What is a file hash and why does it matter?+
A file hash is a fixed-length fingerprint generated from a file's contents. The same file always produces the same hash. Even a single changed byte produces a completely different hash. This lets you verify a downloaded file hasn't been corrupted or tampered with.
Which hash algorithm should I use?+
SHA-256 is the recommended standard for file integrity verification. MD5 and SHA-1 are faster but cryptographically broken - don't use them for security. SHA-512 provides extra margin but SHA-256 is sufficient for file verification.
How do I verify a file download using its hash?+
The software publisher provides a hash value. Download the file, drag it here, and compare the generated hash to the published value. An exact match means the file is authentic and uncorrupted.
Are my files uploaded to a server?+
No. All hashing happens locally in your browser using the Web Crypto API. Your file never leaves your device. This is safe for confidential documents and large files.