About File Info
A file's extension can be missing or wrong, and the details you need are often hidden. This tool reads the start of any file to identify its real type from its signature, covering images, PDFs, audio, video, archives, Office files, programs and more. It also shows the exact size, the last modified date and type-specific details: dimensions and megapixels for images, page count and title for PDFs, duration for audio and video, and lines, words and line endings for text. It warns when the extension doesn't match the content.
How to Use It
- 01
Add files
Drop one or more files into the box, or tap to choose them.
- 02
Inspect
Press Inspect to read each file.
- 03
Read the details
Check the table, or download the details as JSON.
Questions
How does it know the real file type?
Most formats start with a fixed signature, such as %PDF for PDFs. The tool compares the first bytes with a list of known signatures, regardless of the file name.
Why does it say my file's extension is wrong?
The content matches a different format than the name suggests, for example a PNG named photo.jpg. Renaming it to the right extension often fixes apps that refuse to open it.
Can it identify every file?
It recognises about thirty common formats and plain text. Rare formats are reported as unknown binary data.
Is my file uploaded?
No. Files are read in your browser.