File SHA-256 checksum
Compute a file SHA-256 checksum locally without uploading it.
Private: it runs in your browser and what you type is never sent anywhere. How to check it
Computed over every file byte without uploading it.
Your files are processed here, on your device
We do not send the contents of your files or text to any server: everything is processed in your browser’s memory. No account is needed, there is no daily quota and we use no analytics or trackers. Each tool has size limits to protect your device’s memory.
A connection is only needed to load the site. After that you can disconnect and the tools keep working (some previews may need the connection). Hosting may receive technical visit data. Favorites store only tool identifiers in this browser.
How we handle your data →How to use this tool
- Select a file up to 100 MiB.
- Compute SHA-256 and wait for the complete checksum.
- Compare all 64 digits with a trusted reference, then copy or download.
An example you can verify
Check a three-byte file against a known reference checksum.
Example input
File containing hexadecimal bytes 61 62 63: abc, without a trailing newline.
Expected result
ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Try these files containing fictitious data:
Download sample · sha256-abc.txtIf an editor adds a newline, the file contains different bytes and has a different checksum. Renaming it does not change this checksum.
File SHA-256 checksum: uses and practical guidance
A SHA-256 checksum represents file bytes as a string of sixty-four hexadecimal digits. It helps determine whether a copy matches a reference computed over the same content. Filename, extension and filesystem date do not enter the calculation, so renaming alone preserves the checksum. Changing bytes, even through one line ending or metadata stored inside the file, normally produces a different checksum. The tool reads bytes without opening the file as a document or interpreting its format. This distinction makes checksum comparison useful even when two files look similar in their ordinary viewers.
The reference matters as much as the calculation. Matching a checksum published by a trusted source checks integrity relative to that reference. It does not independently identify the author or certify safety. A harmful file also has a valid SHA-256 checksum. This page does not query malware databases, verify digital signatures or replace the originating service's download-authentication procedures. Compare the entire string instead of only its first characters, and confirm that the reference belongs to the same file and version. A mismatch establishes different bytes rather than explaining which change occurred or whether it was intentional.
Text files require attention to exact bytes. Editors may store the same visible text with different encodings, initial markers or line endings. The abc example contains three bytes and no trailing newline. If an editor appends one, the checksum correctly changes. Resaving an image or PDF can likewise change metadata or compression while preserving a similar appearance. The text SHA-256 tool and this file tool can match only when file bytes correspond exactly to the encoding used by the text operation. Retain the original file when exact comparisons are needed instead of assuming a resaved copy preserves its checksum.
Calculation runs in the browser and requires HTTPS or a secure local environment with cryptography available. Files up to one hundred MiB, or 104,857,600 bytes, are supported. The browser loads content into memory for this operation, so use smaller files on devices with limited resources. An empty file is valid and has a defined checksum too. Wait for calculation to finish before copying or downloading the string. Retain the filename and source reference alongside it to avoid comparing the wrong versions later. Selecting another file or resetting removes the old result from the active download controls rather than keeping a stale checksum ready for accidental reuse.
Settings and limits
Select a file up to 100 MiB. The browser computes SHA-256 over its exact bytes and displays 64 hexadecimal digits. The filename is not part of the calculation. Content is not opened and no malware database is queried. This function requires HTTPS or a secure local environment.
Frequently asked questions
Does the checksum confirm the file is safe?
No. It compares integrity against a trusted reference. A checksum alone does not identify the author or certify content safety.
Is it free, and do I need to sign up?
Yes, it is free. You do not need to sign up, create an account or install an app, and there is no daily quota: open the tool and use it. The only limits are file sizes, which protect your device’s memory.
Is my data sent to any server?
No. What you type or paste is processed in your browser’s memory and is not sent to any server. You can check it in the browser’s Network tab or by going offline after the page has loaded.