What is it?
What Type Is This File? tells you what kind of file you really have, whatever its name says. It reads the first bytes of the file to identify PDF, JPG, HEIC, MP4, ZIP, APK and many more, and warns when the file name ending is wrong.
Who is it for?
Anyone with a file that has no extension or won’t open, people checking suspicious email attachments, and IT support staff.
How to use it
- Choose any file or drag it in: only the first 64 KB is read, nothing is uploaded.
- Read the detected type and any warning.
- Rename the file with the correct extension if needed.
Examples
- A “photo” from an iPhone that won’t open on Windows is often HEIC: convert it to JPG.
- A file called “invoice.pdf.exe” is a program pretending to be a PDF: delete it.
Errors and how to fix them
- Unknown type: plain text and some rare formats have no magic number; try opening it in a text editor.
- Warning: name doesn’t match: e.g. “photo.jpg” that’s really an .exe or .apk: don’t open it.
Questions people ask
- Is my file uploaded? No, only the first 64 KB is read, on your device.
- Can it open the file? It identifies it; then use the right app or converter.
Practical tip
If a file from WhatsApp or email turns out to be a different type than its name, especially a program, delete it and ask the sender to confirm.
Open the tool: What Type Is This File?
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.