SHA-1 Hash Generator

Runs in your browser — your data is never uploaded.

Compute the SHA-1 hash of any text and get the 40-character lowercase hex digest. SHA-1 is retired for security use — browsers stopped trusting SHA-1 certificates in 2017 — but it remains the object identifier inside Git, the fingerprint format for SSH and PGP keys, and the checksum a long tail of older systems still expects. Uses your browser’s own audited WebCrypto implementation, on your device.

0 characters · runs entirely in your browser

How to use SHA-1 Hash Generator

  1. 1

    Paste or type the text you want to hash.

  2. 2

    Switch algorithm if you need MD5 or a SHA-2 digest instead.

  3. 3

    Click “Generate hash” and copy the 40-character hex digest.

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Frequently asked questions

Is SHA-1 still secure?+

No. The SHAttered attack demonstrated a real collision between two different PDFs in 2017, and the cost of producing one has fallen sharply since. Do not use SHA-1 for signatures, certificates or anything where an attacker benefits from two inputs matching.

Then why does Git still use it?+

Git uses SHA-1 to name objects, not to defend against attackers, and it has since added collision detection that rejects the known attack pattern. Migration to SHA-256 exists but is slow because every object ID in every repository and every tool would change.

How is this different from a Git commit hash?+

A commit hash is SHA-1 of a structured object — a header plus tree, parents, author, message — not of the message text alone. Hashing a commit message here will not reproduce its commit ID.

What should I use instead?+

SHA-256 for general use. Use SHA-1 only when a system you do not control requires it — verifying an old checksum, matching a key fingerprint, or interoperating with legacy software.

Is my input sent anywhere?+

No. Hashing uses crypto.subtle, the browser’s native implementation, entirely on your device — nothing is transmitted.

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