How to Use the File Magic Bytes & True MIME Type Signature Inspector
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1
Drop any file into the inspector.
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2
Read the first 16 raw hexadecimal header bytes.
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3
Verify if the magic signature matches the claimed file extension (e.g., %PDF-1.4, FF D8 FF for JPEG, PK for ZIP/DOCX).
Practical Example & Use Case
Common Real-World Scenario
Unmasking a dangerous Windows executable file (`.exe` starting with `4D 5A` / MZ) falsely renamed to `invoice.pdf`.
Technical Notes & Limitations
Browser Engine Architecture
Reads the first 32 bytes via browser FileReader API with zero server transmission.
Frequently Asked Questions
What are magic bytes?
Magic bytes are specific byte sequences at the very beginning of a file that uniquely identify its true format regardless of the file extension.