List of default Accept values
This article documents the default values for the HTTP Accept header for specific inputs and browser versions.
Default values
These are the values sent when the context doesn't give better information.
Note that all browsers add the */* MIME Type to cover all cases.
This is typically used for requests initiated via the address bar of a browser, or via an HTML <a> element.
| User Agent | Value |
|---|---|
| Firefox 128 and later [1] | text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/png,image/svg+xml,*/*;q=0.8 |
| Firefox 92 to 127 [1] | text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8 |
| Firefox 72 to 91 [2] | text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 |
| Firefox 66 to 71 [2] | text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 |
| Firefox 65 [2] | text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 |
| Firefox 64 and earlier [2] | text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 |
| Safari, Chrome | text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8 |
| Safari 5 [3] | text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 |
| Edge | text/html, application/xhtml+xml, image/jxr, */* |
| Opera | text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/webp, image/jpeg, image/gif, image/x-xbitmap, */*;q=0.1 |
[1] The value can be set to an arbitrary string using the network.http.accept preference (about:config).
[2] The value can be set to an arbitrary string using the network.http.accept.default preference (about:config).
[3] This is an improvement over earlier Accept headers as it no longer ranks image/png above text/html.
Values for an image
When requesting an image, like through an HTML <img> element, user-agent often sets a specific list of media types to be welcomed.
| User Agent | Value |
|---|---|
| Firefox 128 and later [1] | image/avif,image/webp,image/png,image/svg+xml,image/*;q=0.8,*/*;q=0.5 |
| Firefox 92 to 127 [1] | image/avif,image/webp,*/* |
| Firefox 65 to 91 [1] | image/webp,*/* |
| Firefox 47 to 63 [1] | */* |
| Firefox prior to 47 [1] | image/png,image/*;q=0.8,*/*;q=0.5 |
| Safari (since Mac OS Big Sur) | image/webp,image/png,image/svg+xml,image/*;q=0.8,video/*;q=0.8,*/*;q=0.5 |
| Safari (before Mac OS Big Sur) | image/png,image/svg+xml,image/*;q=0.8,video/*;q=0.8,*/*;q=0.5 |
| Chrome and Edge 121 and later | image/avif,image/webp,image/apng,image/*,*/*;q=0.8 |
[1] The value can be set to an arbitrary string using the image.http.accept parameter (source).
Values for a video
Values for audio resources
When an audio file is requested, like via the <audio> HTML element, most browsers use specific values.
| User Agent | Value |
|---|---|
| Firefox 3.6 and later [1] | audio/webm,audio/ogg,audio/wav,audio/*;q=0.9,application/ogg;q=0.7,video/*;q=0.6,*/*;q=0.5 |
| Safari, Chrome | */* |
[1] See bug 489071.
Values for scripts
When a script is requested, like via the <script> HTML element, some browsers use specific values.
| User Agent | Value |
|---|---|
| Firefox [1] | */* |
| Safari, Chrome | */* |
[1] See bug 170789.
Values for a CSS stylesheet
When a CSS stylesheet is requested, via the <link rel="stylesheet"> HTML element, most browsers use specific values.
| User Agent | Value |
|---|---|
| Firefox 4 [1] | text/css,*/*;q=0.1 |
| Safari, Chrome | text/css,*/*;q=0.1 |
| Opera 11.10 | text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/webp, image/jpeg, image/gif, image/x-xbitmap, */*;q=0.1 |
| Konqueror 4.6 | text/css,*/*;q=0.1 |
[1] See bug 170789.