Is `text/javascript` or `application/javascript` correct for JS files?

Both work, but the WHATWG HTML spec officially recommends `text/javascript` when serving JavaScript over HTTP. `application/javascript` is widely supported and you'll see it in older configurations.

What's the difference between `image/jpeg` and `image/jpg`?

Only `image/jpeg` is the registered IANA type. `image/jpg` is a common misspelling — most browsers tolerate it but tools and HTTP caches may not.

When should I use `application/octet-stream`?

Use it for arbitrary binary data when no more specific type fits, or to force the browser to download the file instead of displaying it. Pair with a `Content-Disposition: attachment` header.

MIME Type Lookup

Developer

Practical reference of file extensions and the MIME / media types HTTP servers and the browser-side `Content-Type` header use to identify them. Filter by category — application, audio, font, image, text, video, multipart — or search across extension, MIME string and description at once.

—

Extension	MIME type	Description
.json	application/json	JSON data interchange format (RFC 8259).
.xml	application/xml	XML data — use text/xml for human-readable, application/xml for machine-only.
.pdf	application/pdf	Portable Document Format.
.zip	application/zip	PKZIP archive.
.gz	application/gzip	Gzip-compressed file.
.tar	application/x-tar	Tape archive (Unix).
.7z	application/x-7z-compressed	7-Zip archive.
.rar	application/vnd.rar	RAR archive.
.js	application/javascript	JavaScript source — text/javascript is preferred in HTTP per the WHATWG.
.wasm	application/wasm	WebAssembly binary module.
.bin	application/octet-stream	Arbitrary binary data — the default for unknown types.
.doc	application/msword	Microsoft Word 97-2003.
.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document	Microsoft Word (Office Open XML).
.xls	application/vnd.ms-excel	Microsoft Excel 97-2003.
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet	Microsoft Excel (Office Open XML).
.ppt	application/vnd.ms-powerpoint	Microsoft PowerPoint 97-2003.
.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation	Microsoft PowerPoint (Office Open XML).
.odt	application/vnd.oasis.opendocument.text	OpenDocument Text (LibreOffice / OpenOffice).
.mp3	audio/mpeg	MPEG-1 Audio Layer 3.
.wav	audio/wav	Waveform Audio File Format.
.ogg	audio/ogg	Ogg container with Vorbis/Opus.
.flac	audio/flac	Free Lossless Audio Codec.
.aac	audio/aac	Advanced Audio Coding.
.m4a	audio/mp4	AAC inside an MP4 container.
.webm	audio/webm	WebM audio (Vorbis/Opus).
.ttf	font/ttf	TrueType font.
.otf	font/otf	OpenType font.
.woff	font/woff	Web Open Font Format.
.woff2	font/woff2	Web Open Font Format 2 — better compression than woff.
.jpg	image/jpeg	JPEG image — use this for `.jpg` and `.jpeg`.
.png	image/png	Portable Network Graphics.
.gif	image/gif	Graphics Interchange Format — supports animation.
.webp	image/webp	WebP — smaller than JPEG/PNG, supports transparency and animation.
.avif	image/avif	AV1 Image File Format — even smaller than WebP.
.svg	image/svg+xml	Scalable Vector Graphics — XML-based vector format.
.ico	image/vnd.microsoft.icon	Windows icon — also commonly served as image/x-icon.
.bmp	image/bmp	Windows Bitmap.
.tiff	image/tiff	Tagged Image File Format.
.heic	image/heic	High Efficiency Image Format (iOS default).
.txt	text/plain	Plain text — the default for unknown text.
.html	text/html	HyperText Markup Language.
.css	text/css	Cascading Style Sheets.
.csv	text/csv	Comma-Separated Values.
.tsv	text/tab-separated-values	Tab-Separated Values.
.md	text/markdown	Markdown source.
.yaml	application/yaml	YAML document — older text/x-yaml is still seen in the wild.
.ics	text/calendar	iCalendar event/calendar data (RFC 5545).
.vcf	text/vcard	vCard contact data.
.mp4	video/mp4	MPEG-4 video (H.264/H.265 + AAC).
.webm	video/webm	WebM video (VP8/VP9 + Vorbis/Opus).
.mov	video/quicktime	QuickTime Movie.
.avi	video/x-msvideo	Audio Video Interleave.
.mkv	video/x-matroska	Matroska Multimedia Container.
.mpeg	video/mpeg	MPEG-1/2 video.
—	multipart/form-data	HTML form upload with files — used by <form enctype="…">.
—	multipart/byteranges	Multiple ranges from a single resource — Range request responses.
—	multipart/mixed	Several body parts of different content types.

How to use

Type a file extension (`.zip`), MIME type (`application/json`), or keyword (`compressed`) into the search box.
Pick a category chip to narrow down — e.g. just image types when you're configuring uploads.
Click the copy button next to any row to copy the MIME string.

Frequently asked questions

Is `text/javascript` or `application/javascript` correct for JS files?: Both work, but the WHATWG HTML spec officially recommends `text/javascript` when serving JavaScript over HTTP. `application/javascript` is widely supported and you'll see it in older configurations.
What's the difference between `image/jpeg` and `image/jpg`?: Only `image/jpeg` is the registered IANA type. `image/jpg` is a common misspelling — most browsers tolerate it but tools and HTTP caches may not.
When should I use `application/octet-stream`?: Use it for arbitrary binary data when no more specific type fits, or to force the browser to download the file instead of displaying it. Pair with a `Content-Disposition: attachment` header.