Privacy and data · Local browser tool
File Signature Checker
Compare a local file extension and reported MIME type with common leading-byte signatures.
Use the tool
Enter only data you are authorised to inspect. The result is a focused technical check, not a certification or full vulnerability assessment.
What it checks
Clear scope. Reproducible output.
- PDF, image, archive and executable signatures
- Extension and MIME consistency signals
- No file upload or content execution
Questions
Does File Signature Checker upload my input?
No. The working tool runs in the current browser tab. Avoid browser extensions or shared devices when handling sensitive material.
Does a passing result prove my system is secure?
No. It proves only the checks described on this page against the input you supplied. Server behaviour, business logic and runtime vulnerabilities require separate authorised testing.
Why is the result different from a live scanner?
This tool analyses pasted or local data. A live scanner observes network responses, DNS, TLS and redirects, so its evidence and scope are different.