SHA256 File Checksum
Calculate a SHA-256 checksum or HMAC-SHA-256 value for a local file or URL content in your browser without uploading the local file. Expand to read more.
SHA-256 file checksum calculator
SHA-256 produces a 256-bit digest, normally displayed as 64 hexadecimal characters. This tool hashes a local file in your browser or hashes the bytes fetched from a URL. A local file is not uploaded to this site.
SHA-256 is part of the Secure Hash Standard defined by NIST FIPS 180-4. It is commonly used to publish download checksums and verify that a file has not changed since its expected digest was calculated.
How to verify a SHA-256 checksum
- Select a local file or switch to URL input.
- Use hexadecimal output when comparing with a conventional published checksum.
- Calculate the digest.
- Compare the entire result with the expected SHA-256 value from a trusted source.
The exact bytes matter. Repacking an archive, changing line endings, editing embedded metadata, or re-encoding an image produces a different hash even when the visible content appears unchanged.
Checksum versus authenticity
A matching SHA-256 value is useful only if the expected checksum is trustworthy. If an attacker can replace both a download and the checksum displayed beside it, an unkeyed hash does not establish who published the file. Signed releases or another authenticated distribution mechanism are needed when publisher identity matters.
Enable HMAC only when an existing workflow requires HMAC-SHA-256 and supplies a shared secret key. HMAC output is not the same as a plain file checksum.
SHA-256 file FAQ
Is SHA-256 better than MD5 for file verification?
SHA-256 is the appropriate choice when collision resistance matters. MD5 may still appear in legacy checksum lists, but it should not be selected for new security-sensitive uses.
Why does another SHA-256 tool return a different value?
Confirm that both tools received the same file bytes and use plain SHA-256 rather than HMAC-SHA-256. Also compare output formats: uppercase and lowercase hexadecimal represent the same value, while Base64 looks different.
How do I hash text instead of a file?
Use the SHA-256 text tool to choose a text input encoding before calculating the digest.
