Checksum Generator — SHA-256, SHA-1, Local
Calculate a hexadecimal SHA-256 or SHA-1 digest of a message to compare exact text across environments. A digest is a derived value rather than reversible encryption.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
Numbers stay on your device. Nothing is sent to a server.
How to use this tool
Preserve the original whitespace and line endings and select an algorithm. This implementation uses the browser Web Crypto API, which requires a suitable secure context.
Results and examples
The SHA-256 digest of abc begins ba7816bf. Compare the complete 64-character hexadecimal output, not just the abbreviated display; appending a newline produces another digest.
Limitations
- SHA-1 should not be selected for new cryptographic signature designs.
- An unkeyed digest alone does not authenticate the sender.
Fields
| Field | Guidance and constraints |
|---|---|
| Message | Check the unit and format displayed beside this field. |
| Algorithm | SHA-256 / SHA-1 |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
How much of the digest should be compared?
The SHA-256 digest of abc begins ba7816bf. Compare the complete 64-character hexadecimal output, not just the abbreviated display; appending a newline produces another digest.
Does a matching digest authenticate its sender?
SHA-1 should not be selected for new cryptographic signature designs. An unkeyed digest alone does not authenticate the sender.
Related tools
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