SHA-1 Hash Generator
Generate SHA-1 hash values from any text input online. Free, fast, and runs entirely in your browser.
Input
Output
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, rendered as a 40-character hexadecimal string. It was designed by the NSA and published by NIST in 1995 as part of the Secure Hash Standard.
While SHA-1 has been deprecated for most security applications due to demonstrated collision attacks, it is still used in legacy systems and for non-security-critical purposes like version control (Git). The algorithm is defined in RFC 3174. This tool computes the SHA-1 hash of your entire input text using the Web Crypto API.
How to Use This Tool
Enter Your Text
Type or paste text into the left editor. You can also click Sample to load example text, or Upload a text file.
View the SHA-1 Hash
The right panel displays the SHA-1 hash of your input automatically. The hash updates in real time as you type.
Copy or Download
Click Copy to copy the hash to your clipboard, or Download to save it as a text file.
Hash Examples
Here is an example of SHA-1 hashing:
Input Text
SHA-1 Hash Output
Frequently Asked Questions
Is SHA-1 still secure?
No. In 2017, researchers demonstrated the first practical SHA-1 collision in the SHAttered attack. SHA-1 should not be used for digital signatures or certificates. Use SHA-256 or SHA-512 for security-critical applications.
Why was SHA-1 deprecated?
SHA-1 was deprecated because collision attacks became feasible. Google and CWI Amsterdam demonstrated a real-world collision, detailed in this Google Security blog post. Major browsers and certificate authorities have since stopped trusting SHA-1 certificates.
Is my data sent to a server?
No. All hashing is performed locally in your browser using the Web Crypto API. No data ever leaves your machine.
Does Git still use SHA-1?
Yes. Git historically uses SHA-1 for commit and object hashing. However, Git is transitioning to SHA-256 for improved security. The collision resistance is less critical for Git because an attacker would also need write access to the repository.
Related Tools
References: FIPS 180-4 Secure Hash Standard and MDN SubtleCrypto.digest().