Writing HTML is fine, but what if something goes wrong, and you can't work out where the error in the code is?This article will introduce you to some tools that can help you find and fix errors in HTML.This webpage takes an HTML document as an input, goes through it, and gives you a report to tell you what is wrong with your HTML.To specify the HTML to validate, you can give it a web address, upload an HTML file, or directly input some HTML code. This should give you a list of errors and other information.The latest development code for the CSS Validator is available through the Git Hub repository.For a visual representation, see the CSS Validator Sequence Diagram, which is available in png, graffle and svg formats.When writing code of some kind, everything is usually fine, until that dreaded moment when an error occurs — you've done something wrong, so your code doesn't work — either not at all, or not quite how you wanted it to.For example, the following shows an error reported when trying to compile a simple program written in the Rust language.
The image should be used as a link to re-validate the document.
The error messages are usually helpful, but sometimes they are not so helpful; with a bit of practice you can work out how to interpret these to fix your code.
Let's go through the error messages and what they mean.
So you can see from the above example that you really want to make sure your HTML is well-formed! In a small example like the one seen above, it is easy to search through the lines and find the errors, but what about a huge, complex HTML document?
The best strategy is to start by running your HTML page through the Markup Validation Service — created and maintained by the W3C, the organization that looks after the specifications that define HTML, CSS, and other web technologies.