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 Comment
Firefox text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
 
This value can be modified using the network.http.accept.default parameter.
Safari, Chrome

application/xml,application/xhtml+xml,text/html;q=0.9, text/plain;q=0.8,image/png,*/*;q=0.5

source
Safari 5

text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

This is an improvement over earlier Accept headers as it no longer ranks image/png above text/html
Internet Explorer 8 image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, application/x-shockwave-flash, application/msword, */* See IE and the Accept Header (IEInternals' MSDN blog).
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  

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 Comment
Firefox */* (since Firefox 47)
image/png,image/*;q=0.8,*/*;q=0.5 (before)
This value can be modified using the image.http.accept parameter.
Safari */*  
Chrome image/webp,image/*,*/*;q=0.8 Was */* before the support for webp
Internet Explorer 8 or earlier */* See IE and the Accept Header (IEInternals' MSDN blog)
Internet Explorer 9 image/png,image/svg+xml,image/*;q=0.8, */*;q=0.5 See Fiddler is better with Internet Explorer 9 (IEInternals' MSDN blog)

Values for a video

When a video is requested, via the <video> HTML element, most browsers use specific values.

User Agent Value Comment
Firefox earlier than 3.6 no support for <video>  
Firefox 3.6 and later audio/webm, audio/ogg, audio/wav, audio/*;q=0.9, application/ogg;q=0.7, video/*;q=0.6; */*;q=0.5 See bug 489071
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 Comment
Firefox 3.6 and later audio/webm,audio/ogg,audio/wav,audio/*;q=0.9,application/ogg;q=0.7,video/*;q=0.6,*/*;q=0.5 See bug 489071
Safari, Chrome ?  
Internet Explorer 8 or earlier no support for <audio>  
Internet Explorer 9 ?  

Values for scripts

When a script is requested, like via the <script> HTML element, some browsers use specific values.

User Agent Value Comment
Firefox */* See bug 170789
Safari, Chrome */*  
Internet Explorer 8 or earlier */* See IE and the Accept Header (IEInternals' MSDN blog)
Internet Explorer 9 application/javascript, */*;q=0.8 See Fiddler is better with Internet Explorer 9 (IEInternals' MSDN blog)

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 Comment
Firefox 4 text/css,*/*;q=0.1 See bug 170789
Safari 5 text/css,*/*;q=0.1  
Internet Explorer 8 or earlier */* See IE and the Accept Header (IEInternals' MSDN blog)
Internet Explorer 9 text/css See Fiddler is better with Internet Explorer 9 (IEInternals' MSDN blog)
Chrome 12 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  

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 Contributors to this page: Sheppy, AutoSponge, fscholz, teoli
 Last updated by: Sheppy,