Html Validator

HTML Validator is a Mozilla extension that adds HTML validation inside Firefox, Mozilla. The number of errors of a HTML page is seen on the form of an icon For Firefox 56, use 0.974 (see all versions below). For Firefox 57, see Web Extensions.
What is Html Validator?
'Html Validator' is a Mozilla extension that implements HTML validation in Firefox and Mozilla. It scrutinizes HTML pages for errors and displays the count directly on the icon in the status bar. It validates HTML sent from the server as well as in the memory post Ajax execution. It offers important features such as accessibility checks based on WAI levels and also supports HTML 5 validation using W3 Online validator. Additionally, it offers various language translations for augmented user experience.
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Add-on stats

Rating: 4.26 (27)
Version: 0.9.9.5 (Last updated: 2021-08-04)
Creation date: 2004-09-11
Weekly download count: 127
Firefox on Android: No
Risk impact: High risk impact
Risk likelihood: Low risk likelihood
Manifest version: 2
Permissions:
  • <all_urls>
  • storage
  • clipboardWrite
  • webNavigation
Size: 2.78M
URLs: Website

Ranking

# 852 ▲ 8
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Other platforms

Not available on Chrome
Not available on Edge
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Add-on summary

Analyze keywords

HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla. The number of errors of a HTML page is seen on the form of an icon in the status bar when browsing.

***** See Web Extension notes below ****

The extension can validate the HTML sent by the server or the HTML in the memory (after Ajax execution).

The details of the errors are seen when looking the HTML source of the page.

The extension is based on Tidy and OpenSP (SGML Parser). Both algorithms were originally developed by the Web Consortium W3C. And now extended and improved by a lot of persons. Both algorithms are embedded inside Mozilla/Firefox and makes the validation locally on your machine, without sending HTML to a third party server.

Each algorithm has advantages and inconvenients. The program will give you the choice at startup. But mostly,

  • The SGML parser is the same program than the one running behind validator.w3.org.
  • Tidy has accessibility check for the 3 levels defined in WAI
  • W3 Online validator to validate HTML 5 pages
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User reviews

These summaries are automatically generated weekly using AI based on recent user reviews. Firefox Browser Add-ons does not verify user reviews, so some user reviews may be inaccurate, spammy, or outdated.
Pros
  • Helps catch errors while writing HTML
  • Highlights where errors are located on pages
  • Valuable for learning and writing clean HTML code
Cons
  • No longer supports CSS HTML Validator
  • Validation sometimes yields false warnings when offline
  • New version does not allow validating frames in Firefox
  • Extension options seem to be partially broken; compatibility issues with newer Firefox versions and Chrome
Most mentioned
  • Marc Gueury (developer's involvement and updates)
  • CSS HTML Validator support absence
  • Need for a clean install for some users to fix issues
  • New version requires an extra click, less immediate visibility of problems
Recent reviews
this add is good
by Firefox user 18476000, 2024-07-02
by andale, 2024-01-28
View all user reviews

Add-on safety

Risk impact

Html Validator requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk likelihood

Html Validator has earned a fairly good reputation and likely can be trusted.

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