Developer Tools / BROWSER-ONLY UTILITY
SHA Checksum Calculator
Compare the bytes you have with a digest obtained from a trusted source. The calculation happens locally; a matching value still needs that source to mean anything.
Text is encoded as UTF-8 without trimming. Binary files are limited to 10 MiB and are not decoded as text. Limit: 100,000 characters.
Typing in the text box clears the selected file. Text is hashed as UTF-8 exactly as entered, including spaces and line endings.
Loading local tool code...
Input stays in this tab. No upload, AI call, analytics or ads. Reset clears the workspace. Clipboard copies and downloaded files remain under your control.
Result
Technical details (optional)
Review the result before sharing. It may still contain personal or confidential information.
Text and file bytes are different inputs
Text mode hashes the UTF-8 encoding of the text exactly as entered. It does not trim a final newline, change CRLF to LF or normalise Unicode. Those differences can change the digest. File mode hashes the selected file as raw bytes, including zero bytes and invalid UTF-8. An empty file has a valid digest, while an empty text workspace asks for input.
Algorithms and comparison
SHA-256 is the default. SHA-384 and SHA-512 are also supported through the browser Web Crypto digest API in a secure context. Expected values must contain exactly 64, 96 or 128 hexadecimal characters respectively. Case is ignored for the comparison, but spaces, filenames and checksum-file syntax are rejected. No MD5 mode or password-hashing function is provided.
What a match tells you
A match says that the calculated digest equals the value you supplied. If both the file and expected digest came from the same compromised location, that comparison cannot establish a trusted publisher. This tool does not inspect file contents for malware, validate a digital signature, identify a downloaded product or certify safety.
Keep the workload local and bounded
The browser processes the complete buffer rather than a streaming file. Raw files are therefore limited to 10 MiB; text remains limited to 100,000 characters. The output contains the digest and byte count, not the original file. Clipboard history and any downloaded result are outside the tab. No file is uploaded to calculate or compare a checksum.
References
Documentation reviewed: . Rule results describe the supplied text, not a live application test.
Useful next steps
Maintained by MetaCyberGuru. A review point may need source, runtime or deployment context before you act on it.