Office Password

• Choose one DOCX, XLSX or PPTX file.
• Choose Encrypt and confirm a new password, or choose Decrypt and supply its known password.
• Process locally, read the integrity status, and download the resulting document. Keep encryption passwords safely; this tool cannot recover them.

Encrypt a DOCX with a new password, then decrypt it with the same password to recover its original ZIP bytes.

• One file: plaintext 20 MiB, encrypted 24 MiB; ZIP 1,000 entries, 16 MiB per entry, 64 MiB expanded total; CFB 128 directory entries, 17 path components, 2 MiB metadata; native 256 MiB memory and a 120-second job deadline.
• Agile AES-CBC with SHA-1/256/384/512 and 128/192/256-bit keys can be decrypted within the supported Office password profile, up to 1,000,000 KDF iterations. Encryption writes AES-256/SHA-512 with 100,000 iterations and fresh browser-generated cryptographic keys/salts.
• Agile HMAC must verify before any plaintext result. Standard AES/SHA-1 decryption has no cryptographic package integrity tag: ZIP checksums detect damage but do not authenticate content. RC4, binary DOC/XLS/PPT, certificate encryption, macros and password recovery are unsupported.
• Passwords use exact Unicode and spaces, at most 255 UTF-16 units, without NUL. Encryption requires a nonempty password; decryption can use an empty supplied password. Reset clears the input fields; JavaScript cannot guarantee physical memory erasure.
• Decrypted downloads are unencrypted. Document content, metadata, embedded files and editing restrictions are preserved; successful decryption is not a safety, signature-trust or authorship check. Browser memory limits can be lower on mobile. Decoder assets download first; files and passwords are not uploaded.