Multipurpose Internet Mail Extensions (MIME) types — now called IANA media types — are short labels that identify the format of a file or HTTP body. The format is `type/subtype`, e.g., `text/html`, `image/png`, `application/json`. They appear in `Content-Type` headers, multipart form uploads, email parts, and HTML ` `.

Why does the same extension sometimes have different MIME types?

Some file formats have multiple registered types, sometimes due to legacy. Example: `.js` is officially `text/javascript` (per HTML5 / RFC 9239) but historically used `application/javascript` and `application/x-javascript`. Modern browsers accept all three. When in doubt, prefer the IANA-current value.

What's the difference between `text/*` and `application/*`?

`text/*` types are human-readable formats (HTML, plain text, CSS, JavaScript). `application/*` covers everything else — binary formats (PDF, ZIP), structured data (JSON, XML when not text/), and proprietary types. The line is fuzzy: JSON used to be `application/json` even though it's technically text.

Should the server's Content-Type override the file extension?

Yes — for security and correctness. Browsers should respect the `Content-Type` header. To prevent MIME-sniffing attacks where a server sends one type but the browser guesses another, set `X-Content-Type-Options: nosniff` on every response.

What's `application/octet-stream`?

The generic 'binary blob' fallback. Browsers download it instead of trying to render. Use it for arbitrary file downloads when no specific type fits, or when you want to force a download regardless of content (combine with `Content-Disposition: attachment`).

MIME Type Lookup

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Free MIME type / file extension lookup. Search either way — type `.png` to find `image/png`, or type `application/json` to find `.json`. Covers IANA-registered media types most commonly seen in HTTP `Content-Type` headers, file uploads, and email attachments.

66 entries

Text

Extension	MIME type	Description
.txt	text/plain	Plain text
.html	text/html	HTML document
.htm	text/html	HTML document
.css	text/css	CSS stylesheet
.csv	text/csv	Comma-separated values
.js	text/javascript	JavaScript (HTML5/RFC 9239)
.mjs	text/javascript	ECMAScript module
.md	text/markdown	Markdown
.xml	application/xml	XML document
.ics	text/calendar	iCalendar
.vcf	text/vcard	vCard contact

Image

Extension	MIME type	Description
.png	image/png	PNG image
.jpg	image/jpeg	JPEG image
.jpeg	image/jpeg	JPEG image
.gif	image/gif	GIF image
.webp	image/webp	WebP image
.avif	image/avif	AVIF image
.svg	image/svg+xml	SVG vector image
.ico	image/vnd.microsoft.icon	Windows icon
.bmp	image/bmp	Bitmap image
.tiff	image/tiff	TIFF image
.heic	image/heic	HEIC image (Apple)

Audio

Extension	MIME type	Description
.mp3	audio/mpeg	MP3 audio
.wav	audio/wav	WAV audio
.ogg	audio/ogg	Ogg audio
.m4a	audio/mp4	MP4 audio
.aac	audio/aac	AAC audio
.flac	audio/flac	FLAC lossless audio
.opus	audio/opus	Opus audio
.weba	audio/webm	WebM audio

Video

Extension	MIME type	Description
.mp4	video/mp4	MP4 video
.webm	video/webm	WebM video
.mov	video/quicktime	QuickTime video
.avi	video/x-msvideo	AVI video
.mkv	video/x-matroska	Matroska video
.mpeg	video/mpeg	MPEG video
.ogv	video/ogg	Ogg video

Font

Extension	MIME type	Description
.woff	font/woff	Web Open Font Format
.woff2	font/woff2	WOFF 2.0
.ttf	font/ttf	TrueType font
.otf	font/otf	OpenType font
.eot	application/vnd.ms-fontobject	Embedded OpenType

Application

Extension	MIME type	Description
.json	application/json	JSON data
.jsonl	application/jsonl	JSON Lines
.yaml	application/yaml	YAML data
.yml	application/yaml	YAML data
.wasm	application/wasm	WebAssembly module
.bin	application/octet-stream	Generic binary blob

Document

Extension	MIME type	Description
.pdf	application/pdf	PDF document
.rtf	application/rtf	Rich Text Format
.doc	application/msword	Word 97-2003
.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document	Word (OOXML)
.xls	application/vnd.ms-excel	Excel 97-2003
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet	Excel (OOXML)
.ppt	application/vnd.ms-powerpoint	PowerPoint 97-2003
.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation	PowerPoint (OOXML)
.odt	application/vnd.oasis.opendocument.text	OpenDocument Text
.ods	application/vnd.oasis.opendocument.spreadsheet	OpenDocument Spreadsheet
.odp	application/vnd.oasis.opendocument.presentation	OpenDocument Presentation
.epub	application/epub+zip	EPUB e-book

Extension	MIME type	Description
.zip	application/zip	ZIP archive
.tar	application/x-tar	Tar archive
.gz	application/gzip	Gzip-compressed
.bz2	application/x-bzip2	Bzip2-compressed
.7z	application/x-7z-compressed	7-Zip archive
.rar	application/vnd.rar	RAR archive

Text

Image

Audio

Video

Font

Application

Document

Archive

Frequently Asked Questions

References and sources

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