ESC

SHA-1 Generator

SHA-1 is deprecated for cryptographic security. It is still used for file checksums and Git commit hashes, but not recommended for security-critical applications. Consider using SHA-256 or SHA-512 for security purposes.
Enter any text to compute its SHA-1 hash value

Drag & drop a file here

or click to browse
()

Hash Information

0
Input Size
0
Hash Length
SHA-1
Algorithm
160
Bits
40
Hex Characters
All processing happens in your browser. No data is sent to any server.

Usage Examples

Git Commit Hash

Git uses SHA-1 hashes to identify commits. Generate SHA-1 hashes to understand how Git versioning works internally.

File Checksum

Compute the SHA-1 checksum of a file for basic integrity verification when downloading or sharing files.

Legacy System Compatibility

Generate SHA-1 hashes for compatibility with older systems that still require SHA-1 checksums or fingerprints.

Features

SHA-1 Legacy Support

SHA-1 produces a 160-bit hash, still widely used for file checksums, Git commit identification, and legacy system compatibility

File Hashing Support

Hash any file type with drag & drop or file browser support for checksum verification

Hash Comparison

Compare generated hashes with expected values to verify file integrity instantly

Client-Side Processing

All hashing is done locally in your browser using Web Crypto API, ensuring complete privacy

How to Use?

1

Enter Text or Select File

Type or paste text into the input field, or drag & drop a file to hash.

2

Generate Hash

Click the Generate Hash button or enable real-time hashing for automatic computation.

3

Copy or Compare

Copy the generated SHA-1 hash to clipboard or compare it with an expected hash value.

Frequently Asked Questions

SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function that produces a 160-bit (40-character hex) digest from any input. It is a one-way function: given the same input, you always get the same hash, but there is no way to recover the original input from the hash. Example: SHA-1 of "hello" = aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d.

Not for security purposes. In 2017, Google's SHAttered project demonstrated the first practical SHA-1 collision attack. SHA-1 is officially deprecated for TLS certificates, code signing, and digital signatures. For those use cases, use SHA-256 or SHA-512. However, SHA-1 remains acceptable for non-security uses: Git commit IDs, file deduplication, cache keys, and checksums where collision resistance is not critical.

Historical reasons and backward compatibility. Git has used SHA-1 since its creation in 2005. Git is transitioning to SHA-256 (available since Git 2.29), but SHA-1 remains the default. For Git's use case — identifying commits and blobs — the known collision attacks are not a practical threat, because exploiting them in a Git repository would require cooperation from the repository owner.

SHA-1 produces a 160-bit (40 hex char) digest. SHA-256 produces a 256-bit (64 hex char) digest. SHA-512 produces a 512-bit (128 hex char) digest. SHA-256 and SHA-512 belong to the SHA-2 family, which has not been broken. SHA-1 has known collision vulnerabilities. For security applications, use SHA-256 or SHA-512. SHA-512 is faster than SHA-256 on 64-bit hardware.

Not directly — SHA-1 is a one-way function with no known mathematical reversal. However, short or common inputs are vulnerable to rainbow table lookup: attackers precompute hashes for millions of common strings and match them. This is why SHA-1 (or any hash alone) should never be used to store passwords. For passwords, use bcrypt, Argon2, or scrypt.

Generate a SHA-1 hash, then paste an expected hash into the Compare Hash field. The tool compares both strings character by character and immediately shows whether they match. Useful for verifying file downloads against published checksums, or confirming that two strings produce the same hash.

Yes. Drag and drop any file onto the file drop area, or click to browse. The tool reads the file locally using the FileReader API and computes the SHA-1 hash without uploading anything. Works for any file type: executables, archives, documents, images.

No. All hashing runs locally in your browser via the Web Crypto API. No text, no files, no hashes are sent to any server. Works offline — disconnect from the internet and the tool behaves identically.

What Is SHA-1?

SHA-1 is a cryptographic hash function that produces a 160-bit (40-character hex) digest. It was the industry standard for years - SSL certificates, code signing, you name it. In 2017, Google demonstrated a practical collision attack (SHAttered), and SHA-1 was officially deprecated for security use. But here's the thing: it's still everywhere in non-security contexts, and for those uses, it works just fine.

Where SHA-1 Is Still Relevant

Git is the most visible example - every commit hash you see is SHA-1. File integrity checks for non-sensitive downloads, data deduplication, content-addressable storage, and cache key generation all commonly use SHA-1. It's faster than SHA-256 and produces shorter hashes, which matters when you're generating millions of them for something like a dedup system.

SHA-1 vs SHA-256: When Does It Matter?

If someone could gain something by crafting a collision (forging a certificate, tampering with a signed document), use SHA-256 or better. If you're just checking whether a file downloaded correctly or generating a quick fingerprint for caching, SHA-1 is fine. The collision attack requires significant computational resources and produces two documents with the same hash - it doesn't let you match an arbitrary existing hash.

How This Tool Works

Type text or drop a file, and the browser's Web Crypto API computes the SHA-1 hash locally. There's a real-time mode that hashes as you type, and a comparison field where you can paste an expected hash to verify a match. The deprecation warning at the top reminds you not to use SHA-1 for security - but for everything else, go ahead.

Privacy

All processing happens in your browser. No uploads, no server calls, no logging. Disconnect from the internet and the tool works identically.

Security and Privacy

Your data security is our priority

Local Processing

All processing happens in your browser

No Data Transfer

Your data is not sent to our servers

No Data Storage

No data is stored or shared

SSL Encryption

SSL encryption for secure connection

Next Step

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