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 92 and later [1] | text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8 |
| Firefox 72 to 91 [1] | text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 |
| Firefox 66 to 71 [1] | text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 |
| Firefox 65 [1] | text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 |
| Firefox 64 and earlier [1] | 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 [2] | text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 |
| Internet Explorer 8 [3] | image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, application/x-shockwave-flash, application/msword, */* |
| 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] This value can be modified using the network.http.accept.default parameter.
[2] 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 92 and later [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 | image/avif,image/webp,image/apng,image/*,*/*;q=0.8 |
| Internet Explorer 9 | image/png,image/svg+xml,image/*;q=0.8, */*;q=0.5 |
| Internet Explorer 8 or earlier source | */* |
[1] This value can be modified using the image.http.accept parameter (source).
Values for a video
When a video is requested, via the <video> HTML element, most browsers use specific values.
| User Agent | Value |
|---|---|
| Firefox 3.6 and later | video/webm,video/ogg,video/*;q=0.9,application/ogg;q=0.7,audio/*;q=0.6,*/*;q=0.5 |
| Firefox earlier than 3.6 | no support for <video> |
| Chrome | */* |
| Internet Explorer 8 or earlier | no support for <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 | */* |
| Internet Explorer 8 or earlier | no support for <audio> |
| Internet Explorer 9 | ? |
[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 | */* |
| Internet Explorer 8 or earlier [2] | */* |
| Internet Explorer 9 | application/javascript, */*;q=0.8 |
[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 |
| Internet Explorer 8 or earlier [2] | */* |
| Internet Explorer 9 | text/css |
| 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.