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MIME Type Detector

Automatically detect and identify MIME types for any file based on extension and content

Free to use, no watermarks, runs in your browser—nothing uploads to our servers

Select Files to Detect MIME Types

Keep file preview metadata in this browser only When enabled, file names, sizes, MIME types, and analysis summaries are stored locally on this device only. This helps restore preview outputs across tabs using the same storage profile. Your files never upload.

File and MIME type cards showing categorized file formats

Choose files to identify

Add files to infer their MIME types, compare browser-reported types, and spot unknown formats before you share or process them.

Works well for mixed batches
Useful when file extensions look wrong

Common MIME Types Reference

.pdf

application/pdf

PDF Document

.jpg

image/jpeg

JPEG Image

.png

image/png

PNG Image

.gif

image/gif

GIF Image

.svg

image/svg+xml

SVG Vector

.mp4

video/mp4

MP4 Video

.mp3

audio/mpeg

MP3 Audio

.zip

application/zip

ZIP Archive

.json

application/json

JSON Data

.xml

application/xml

XML Document

.txt

text/plain

Plain Text

.html

text/html

HTML Document

.css

text/css

CSS Stylesheet

.js

application/javascript

JavaScript

Understanding MIME Types

Structure: MIME types follow the format "type/subtype" (e.g., "image/jpeg")

Main Categories: image, video, audio, text, application, multipart, and more

Usage: Web servers, email clients, and browsers use MIME types to handle files correctly

Default Type: "application/octet-stream" is used for unknown binary files

Jump to helper sections

What is a MIME type?

MIME (Multipurpose Internet Mail Extensions) types are standard identifiers for file formats on the internet. They help browsers and servers handle files correctly (e.g., "image/jpeg", "application/pdf").

How does MIME type detection work?

This tool detects MIME types using the file extension and the browser's built-in type information. It cross-references common file extensions to provide accurate MIME type identification.

Why is my file showing "application/octet-stream"?

This is the default MIME type for unknown or binary files. It means the file extension is not recognized or the browser cannot determine the specific type.

Can I change a file's MIME type?

You cannot change the actual file format, but you can rename the file extension to match the correct format. The MIME type is determined by the file's content and extension.

Report a bug

If this tool misbehaves, share a quick summary so we can investigate. We include the tool URL automatically—no need to copy and paste.

Session file-tool analysis history

Keep a local, session-only record of successful file analyses in this browser session.

No analysis results yet. Run a file analysis to populate this panel.

Session download history

Re-download generated file outputs from this browser session.

No generated outputs yet. Use a file tool in this session to populate this panel.