents are read only into browser memory, the SHA digests come from the built-in Web Crypto API, and MD5 comes from crypto-js.
Paste a published checksum into the comparison field and the tool reports whether any of the three computed values matches. Comparison ignores letter case.
When to use it
Use it to verify an installer or release archive against a published checksum, to confirm that two files are genuinely identical, to check a backup against its source, or to make sure you and a colleague are looking at the same file.
Input and output examples
Select a downloaded installer
MD5, SHA-1, and SHA-256 digests
The file is read locally and never uploaded.
Paste the published SHA-256 into the compare field
Match or mismatch indication
A match against any of the three computed hashes is reported.
Notes and limitations
The whole file is read into memory, so very large files slow the browser down; this tool refuses files above 200 MB. A mismatch means the download was damaged or is a different build. Bear in mind that a match only proves the file corresponds to that checksum, so the checksum itself must come from a trustworthy source such as an official HTTPS page or a signed release. MD5 and SHA-1 are vulnerable to deliberate forgery, so compare the SHA-256 value when security matters.
Frequently asked questions
Is the file sent to a server?
No. It is read through the File API inside the browser and no network request is made.
The checksum does not match.
The download may be incomplete or a different version. Download again, and if it still differs check that the published checksum page is current.
Which hash should I compare?
Whichever the publisher provides. When you can choose, SHA-256 is the safest.