Hash checker

No. Hashing happens entirely in your browser via WebCrypto. The file is read into memory locally, hashed, and everything is gone as soon as you close the tab. No upload, no log, no analytics.

WebCrypto, the browser API we use for hashing, deliberately doesn't support MD5. MD5 has been known to be broken for cryptographic purposes since 2004 and is being actively phased out. For file integrity checks (the most common reason people want MD5), SHA-256 is a fine replacement. Source only publishes MD5? Ask for SHA-256, or rely on other signals (HTTPS download, GPG signature).

All are hash functions that turn an input into a fixed-length fingerprint. SHA-1 (40 hex chars) is deprecated for crypto purposes but fine for file integrity. SHA-256 (64 hex chars) is the modern standard. SHA-512 (128 hex chars) has more room against collision attacks but isn't practically stronger for file verification. Pick whatever the source publishes.

Not directly, but via a workaround: hash the first file, copy the SHA-256, hash the second file, paste the copied hash into 'Compare against'. Match = identical files, mismatch = something differs.