HTML Tutorial
HTML - Introduction HTML - Basic HTML - Structure HTML - Element HTML - Attributes HTML - Headings HTML - Paragraphs HTML - Styles HTML - Formatting HTML - Phrase Tags HTML - Quotations HTML - Comments HTML - Colors HTML - CSS HTML - Links HTML - Images HTML - Tables HTML - List HTML - Inline elements HTML - Block elements HTML - Classes HTML - Id HTML - Javascript HTML - File Path HTML - Iframe HTML - Responsive HTML - Computer Code HTML - Head tag HTML - Events HTML - Url Encoding HTML - Entities HTML - Validation
HTML Forms
HTML - Forms HTML - Form Elements HTML - Input types HTML - Input Attributes
HTML5
HTML5 - Introduction HTML5 - New Elements HTML5 - Semantics HTML5 - Style Guide
HTML Media
HTML - Video HTML - Audio HTML - Embed Multimedia
HTML Graphics
HTML - Canvas HTML - SVG
HTML APIs
HTML - Geolocation HTML - Drag & drop HTML - Web Storage HTML - Web Workers
HTML References
HTML - Tag Reference HTML - Tag by Category HTML - Attributes HTML - Global Attributes HTML - Events HTML - Language Codes HTML - Country Codes HTML - URL Encoding HTTP Methods HTTP Status Codes <input> types

HTML Validation

So you’ve written a few HTML pages, and they seem to display ok to you, but there are a few things not quite right with them. What is the best way to start finding out what is wrong, and ensure that these pages (and any future pages you write) will be displayed properly across browsers, with no errors?

Validation is the answer! There are many tools available, from the W3C and other places, that allow you to validate the code on your sites.


Validator.nu

A new-school validator that validates HTML5, ARIA, SVG 1.1 and MathML 2.0: it goes through the entire document pointing out places where your markup doesn’t follow that doctype correctly (ie where there are errors). This is the one we recommend if you are using the HTML5 doctype, like we do throughout most of this course.

To use this validator for HTML5, you need to choose text Field, then copy and paste your HTML5 code.

validator.nu

Visit: https://validator.nu/


W3C Markup Validator

The W3C Markup Validator checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc. This validator is part of Unicorn, W3C's unified validator service.

To use this validator for HTML5, you need to use More Options and select Document Type as HTML5 (experimental) as shown below.

w3c markup validator

Visit: https://validator.w3.org/

There are many other validator available, you can try them if you wish.