What is the MIME type of .jpg files?
The MIME type (media type) for JPEG image files with the .jpg extension is image/jpeg. The same type is used for .jpeg. Note the type is image/jpeg, never image/jpg. The same type covers .jpeg, .jpe and .jfif.
Content-Type header
Content-Type: image/jpegServer configuration
| Server | Configuration |
|---|---|
Nginx (mime.types or types {}) | image/jpeg jpg; |
Apache (.htaccess) | AddType image/jpeg .jpg |
IIS (web.config) | <mimeMap fileExtension=".jpg" mimeType="image/jpeg" /> |
| Node.js / Express | res.type('jpg') or res.setHeader('Content-Type', 'image/jpeg') |
| Amazon S3 | Set Content-Type: image/jpeg on the object (metadata), or pass --content-type image/jpeg to aws s3 cp |
Should .jpg files be compressed?
No. JPEG image files are already compressed internally, so gzip or Brotli would waste CPU and barely reduce — sometimes even increase — the size. Leave image/jpeg out of your compression configuration.
Why the MIME type matters
Browsers decide what to do with a response — render, run, play or download — from the Content-Type header, not the file extension. With X-Content-Type-Options: nosniff, a wrong type causes stylesheets and scripts to be blocked outright. For uploads, never trust the type sent by the client; check the file’s content (its magic bytes) on the server.
Frequently asked questions
What is the MIME type for .jpg?
image/jpeg.How do I set the Content-Type for .jpg in Nginx?
image/jpeg jpg; is listed in the types block (usually in /etc/nginx/mime.types) and reload Nginx.