ハッシュ計算

Any change to the file — even invisible metadata or line-ending differences — changes every character of the hash. Compare hashes byte-for-byte to confirm files are truly identical.

MD5 is fine for basic integrity checks (like confirming a download wasn't corrupted) but should never be used for security purposes like password storage — use SHA-256 or higher for anything security-sensitive.

No. Hashing happens entirely in your browser using the file directly from your device — nothing is uploaded.