INSTALLATIONThe add-on that is downloadle here is not signed.
To install, the non-signed version of the add-on, you need to use
Firefox Developer edition.
With Firefox 43, all extensions have to be signed by Firefox to be installled on a Firefox Production version.
Developer Edition and Nightly versions:
- Download Firefox Developer Edition here : https://www.mozilla.org/en-US/firefox/channel/#developer
- Type "about:config" into the URL bar in Firefox in the Search box (screen screenshot)
- Search for "required"
- Double-click on "xpinstal.signatures.required" and set it to false.
- Download HTML Validator Extension (below)
For more info see here.
FIREFOX 44.0x or later Choose your platform :
FIREFOX 10.0x or later Choose your platform :
Thanks to EclipseChasers2 and Tom for the compilation of the Linux64
and MacOsX versions (see Forums)
FIREFOX 9.0x Choose your platform :
FIREFOX 8.0x Choose your platform :
FIREFOX 7.0x Choose your platform :
FIREFOX 6.0x Choose your platform :
FIREFOX 4.0x or 5.0.x Choose your platform :
FIREFOX 4.0.x ONLY Choose your platform :
The extension XPI is now 2.0 Mb big ... The SGML
parser is quite complex :-) But seems to work really well. The
validation for the biggest pages I saw are below the 1/100 sec for both
The new version adds the following new features:
For additional questions, there is a forum : http://www.htmlpedia.org/phpBB/
- Due to Numerous changes due to Firefox 4.0, the
extension 0.9 is compatible only with Firefox 4.0
- The browser icon is in the add-on bar (new name for
the status -bar). The add-on bar is hidden by default in FF
- This means too that all platforms binaries will need
to be recompiled.
Look the source and the forum if you want to help on the
- To enable HTML 5 validation, it is possible to
validate page with W3c Online.
This works in the page source only to avoid to overload the W3c server.
- It is possible to use CSE HTML Validator as
algorithm if the program is installed. You will need version
10 and later.
Screenshot 1: Html Validator
icons depending of the algorithm used.
Screenshot 2: Html Validator (validation by Tidy)
Screenshot 3: Html Validator (validation by SGML Parser)
Screenshot 4/5: The same page validated by
(compare the errors with screenshot 3)