About the File Type Checker
File extensions can lie. FileStripe reads the first bytes of the file, the 'magic number' that identifies its true format, and tells you what it really is, the correct extension and MIME type.
It warns you if the extension does not match the content, which is a common trick used to disguise malware as documents or images.
How to use the File Type Checker
- Choose a file.
- See the detected type, extension and MIME type.
- Check the warning if the extension is wrong.
Features
- 80+ signaturesImages, documents, archives, media, executables.
- Mismatch warningSpot disguised files.
- Hex previewSee the first bytes.
- PrivateRead locally.
Frequently asked questions
How do I open a file with no extension?
Find its real type here, then rename it with the suggested extension.
Is the File Type Checker free?
Yes. The File Type Checker is completely free with no sign-up, no watermarks, no daily limits and no premium tier.
Are my files uploaded to a server?
No. FileStripe processes your files locally in your web browser using JavaScript. Nothing is uploaded, so the File Type Checker is safe for private photos and confidential documents and even works offline once the page has loaded.
Does it work on iPhone and Android?
Yes. The File Type Checker works in Safari, Chrome, Firefox, Edge and Samsung Internet on phones, tablets and computers. On a phone you can pick files from your photo library or files app and share the result straight to another app.
Last updated · Processing happens locally in your browser.