What is the MIME type for a JSON file?

The MIME type for JSON is application/json. Search for json above to confirm it, and note that JSON-LD uses application/ld+json.

What MIME type should I use for a file with no known extension?

Use application/octet-stream. It is the standard generic type for binary data, and it prompts the browser to download the file instead of trying to render it.

Why does one extension show more than one MIME type?

Some formats have several registered or historically used types. For example, .js is officially text/javascript but application/javascript is still common, and .ico appears as both image/vnd.microsoft.icon and image/x-icon. The primary, recommended type is listed first with the alternate noted beside it.

Is a MIME type the same as a file extension?

No. A file extension is a naming convention on the filesystem, while a MIME type is the format label sent over the network in the Content-Type header. Servers map extensions to MIME types, but browsers rely on the MIME type, not the extension, to decide how to handle a response.

Are my lookups sent to a server?

No. The entire MIME type table is bundled with the page and searched in your browser, so nothing you type is uploaded.

MIME Type Lookup — Extension to Content-Type

This free MIME type lookup finds the correct MIME (media) type for any file extension, and works in reverse too: type part of a MIME type to see every extension that uses it. It covers more than 90 of the everyday web formats — documents, images, audio, video, fonts, archives, and 3D models — each labelled with its category so you can pick the right Content-Type header for a download, an upload validator, or a static file server.

MIME types tell browsers and servers how to interpret a file, so getting them right is the difference between a PDF opening inline and a page of garbled bytes. Everything here is a static reference that runs entirely in your browser — no lookups are sent anywhere.

How to use MIME Type Lookup

Type a file extension, with or without the leading dot (for example png or .docx), to see its MIME type.
Or type part of a MIME type (for example image/ or json) to list every matching extension.
Use the category buttons to narrow results to text, application, image, audio, video, font, or model types.
Click the copy icon on any row to copy the MIME type for use in a Content-Type header or a config file.

What a MIME type is

A MIME type (also called a media type or content type) is a two-part label of the form type/subtype, such as text/html or image/png. The first part is the general category and the second identifies the exact format. Web servers send it in the Content-Type response header so the browser knows whether to render, play, or download the response, and browsers send it when uploading files. An optional parameter such as charset=utf-8 can follow the subtype.

Content-Type: text/html; charset=utf-8
Content-Type: application/json
Content-Type: image/svg+xml

MIME types as they appear in an HTTP Content-Type header.

The main categories

text — human-readable formats such as text/plain, text/html, text/css, and text/csv.
application — everything else, from application/json and application/pdf to Office and archive formats; application/octet-stream is the generic fallback for arbitrary binary data.
image — image/png, image/jpeg, image/webp, image/svg+xml, image/avif, and more.
audio and video — media formats such as audio/mpeg, audio/ogg, video/mp4, and video/webm.
font — font/woff2, font/woff, font/ttf, and font/otf (the older EOT uses application/vnd.ms-fontobject).
model — 3D formats such as model/gltf-binary and model/stl.

When an extension is unknown

If a file's type cannot be determined, the correct generic MIME type is application/octet-stream, which tells the browser to treat the response as arbitrary binary data and download it rather than try to display it. Some extensions also have more than one valid MIME type — for example .js is officially text/javascript but application/javascript is still widely seen — and those alternates are noted next to the primary type.

Related terminology

MIME type: A standardized label of the form type/subtype (for example image/png) that identifies the format of a file or a piece of data. Also called a media type or content type.
Content-Type: The HTTP header that carries the MIME type of a request or response body, telling the recipient how to interpret the bytes that follow.
Subtype: The second half of a MIME type, after the slash, naming the specific format — png in image/png, or vnd.openxmlformats-officedocument.wordprocessingml.document in the .docx type.
application/octet-stream: The generic MIME type for arbitrary binary data. Servers use it when a file's type is unknown, which causes browsers to download rather than display it.
charset parameter: An optional addition to a text MIME type, such as ; charset=utf-8, that specifies the character encoding of the content.

Frequently asked questions

What is the MIME type for a JSON file?: The MIME type for JSON is application/json. Search for json above to confirm it, and note that JSON-LD uses application/ld+json.
What MIME type should I use for a file with no known extension?: Use application/octet-stream. It is the standard generic type for binary data, and it prompts the browser to download the file instead of trying to render it.
Why does one extension show more than one MIME type?: Some formats have several registered or historically used types. For example, .js is officially text/javascript but application/javascript is still common, and .ico appears as both image/vnd.microsoft.icon and image/x-icon. The primary, recommended type is listed first with the alternate noted beside it.
Is a MIME type the same as a file extension?: No. A file extension is a naming convention on the filesystem, while a MIME type is the format label sent over the network in the Content-Type header. Servers map extensions to MIME types, but browsers rely on the MIME type, not the extension, to decide how to handle a response.
Are my lookups sent to a server?: No. The entire MIME type table is bundled with the page and searched in your browser, so nothing you type is uploaded.

Categories

MIME Type Lookup