Validate a HTML document
HTML is a standard published by the W3C with relatively strict syntax rules. Respect for the standard to maximize the chances for optimal viewing on almost all browsers and also ensure a certain continuity in time. Using an HTML or XHTML valid permits, when developed, rapidly detect errors in syntax, tags not closed, etc.
HTML Validator
The only truly reliable tool to check the syntax of your code is the HTML Validation Service W3C accessible at:
To use this service, simply:
- Enter the page address control,
- Send the file
- Or directly copy the HTML code to validate in the field provided.
Across the options, it is possible to specify the type of document, and view the source code. The latter option is particularly useful to know where the error to be corrected.
During the correction, "start from the beginning" and think about regularly revalidate the document because some mistakes in others, and hide on the other hand some errors cause false positives.
Other Validators
Note that there are equivalents of this tool for other web standards:
For more information about the various tools , allowing you to achieve your purposes:
http://www.sitepoint.com/... 
