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File Checksum Calculator (MD5, SHA-256)

Work out the MD5, SHA-1, SHA-256, SHA-384 or SHA-512 checksum of a file and compare it with the one you were given.

File checksum
Choose a file. It is read in this page and never leaves your device.

The file is read by your browser. It is not uploaded and not saved.

Paste the value the publisher lists.

Choose a file. It is read inside this page and is never uploaded.

Result
Checksum

File size
File name

Private: Everything runs in this page. Nothing you type is sent anywhere or saved.

Updated

On this page
  1. Checksums of small files
  2. Formula
  3. How the file checksum works
  4. What this tool does not do
  5. Frequently asked questions
  6. References
  7. Related tools

Checksums of small files

File contentSizeMD5SHA-256
(empty file)0 bytesd41d8cd98f00b204e9800998ecf8427ee3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
"abc"3 bytes900150983cd24fb0d6963f7d28e17f72ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
"hello\n"6 bytesb1946ac92492d2347c6235b4d26111845891b5b522d5df086d0ff0b110fbd9d21bb4fc7163af34d08286a2e846f6be03

Formula

checksum = hash function applied to every byte of the file

How the file checksum works

  1. Step oneChoose a file with the button. It is read inside this page, not uploaded.
  2. Step twoPick the checksum type that the publisher lists (SHA-256 is the most common today).
  3. Step threePaste the published checksum in the comparison box. The page says Match or No match; two equal checksums mean the file is the same, bit for bit.

What this tool does not do

  • It cannot tell you whether a file is safe or free of viruses; it only says whether two checksums are equal.
  • A checksum you copy from the same page as the download can be changed together with the file, so take it from a source you trust.
  • It reads one file at a time and does not check folders.

Frequently asked questions

Is my file uploaded?

No. Your browser reads the file on your own device and works out the checksum there. Nothing is sent anywhere or saved.

How large a file can it handle?

The file is read into memory, so the limit is your browser's memory, roughly 2 GB, and large files take a while. If the browser runs out of memory the tool shows a message.

What does it mean when the checksums match?

The file is identical to the one the checksum was made from. It does not prove the file is safe: the publisher's checksum has to come from a place you trust.

References