SHA-1 Hash Generator
Hashes
Compare with a given hash
Paste the checksum you were given: hex, Base64, or a whole line like “abc123… file.iso”.
Check against common passwords
A hash cannot be decrypted, but weak passwords can be guessed. This compares your hash with the hashes of the 10,000 most common passwords, in your browser.
SHA-1 Hash Generator Online
Calculate the SHA-1 hash of a text or a file, or check a file against a SHA-1 checksum. The calculation runs in your browser, nothing is uploaded. The page also shows MD5, SHA-256, SHA-384 and SHA-512 of the same data.
How to get a SHA-1 hash
- Type or paste the text: the 40-character SHA-1 appears immediately.
- For a file, open the File tab and drop it (up to 2 GB).
- To verify a checksum, paste it into the Compare box.
Example: the SHA-1 of hello is aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d.
What is SHA-1?
SHA-1 (Secure Hash Algorithm 1) was designed by the NSA and published by NIST in 1995. It produces a 160-bit hash, written as 40 hexadecimal characters (28 characters in Base64). It was the main hash of the internet for about two decades: certificates, signatures, version control and download checksums.
Is SHA-1 still safe?
Not for security. Theoretical weaknesses were found in 2005. In 2017 researchers from CWI Amsterdam and Google produced the first practical collision (the SHAttered attack), and in 2020 a chosen-prefix collision was shown that makes attacks on SHA-1 based signatures realistic. Browsers stopped trusting SHA-1 certificates in 2017, and NIST has announced that SHA-1 is to be phased out by 2030. Use SHA-256 for new work.
SHA-1 is still found in legacy checksums, in Git (object IDs; Git detects the known collision attacks, and a move to SHA-256 is in progress) and in HMAC-SHA1 of one-time password apps, where the weakness of collisions does not matter.
How to check the SHA-1 of a file
Use the File tab, or the command line:
| System | Command |
|---|---|
| Linux | md5sum file.iso, sha1sum file.iso, sha256sum file.iso |
| macOS | md5 file.iso, shasum -a 1 file.iso, shasum -a 256 file.iso |
| Windows PowerShell | Get-FileHash file.iso -Algorithm MD5 (or SHA1, SHA256, SHA384, SHA512) |
| Windows Command Prompt | certutil -hashfile file.iso SHA256 |
| Any system with OpenSSL | openssl dgst -sha256 file.iso |
Frequently asked questions
How long is a SHA-1 hash?
160 bits: 40 hexadecimal characters.
SHA-1 or SHA-256?
SHA-256 for anything new. SHA-1 only when a legacy system requires it.
Can SHA-1 be decrypted?
No. It can only be guessed: the check against common passwords box compares your hash with the SHA-1 of the 10,000 most common passwords, locally in your browser.
Is my text sent to a server?
No, it stays in your browser.
Similar tools
Free online hash generator: MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of a text or a file up to 2 GB, HMAC, checksum comparison and SRI values. Calculated in your browser, nothing is uploaded.
Free online MD5 hash generator and checker: MD5 of a text or a file up to 2 GB, compare with a given checksum, check against common passwords. Calculated in your browser, nothing is uploaded.
Free online SHA-256 hash generator: SHA-256 and HMAC-SHA256 of a text or a file up to 2 GB, compare with a given checksum. Calculated in your browser, nothing is uploaded.
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