HTML Validator icon

HTML Validator

by Marc Gueury · gueury.com · Developer Tools
FeaturedEstablished publisherManifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

Add HTML Validator in Developer Tools

Users
30K
0 in 30 days
Rating
3.5 / 5
unchanged in 30 days
Ratings
37
0 in 30 days
Store rank
#4,896
#4,249 among extensions
Version
0.9.9.8
updated 28 Dec 2022

Users

monthly, 3 years
10K25K40KAug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 30,000 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years
102438Aug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 37 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About HTML Validator

This is the of HTML Validator extension for Chrome Manifest V3. It checks the code, syntax, of your HTML 5 pages. HTML Validator for Chrome is a browser extension that adds HTML validation inside Developer Tools of Chrome. The number of errors of a HTML page is seen with an icon in the browser status bar. The details is seen in the developer tools. The extension is based on HTML Tidy. The algorithm was originally developed by the Web Consortium W3C. The algorithm is embedded inside your browser and makes the validation locally on your machine, without sending HTML to a third party server. HTML Tidy is a helpful program that tries to help people to correct their HTML errors. It finds HTML errors and classifies them in 3 categories: * errors: HTML errors that Tidy cannot fix or understand. * warnings: HTML errors that Tidy can fix automatically * (optional) accessibility warnings: HTML warnings for the 3 priority levels defined in W3c WAI There is also an automatic "Clean up" button that will do his best to propose you a cleaned version of your page, without errors. For any question, mail me at mgueury@skynet.be or log a bug in: > https://gitlab.com/mgueury/html_validator/issues

Growth

WindowUsersChangeRatingsRating
7 days0+0.0%00.00
30 days0+0.0%00.00
6 months−10K−25.0%−1+0.07
1 year−10K−25.0%0+0.11

Chrome Web Store search rankings

Where HTML Validator appears when people search the store, with the 30 day change
Search phrasePosition30 days
html#5−4
algorithm#82−43
error#98−45

Version history

5 versions recorded
0.9.9.828 Dec 2022
0.9.9.623 Dec 2021
0.9.9.515 Aug 2021
0.9.9.423 Jul 2021
0.9.8.828 May 2018

Details

Category
Developer Tools
First seen
28 May 2018
Size
2.5 MB
Languages
en-US
Pricing
Free
Support
gueury.com
Extension ID
mpbelhhnfhfjnaehkcnnaknldmnocglk

Permissions and risk

Moderate riskimpact 3, likelihood 1
Permissions
storageactiveTabclipboardWritewebNavigationscripting
Site access
<all_urls>
Can read and change data on every website you visit.

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