SHA-1 Hash Generator Online

Generate SHA-1 hash values from text and files — legacy compatibility and Git integration

What Is SHA-1 Hashing?

SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function that produces a 160-bit (20-byte) hash value, represented as a 40-character hexadecimal string. Designed by the NSA and published by NIST in 1995, SHA-1 was widely used for digital signatures, certificate validation, and data integrity checks for over two decades.

While SHA-1 has been deprecated for security-critical applications since a practical collision attack was demonstrated by Google in 2017 (the SHAttered attack), it remains in active use for non-security purposes. Git uses SHA-1 for commit IDs and object addressing, many legacy systems still rely on SHA-1 checksums, and some older APIs require SHA-1 signatures. For new security applications, SHA-256 or SHA-3 should be used instead, but SHA-1 remains necessary for interoperability with existing systems.

How to Generate a SHA-1 Hash Online

1. Enter your text into the input field or upload a file
2. The SHA-1 hash generates automatically, producing a 40-character hex string
3. Copy the hash for Git compatibility, legacy system integration, or integrity checks
4. Compare two SHA-1 hashes to verify whether files or strings are identical
5. For security-sensitive applications, consider using the SHA-256 generator instead

Why Use PinusX for SHA-1 Generation?

PinusX computes SHA-1 hashes with 100% client-side processing in your browser. Your input data never leaves your device. While SHA-1 is often used for non-sensitive purposes like Git commit verification, developers still hash content that should remain private — source code, proprietary files, and internal data. In November 2025, jsonformatter.org leaked over 80,000 user credentials processed through their servers. PinusX eliminates this risk by running SHA-1 computation entirely in your browser tab using the Web Crypto API, with no network transmission of your data.

Frequently Asked Questions

Is SHA-1 still safe to use?

SHA-1 is not safe for security-critical applications. A practical collision attack was demonstrated in 2017 (SHAttered). Do not use SHA-1 for digital signatures, certificate verification, or password hashing. It is still acceptable for non-security uses like checksums, content addressing (Git), and deduplication where collision resistance against targeted attacks is not required.

Why does Git use SHA-1?

Git adopted SHA-1 when it was designed in 2005, when SHA-1 was still considered secure. Git uses SHA-1 to generate unique identifiers for commits, blobs, trees, and tags. Git is transitioning to SHA-256 (available as an experimental option), but SHA-1 remains the default. For Git's use case, the known collision attacks do not pose a practical threat.

How does SHA-1 compare to SHA-256?

SHA-1 produces a 160-bit hash (40 hex chars) while SHA-256 produces a 256-bit hash (64 hex chars). SHA-256 is stronger with no known attacks. SHA-1 is slightly faster but the difference is negligible for most applications. For new projects, always choose SHA-256 unless you need SHA-1 for legacy compatibility.

Can I verify Git commit hashes with this tool?

This tool computes a plain SHA-1 hash of the input text. Git commit hashes include metadata (tree, parent, author, committer, message) in a specific format prefixed with 'commit <size>\0'. So the hash of a commit message alone will not match the Git commit hash. Use this tool for general SHA-1 computation.

Your data never leaves your browser. 100% client-side processing.