File Hash Calculator
Calculate a SHA-256 checksum for a file selected in your browser.
Try a fictional file
Try a fictional file
Compare exact file bytes with SHA-256.
These small practice files are generated locally from fictional data. Download one, then select it yourself in the existing tool. Nothing is selected, run, cleared or replaced automatically. Processing stays in your browser; loading this page and its practice files still requests site assets.
Download practice file (sample.txt)What to do
Select sample.txt and calculate SHA-256. Compare the entire digest below.
How to read the result
The digest must match exactly; changing the filename does not change it. Matching hashes do not prove a trusted source.
SHA-256: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Keep your original. Open the downloaded result and check it before sharing. If your browser cannot process this format, use this walkthrough; no result is guaranteed.
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Only the tool’s public link is shared. Your inputs and results stay here.
Show link to copy manually
Quick answer
Select a file to calculate its SHA-256 checksum in this browser. The filename and size appear separately for identification; the result and Copy hash button contain only the digest. SHA-256 hashes file bytes, not the filename.
The page and its assets load from the site; this operation uses your entered values only in this browser and does not send them to a calculation endpoint.
How to use it
Select a file and calculate its SHA-256 checksum. The filename and size are shown separately; Copy hash copies only the digest so you can compare it with a trusted reference.
Limits
Web Crypto reads the entire file into memory for this calculation, so very large files may exceed available browser memory. A matching SHA-256 digest compares file bytes; it does not prove who created a file or whether it is safe to open.
Frequently asked questions
Does calculating a checksum upload the file?
The hash is calculated in the browser after you select the file. The page itself still loads code and assets from the site.
Does the filename affect the checksum?
No. SHA-256 is calculated from the file bytes, not its name. Two files with identical bytes have the same digest even if their names differ.
What does Copy hash copy?
It copies only the SHA-256 digest, without the filename or size, so you can paste the value into a checksum comparison.
What does a matching SHA-256 checksum show?
It shows that the compared byte sequences produce the same digest, which is useful for integrity checks. It does not prove the source is trustworthy.
Can the tool hash a very large file?
The Web Crypto digest API does not support streaming input; this tool reads the whole file into memory. Very large files may exceed the browser’s available memory.
Further guidance
Sources and references
These references document the cited standard or browser API; they do not validate the tool’s output.