How to magic byte validator — frequently asked questions
- Step 1Drop your file — Drag any file onto the validator. No account or installation needed.
- Step 2Read the result card — The card shows declared extension, detected MIME, match status, and a short explanation of any mismatch.
- Step 3Take action — Match → safe to process. Mismatch → treat with caution; read the FAQ answer for that specific conflict type.
Frequently asked questions
Does the tool upload my file?+
Never. Detection runs entirely in your browser using the file-type library. Zero bytes are sent to any server. You can verify this in Chrome DevTools → Network tab — no requests appear during processing.
What does 'Unknown type' mean?+
The file's first bytes don't match any signature in the database. This can mean the file is corrupted, encrypted (random-looking bytes), or a proprietary format not covered by the 300+ format library.
My PDF shows as a ZIP — is it broken?+
No. Modern .docx, .xlsx, and .pptx files are ZIP archives. Some PDF generators also embed ZIP-like containers. If the extension is .pdf and detection says application/zip, open it in Notepad — if it starts with 'PK', it is likely an OOXML file misnamed as .pdf.
Can I validate multiple files at once?+
Yes. Drop multiple files and each receives its own result card. Pro tier removes the 5-file free limit.
Privacy first
Every JAD Security operation runs entirely in your browser. Files, passwords, and PGP private keys never leave your device — verified by zero outbound network requests during processing.