File Type & Info Checker

A file called photo.jpg might actually be a PNG, a PDF or something you should not open. This tool reads the file’s signature bytes and compares them with its extension and the type your system reports, then shows the details and the first bytes in hex. Only the start of the file is read.

Choose a file or drop it hereAny file. Only the first 4 KB are read.

Runs entirely in your browser. Your input and files are not uploaded to any server.

How to use

Choose or drop a file.
Compare the detected format with the extension.
Use the hex preview to look closer if something seems wrong.

Examples

Renamed image

A “.jpg” whose bytes start with 89 50 4E 47 is really a PNG.

Suspicious attachment

A “.pdf” that starts with 4D 5A is a Windows executable — do not open it.

Privacy

Runs entirely in your browser. Your input and files are not uploaded to any server. See the privacy policy for what is stored in your browser (favorites and history only). Privacy policy

Check it yourself: open your browser’s developer tools, select the Network tab and use the tool. Your file never appears in an upload request. Once this page is saved for offline use, you can also disconnect from the internet and keep working. Ads and anonymous visit statistics, when enabled, make their own requests, but they never receive your files or text.

Frequently asked questions

Which formats are recognised?

Common images, PDF, ZIP-based formats (DOCX, XLSX, PPTX, EPUB, APK, JAR), archives, audio, video, fonts, executables, SQLite and more — about 40 signatures.

Can it prove a file is safe?

No. It identifies the format, not whether the content is malicious. Use antivirus software for that.

Is my file uploaded?

No. Only the first 4 KB are read, in your browser.

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