What this tool does
The tool reads the selected file bytes locally and uses the Web Crypto API to calculate a SHA-256 checksum.
Use this page when you need to calculate a SHA-256 checksum for a local file and compare it with a trusted value from the software publisher or file provider.
Best uses
Useful for
Verifying downloaded software against a published SHA-256 checksum.
Useful for
Checking whether two local files are byte-for-byte identical.
Useful for
Documenting file integrity for your own workflow without uploading the file.
Useful for
Learning what a checksum can and cannot prove.
How to use
- Select a file from your device.
- Wait for the local hash calculation.
- Copy the SHA-256 value.
- Optionally paste an expected hash to compare.
Privacy and local processing
Local workflow
- Select the file you want to verify.
- Let the browser read the file and calculate the SHA-256 digest locally.
- Copy the result and compare it exactly with the trusted published checksum.
- Download again from the official source if the values do not match.
Before sharing the output
- Compare every character; one changed byte produces a different hash.
- Use the checksum from the official publisher, not a random forum or mirror.
- Remember that a matching hash proves byte identity, not file safety.
- Do not publish hashes of private files if exact-file matching would be sensitive.
Supported files and limitations
Supported: Any file your browser can read locally.
- A hash proves byte equality; it does not prove a file is safe.
- This is not a malware scanner.
- Very large files may take longer and require memory depending on the browser.
Checksum verification vs virus scanning
A checksum tells you whether bytes match an expected value. It does not tell you whether those bytes are safe. For software downloads, compare the hash with the official source and still use normal security checks.
Common mistakes to avoid
- Do not treat SHA-256 as a malware scan.
- Do not trust a checksum from the same untrusted place as a suspicious download.
- Do not upload private files to a checksum website when local hashing is enough.
- Do not share the selected file or its private filename in support messages.
FAQ
What is SHA-256 used for?
It is commonly used to verify that file bytes match an expected value.
Does this scan for viruses?
No. It calculates a checksum only.
Can I compare an expected hash?
Yes. Paste an expected hash into the compare field after calculation.
Is the file uploaded?
No. The hash is calculated locally.
Why is the hash different?
Any byte change, including metadata or line endings, changes the SHA-256 digest.
Related privacy guides
What is a file checksum?
Understand SHA-256 hashes, file integrity checks, local hashing, and what a checksum can and cannot prove.
GuideHow to verify a file with SHA-256
Learn how to compare a file against an official SHA-256 checksum locally and understand what a matching hash does and does not prove.
GuideWhat does “no upload” mean for browser file tools?
Understand what no-upload file processing means, what it can protect, and what limitations still apply in a browser-based workflow.
Accuracy wording
This page avoids claims like “forensic-grade,” “military-grade,” “100% anonymous,” or “removes all hidden data.” Results are intended to be correct for supported file types and documented operations.
Last updated: June 14, 2026