String to SHA-1
Generate the SHA-1 hash of any text. Free online tool — plus why SHA-1 is fine as a checksum but deprecated for security.
Paste text and get its SHA-1 digest — a 40-character hex fingerprint. SHA-1 is fast and still appears in legacy systems, but it is deprecated for security after practical collisions.
Where SHA-1 is acceptable
As a non-security checksum — deduplication, quick integrity checks, matching against a legacy SHA-1 value — SHA-1 is fine and widely supported. Git famously uses it for object IDs. HMAC-SHA1 also remains safe, which is why TOTP still uses it.
Do not use it for signing
For signatures, certificates, or anything an attacker could target, SHA-1 is broken — collisions are practical. Use SHA-256 there. Our tool also outputs SHA-256 and SHA-512 for exactly that reason.
Try it now — free, no signup
Use the hash generator in your browser. Then, when you need it at scale with an API key and higher limits, grab the full Eveses API.