File Type Detector
Find out what a file really is from its contents, not its name. Spot misnamed downloads, files without an extension and disguised programs.
Free · No upload · 100% on your device
Choose files, or drop them here.
Any file type · Nothing is uploaded.
How to use File Type Detector
- Choose files, or drop it on the page.
- Check the details.
- Select “Detect”.
- Download the result. Your original file is left unchanged.
Private by design. Everything you type, open or record is processed in this browser tab and is never uploaded to KittySuite.
About File Type Detector
Around 70 formats are recognised by their signatures, including Office documents inside ZIP containers, HEIC photos and MP4 variants. A “.pdf” that is really a Windows program is a common malware trick, so mismatches are highlighted.
Your files are read in this browser tab and never uploaded. Nothing is stored after you close the page, and there is no size limit beyond your device’s memory.
File Type Detector: frequently asked questions
How do I find out what kind of file I have?
Choose the file. Its type is identified from its contents, which works even when the extension is missing or wrong.
How many formats are recognised?
Around 70, including Office documents inside ZIP containers, HEIC photos and MP4 variants.
Can it warn me about disguised programs?
Yes. A mismatch, such as a “.pdf” that is really a Windows program, is highlighted. It is a check, not an antivirus scan.
What should I do with a file without an extension?
Detect its type here, then rename it with the matching extension so your apps can open it.