Inspects an uploaded file or pasted text: size, type sniffed from the file signature, Shannon entropy (high values suggest compression or encryption), first bytes, text encoding and line/word/character counts with line-ending style, and CRC32, MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests. Paste an expected checksum to verify it against every digest. The secondary pane holds sha256sum-style lines. Everything runs locally.