What is a checksum used for?

A checksum is used to detect whether content changed. If two files or text blocks produce the same checksum with the same algorithm, they are likely identical. If the values differ, the content changed or was corrupted.

Can I calculate a checksum for a local file without uploading it?

Yes. The file is processed locally in your browser, so the contents do not leave your device.

Which checksum algorithm should I use?

SHA-256 is the usual default for modern release verification. Use SHA-384 or SHA-512 when required by your workflow, and only use SHA-1 for legacy compatibility.

Why does the expected checksum not match?

The most common reasons are using the wrong algorithm, comparing the wrong encoding, hashing a different file, or dealing with corrupted or modified content.

Is this the same as an HMAC?

No. A checksum is an unkeyed digest for integrity checking, while HMAC uses a secret key and is meant for authenticity verification between parties sharing that secret.

Checksum Calculator

Calculate SHA checksums for pasted text or local files with optional expected-value verification and hex or Base64 output. Perfect for release verification, integrity checks, file-transfer debugging, and deployment workflows.

checksum

sha256

hash

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Quick Presets

Examples for checksum calculator workflows

Calculate Checksum Settings

Hash text or a local file and compare the result with an expected checksum when you need a quick integrity check.

Checksum Source

Input

Characters: 0

Lines: 0

Bytes: 0

Digest Algorithm

SHA-1Legacy compatibility only; avoid for new security useSHA-256Recommended default for most integrity checks and HMACsSHA-384Longer digest with moderate size increaseSHA-512Largest digest size with strong collision resistance

Output Encoding

HexMost common format for checksums and CLI verificationBase64Compact text form often used in APIs and headers

Expected Checksum (Optional)

How it works: This tool hashes either text or a local file using the selected SHA algorithm, then optionally compares the result with an expected checksum. Use it for integrity checks, release verification, and debugging file-transfer mismatches.

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