Detect File Type
Detect a file's true type from its contents
Got a file with no extension, or one that won't open? Upload it and we'll read what's inside to tell you the real file type, the right extension and its MIME type.
Detected file type PNG image data, 262 x 296, 8-bit/color RGBA, non-interlaced
vacation.doc, but it begins with the same bytes every PNG image begins with, so it's really a PNG picture.How it works
-
Choose a file
Drag it onto the box above or press the box to browse. Files with no extension, or the wrong one, are fine.
-
We read its contents
The tool analyzes the bits and bytes inside the file. The file name is never used to decide the type.
-
See the real type
The results open in a new tab with the file type, suggested extensions and MIME type.
Why a file extension can be wrong
A file extension is just the last part of a file's name, so it can be missing, mistyped or changed by anyone. Rename a .gif image to .doc and your computer will try to open it with a word processor, even though nothing inside the file has changed.
That means a file called report.doc isn't necessarily a Word document. It could be any type of file with an incorrect extension. Detect File Type ignores the name and looks at the file's actual contents to tell you what it really is.
What the results include
- File type
- A description of the file's real format, such as "PNG image data".
- Suggested extensions
- The extension the file should have, so you can rename it and open it with the right app.
- MIME type
- The standard label, like
image/png, that browsers, web servers and programs use to handle a file. Handy if you're writing code. - Extra details
- For some formats, such as JPEG and PNG images, you'll also see details like pixel size, color depth and whether the image is interlaced.
Common questions
Is Detect File Type free?
Yes. The file type detector is 100% free to use.
Does it look at the file name or extension?
No. The type is worked out from the file's contents only, which is why it can spot files that have been renamed or saved with the wrong extension.
My file has no extension. Can you still identify it?
Yes, that's exactly what this tool is for. Once you know the type, add the suggested extension to the file name (for example, change photo to photo.png) so your computer knows which app to open it with.
What is a MIME type?
A MIME type is a standard label for a file's format, written as a type and subtype, such as image/png or application/pdf. Browsers, email programs and web servers use it to decide how to handle a file.