Web Validation Tools
Validation areas:
- HTML
- CSS
- Accessibility
List of tools from the W3C.
HTML
- W3C HTML Validator
- Validates based on DTD. By URL and File Upload - offers extended interface options.
- CSE HTML Validator
- Application that provides real-time feedback on outputted markup while browsing. Very useful when working with scripting languages like JSP behind a firewall, or in an application that requires a login. It offers a bunch of additional information about CSS and Accessibility.
- Firefox Web Developer Tool Bar
- A great utilities for developers, including the option to validate CSS and HTML locally.
- Firefox HTML Validator
- Shows errors and warnings during each page load on the status bar. It shows additional information when viewing the source, including row highlighting of problems.
- Web Design Group
- Very similar to W3C validator, but includes a few extra warnings. Validates based on DTD. By URL only.
An interesting note from WDG...
The two validators [W3C and WDG] differ significantly from other checking tools such as Weblint and CSE 3310 HTML Validator. (Despite its name, the latter is not a true "validator.") The two online validators check documents against a document type definition--a published, machine-readable document that facilitates an objective check of syntax against HTML standards. On the other hand, lints are subjective; they provide a more cursory syntax check while adding stylistic checks, such as warning about poorly supported features. Lints are useful tools, but they are not substitutes for HTML validation.
CSS
- W3C CSS Validator
- Validates by URL (HTML with CSS or CSS only), or by file upload.
Accessibility
- Bobby
- Section 508/WCAG reporting per URL. Desktop application also available.