File Hash Checker
Calculate and verify MD5, SHA-1, SHA-256, SHA-512 file hashes locally
What is a file hash?
A file hash is a unique fixed-length string generated from file contents using a cryptographic algorithm. Even a tiny change in the file produces a completely different hash, making it ideal for verifying file integrity.
How do I verify a file download?
Copy the expected hash from the download page, select the same algorithm, paste it into the verify field, and click Compare. A match confirms your download is intact and hasn't been corrupted.
Is my file uploaded to a server?
No, all hash computation happens locally in your browser using JavaScript. Your files never leave your device, ensuring complete privacy and security.
Which hash algorithm should I use?
SHA-256 is recommended for most purposes as it balances security and speed. MD5 is fast but not collision-resistant. SHA-512 provides the highest security for sensitive applications.
What's the difference between MD5 and SHA-256?
MD5 produces a 128-bit hash and is faster but vulnerable to collision attacks. SHA-256 produces a 256-bit hash, is more secure, and is recommended for integrity verification in modern applications.
Can I check multiple files at once?
Yes, you can select multiple files and the tool will calculate hashes for each file individually, displaying results in a clear list format.
How long does hash calculation take?
For small files, it's nearly instant. For large files (GB+), it depends on file size and your device speed. The progress bar shows real-time status.
What are checksums used for?
Checksums verify data integrity after downloads, transfers, or storage. They detect corruption, tampering, or incomplete transfers by comparing calculated hashes with expected values.
Why do different algorithms produce different length hashes?
Each algorithm uses different mathematical operations. MD5 produces 128 bits (32 hex chars), SHA-1 produces 160 bits (40 hex chars), SHA-256 produces 256 bits (64 hex chars), and SHA-512 produces 512 bits (128 hex chars).
Can hash collisions occur?
Theoretically yes, but practically no for SHA-256 and SHA-512. MD5 and SHA-1 have known collision vulnerabilities, which is why SHA-256 is recommended for security-critical applications.
How does hash verification protect against tampering?
If someone modifies a file, its hash changes completely. By comparing the original hash with the calculated hash, you can detect any unauthorized modifications.
What file sizes are supported?
The tool supports files of any size, from a few bytes to several gigabytes. Large files are processed in chunks to maintain performance and low memory usage.