Document.xmlVersion

Obsolete since Gecko 10.0 (Firefox 10.0 / Thunderbird 10.0 / SeaMonkey 2.7)
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

Returns the version number as specified in the XML declaration (e.g., <?xml version="1.0"?>) or "1.0" if the declaration is absent.

This attribute was never really useful, since it always returned 1.0, and has been removed in DOM Level 4. As such, Firefox 10 no longer implements it. Its primary use in the past was to detect whether or not the document was being rendered as XML rather than HTML. To detect this, you can create an element with its name in lower case, then check to see if it gets converted into all upper case (in which case the document is in the non-XML HTML mode):

if (document.createElement("foo").tagName == "FOO") {
  /* document is not XML */
}

Specifications

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic support
DeprecatedNon-standard
Chrome Full support YesEdge ? Firefox No support NoIE ? Opera ? Safari ? WebView Android Full support YesChrome Android Full support YesEdge Mobile ? Firefox Android No support NoOpera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Non-standard. Expect poor cross-browser support.
Non-standard. Expect poor cross-browser support.
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.

Document Tags and Contributors

Contributors to this page: fscholz, teoli, kscarfone, Sheppy, Jürgen Jeka, Nickolay, Hsivonen, Brettz9
Last updated by: fscholz,