SHA-1 Hash Generator
Generate a SHA-1 hash from text, hex or Base64, with hex or Base64 output and a per-line mode. SHA-1 is broken for security — use SHA-256 instead. Runs in your browser.
SHA-1 produces a 160-bit (40-hex-character) hash. It was once the workhorse of digital signatures and version control, but a practical collision was demonstrated in 2017 (the "SHAttered" attack), so it must not be used for security. This generator is for legacy checksums and comparisons; it runs in your browser.
How to use this tool
- Paste text, hex or Base64.
- Choose whether to hash each line separately.
- Pick hex or Base64 output.
- Copy the result.
Formula
SHA-1 processes 512-bit blocks through 80 rounds of bitwise operations and additions to produce a 160-bit digest.
Example
SHA-1 of "abc" is a9993e364706816aba3e25717850c26c9cd0d89d, from the FIPS 180 test vector.
Frequently asked questions
Is SHA-1 safe to use?
No, not for security. Researchers produced two different files with the same SHA-1 hash in 2017, so it can no longer protect signatures or certificates. Use SHA-256 instead.
Why is it still around?
Older systems, Git object IDs and some legacy checksums still use SHA-1. Generating it is useful for comparing against those existing values.
Does hashing the same text always give the same result?
Yes. A hash is deterministic, so identical input always yields the identical digest.
How long is a SHA-1 hash?
Always 160 bits: 40 hexadecimal characters, or 28 Base64 characters ending in one "=". Git shows commit IDs in the same 40-character form, although newer Git versions can also use SHA-256 for a repository.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/sha-1-hash-tool/
Cite or embed this tool
kakaoCalc. (2026, November 8). SHA-1 Hash Generator. https://kakao.mobile/tools/sha-1-hash-tool/
“SHA-1 Hash Generator.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/sha-1-hash-tool/.
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