Free File Hash Calculator
Calculate SHA-1, SHA-256, SHA-384, SHA-512, and MD5 hashes for any file. Verify file integrity and detect changes instantly.
What Are File Hashes?
A file hash is a fixed-length fingerprint of a file's contents. Even a tiny change to the file produces a completely different hash. Hashes are used to verify file integrity, detect corruption, and confirm file authenticity. Common algorithms include SHA-256 (modern, secure), MD5 (legacy), and SHA-1.
When to Use Hashes
- Verify downloads · Compare your file hash against the official checksum to ensure the file wasn't corrupted or tampered with.
- Detect file changes · Check if a file has been modified by comparing hashes over time.
- Find duplicate files · Identical files produce identical hashes, even if named differently.
- Security verification · Verify software and document authenticity using official published hashes.
Frequently Asked Questions
Which hash algorithm should I use?
SHA-256 is recommended for new applications. MD5 and SHA-1 are considered weak for cryptographic purposes but still work for basic integrity checks. This tool provides all options so you can match whatever standard your software uses.
Can you reverse a hash to get the original file?
No. Hashes are one-way functions. You can't reverse a hash to recover the original data. This is by design · it's what makes hashes secure for storing passwords and verifying file integrity.
Is MD5 safe for file verification?
MD5 is not cryptographically secure and should not be used for security applications. However, it still works for basic file corruption detection and general checksums. Use SHA-256 for any security-critical verification.