Is there a plugin for Firefox to validate HTML 5?
I've always used this, but if my webpage has a <!DOCTYPE HTML> doctype it complains about it not having a doctype at all.
I specifically would like one similar to the one I linked, where the verification happens on your computer and instantaneous and automatic, without needing to send any data to a third-party server and then wait for a reply.
Thomas BoniniThomas Bonini
4 Answers
This is the best one I found so far:
https://github.com/rogerjohansson/html5validator (see Downloads for an xpi)
You should not use the validator.nu online service with it, since it causes a DoS attack on the online service, and you will probably be banned from using the service as a countermeasure (see https://github.com/rogerjohansson/html5validator/issues/6). The cool thing is, it does not send the URL to the validator, but the HTML data directly; this means that local sites or password-protected sites can also be checked.
Validation can be turned on automatically, by a domain-whitelist or by clicking the validator item.
You can and should up your own validator.nu-instance (at least on Linux and Mac OS X) - see this. You would then have a locally-running validator and can even check sites without an Internet connection by filling in http://localhost:8888/ (the default address of the local validator instance) into the Validator URL of the addon.
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To give credits: I have the information above from Validating HTML5 with validator.nu and the HTML5Validator Extension for Firefox.
MarkusMarkus
On the Web Developer add-on, https://addons.mozilla.org/en-US/firefox/addon/60, if you use 'Tools' > 'Display Page Validation' it will show a bar at the top validating the page source code. This is done via the W3C validator, but without you having to navigate there.
It is a shame the HTML Validator has no plans as of yet to incorporate HTML5 until at least version 0.9.
Tom
This says it will do it: https://addons.mozilla.org/en-US/firefox/addon/2318 and I found this also: http://html5.validator.nu/
bpartchbpartch
You can validate HTML5 at the following site:
Make sure on the options that you select the HTML5 document type.
santoshthakur100santoshthakur100
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Posted by3 years ago
Archived
Disable HTML5 player - Firefox
Hi all..
I've encountered a problem with Youtube via Firefox (latest version), where on a few videos, I can't select any format above 360p.
Viewing the same video in Chrome, I can choose HD versions.
To test, I installed a Firefox addon that forces the browser to use the flash player, and that sort of fixes it.. it lets me choose the higher resolutions, but it also seems to cause the player to act goofy where I sometimes have to refresh the video when I first load, to get it to play at all.
I've searched Google and keep seeing references to go to https://www.youtube.com/html5 and disable the HTML5 player.
But when I go there, all I see if a confirmation that yes, my browser is using the HTML5 player, but I don't see where to turn that off.
Am I just being blind, or is there somewhere else to disable the HTML player?
100% Upvoted
sohogenerous – 2019