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ToolSuite
File & Archive Tools

File MIME Type Detector

Work out the correct Content-Type for a file by inspecting its contents.

or drag it here

Any file · up to 200 MB

Processed in your browser

Fill in the form and press “Detect type” to see the result here.

How to use it

  1. 1Select your file, or drag and drop it onto the upload area.
  2. 2Adjust the options if you need something other than the defaults.
  3. 3Press the button. Everything happens on your device.
  4. 4Download the result.

About the File MIME Type Detector

Serving the wrong Content-Type is a real bug: a stylesheet sent as text/plain is ignored by the browser, and a user upload served as text/html instead of a download can turn into stored cross-site scripting.

The type here is derived from the file contents, not from its name, which is the only trustworthy source.

Questions people ask

Is your file uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your file never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.

Is it free, and do I need an account?

Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.