Checksum Calculator Online – MD5, SHA-256, CRC32 of a File

How to use the Checksum Calculator

Type or paste text into the input box, or switch the source to File and choose a file — it is hashed locally, never uploaded.

Pick the Main algorithm you want to verify; every other common checksum of the same data is listed below it.

To verify a value, paste it into Compare with an expected hash — the tool reports a match, or which algorithm it matches instead. Copy any row with its Copy button.

Checksum calculator for files and text

A checksum is a short fingerprint of data. If even one bit of a file changes, its checksum changes too. This checksum calculator shows the algorithm you pick at the top and lists more than fifteen other common checksums and hashes of the same file or text below it, so you can match whatever value a download page, a colleague or a backup system gives you — without having to know in advance which algorithm they used.

Example

A selection of checksums of the 10-byte text Verify me!:

CRC-32      2f9ed341
Adler-32    14d50389
MD5         9ff4e9241d48f36fed16a72817d4380a
SHA-1       e7e9bf1a7a9f9d463ec7f6a70786a8a47baa6634
SHA-256     76c83ce23a60b7a938cc9fd96138a0f0f5adf51319bfea0858e8f4b47d78758a
SHA-512     3542da57d3a4f43b51060b1e365d72925de2f92a488ca9780435a38df666c6d45d4928e2c3b3e38957ad5b1bbb94d4f4acee828d8f3ff10bf26d70cab0e74375
SHA3-256    079c0ff51ae14b0bfaca5aa4033c2bee06e8e2bbcff0b57f20dbb1fe564993b0
BLAKE2b     be9c891b3e0a2fb49df8efa08b37e76f1e92d086b4326a59e3b6faef800c1b6b8f325a38108890f6422b247f183918092ac776a99ca3a31bf13382e14dc65533
BLAKE3      db868030702cbbf590bafa0ddb0e753deadebbf195b1e78493af3989c890e5b1
xxHash64    a03874f5898499db

Each row has its own Copy button, and the Compare field below tells you instantly whether a pasted value matches — or which other algorithm it matches if you picked the wrong one.

How to verify a download

Find the checksum on the official download page or release notes, and note the algorithm (usually SHA-256).
Upload the downloaded file here. It is read locally; nothing is uploaded to a server.
Paste the published value into Compare with an expected hash. Case does not matter; the tool reports a match or a mismatch.

A match means your copy is identical to the file the publisher hashed. A mismatch usually means an incomplete or corrupted download — download it again from the official source.

Checksums vs cryptographic hashes

Type	Algorithms here	Detects accidents	Detects tampering
Checksum	CRC-32, Adler-32, xxHash64	Yes	No — easy to forge
Broken hash	MD5, SHA-1	Yes	Not reliably — collisions are practical
Secure hash	SHA-256, SHA-512, SHA3-256, BLAKE2b, BLAKE3	Yes	Yes, if the expected value comes from a trusted source

That last condition matters: if an attacker can change the file on a website, they can often change the checksum next to it too. Checksums prove integrity, not authenticity. For that, publishers sign releases (for example with GPG, Sigstore or code-signing certificates), and you should verify the signature where one is offered.

Command-line equivalents

Linux: sha256sum file, md5sum file. macOS: shasum -a 256 file, md5 file. Windows PowerShell: Get-FileHash file (SHA-256 by default) or certutil -hashfile file SHA256. This tool gives the same results and is convenient when you are not at a terminal.

For a single algorithm with more options, see the SHA-256, MD5 or CRC-32 tools. Very large files are processed in your browser’s memory, so multi-gigabyte files may be slow on low-memory devices.

Frequently asked questions

Which checksum should I use to verify a download?

Use whichever algorithm the publisher lists — ideally SHA-256 or stronger. Compare the value exactly, character by character.

Is my file uploaded when I calculate a checksum?

No. The file is read and hashed in your browser. Nothing is sent to a server.

What does it mean if the checksum does not match?

The file differs from the one the publisher hashed — usually because the download was incomplete or corrupted. Download it again from the official source.

Does a matching checksum prove the file is safe?

It proves the file matches the published value. If the checksum itself could have been altered, also verify the publisher’s digital signature.

Why are MD5 and SHA-1 still listed?

Many older download pages and systems still publish them, and they remain useful for detecting accidental corruption. They should not be relied on against deliberate tampering.

Checksum Calculator