FILE & IMAGE TOOLS / LOCAL TOOL
File Signature Checker
Compare a file extension with its detected byte signature.
HOW IT WORKS
Comparing filename extensions with file signatures
The checker reads a small prefix of the selected file and compares known magic bytes with common formats.
Limits to keep in mind
Many formats share signatures, and a file can be truncated, polyglot or intentionally crafted. A matching signature does not prove the file is safe.
A PRACTICAL WORKFLOW
Use the result carefully.
01Choose a local file. The first bytes are inspected and compared with the filename extension when recognized.
02Run the utility and inspect the complete output.
03Keep files from untrusted sources isolated and use reputable malware scanning before opening them.
COMMON QUESTION
Does the checker upload or execute the file?
No. It reads a small byte prefix locally and does not execute the file.