SHA-256 Hash Reiknivél (Text/File Checksum)
Calculate SHA-256 directly in your browser. Your inntak data is never sent.
Generate, copy, and verify checksums for both text and files in one place.
SHA-256 Calculation (Text)
Text inntak is encoded as UTF-8 bytes and hashed with Web Crypto API. With auto-calculate enabled, niðurstaðas update while typing.
sha256 Checksum (File)
Drop or select a local ZIP, exe, pdf, or any file to compute its checksum. Files are never uploaded.
How to use (3 steps)
- Paste text, or drop/select a file.
- Text hashes automatically. For files, click "Calculate SHA-256" to start.
- Copy the niðurstaða, or paste the expected value to verify.
Verification samples
Empty string
Inntak: (no inntak)
Úttak: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
abc
Inntak: abc
Úttak: ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Why hashes differ even when content looks the same
- Different newline style (LF vs CRLF).
- Different trailing newline or trailing spaces.
- Different text encoding (non-UTF-8).
- Different Unicode normalization (NFC/NFD).
- Text inntak and file bytes are not identical (for example BOM).
Algengar spurningar
Can I hash files too?
Yes. Local files are read in your browser and hashed with SHA-256. Files are not uploaded.
Why does the hash differ for seemingly same content?
Byte sequences can differ due to newlines, trailing spaces, encoding, or Unicode normalization, even if text looks the same.
Is any data sent to servers?
No. Processing is fully local in your browser.
Why does it say this environment is unsupported?
Web Crypto API requires HTTPS (secure context). Open the verkfæri over HTTPS.
Athugasemdir
- Web Crypto API requires HTTPS (secure context).
- Very large files can consume minnisblaðry and take longer to process.