SHAKE256 File Checksum Calculator
Compute the SHAKE256 hash of any file with a chosen output length, locally in your browser, and compare it with an expected checksum. No upload.
A multiple of 8, from 8 to 16384 bits.
No file selected yet. The checksum appears as soon as you pick a file.
The file is read in chunks inside your browser and is never uploaded.
What is SHAKE256 File Checksum?
This tool computes the SHAKE256 digest of a file with an output length you choose (default 512 bits) and checks it against an expected value. The file is processed in 4 MB chunks inside your browser.
How to use SHAKE256 File Checksum
- Set Output length (bits) first (multiple of 8, default 512); changing it later recomputes the hash.
- Click the drop zone or drag a file onto it; the file is read in chunks and a progress bar is shown.
- Check the File name and File size shown below to make sure you picked the right file.
- Paste the checksum published by the provider into Expected checksum — you get Match or Mismatch (case,
0xand a trailing file name are ignored). - Choose the Output format if you need uppercase hex or Base64, then click Copy.
Example
A file hash-abc.txt containing the 3 bytes "abc"
483366601360a8771c6863080cc4114d8db44530f8f1e1ee4f94ea37e78b5739d5a15bef186a5386c75744c0527e1faa9f8726e462a12a4feb06bd8801e751e4
Output length 512 bits.
When to use SHAKE256 File Checksum
Use it when a release or specification provides SHAKE256 checksums, or when you need a file fingerprint of a specific length. For ordinary download verification SHA-256 checksums are far more common.
How SHAKE256 File Checksum works
The file is read in 4 MB slices that are absorbed into the sponge one after another; the output is squeezed once the whole file has been read. SHAKE256 is an extendable-output function (XOF) from FIPS 202. It uses the same Keccak-f[1600] sponge as SHA-3 with a capacity of 512 bits (rate 1088 bits) and the domain suffix 1111 (padding byte 0x1F). After absorbing the input, the sponge is squeezed for as many bits as requested, so the output length is a parameter rather than a property of the algorithm. Shorter outputs are prefixes of longer ones. Security is min(output/2, 256) bits for collisions.
Common Use Cases
- Verify files whose integrity manifest uses SHAKE256
- Create a short (e.g. 128-bit) or long fingerprint of a file
- Cross-check an XOF implementation on real data
- Compare two large files without uploading them
Security Note
A checksum proves integrity only if the expected value comes from a trusted source. The file never leaves your device.
FAQs
Is the file uploaded?
No. The bytes are read with the File API and hashed in your browser.
Why does my checksum not match?
Check that both sides use the same output length: SHAKE256 with 256 and 512 bits give different strings (the shorter is a prefix of the longer).
Can I hash very large files?
Yes. Reading in chunks keeps memory use low; time depends on file size and device speed.