More About CSS HTML Validator...

CSS HTML Validator finds problems that online validation services miss. Plus, it's more reliable, much faster, more powerful, very user configurable, protects your privacy, and has easier to understand messages. It also does things that you just can't do with online validation services.

Are you losing customers or visitors? Fix your web site & improve SEO and accessibility with CSS HTML Validator.

“I've been using HTML for years and I've learnt more in the weeks fixing my website with your validator than all the books and courses I've attended.”

“The 15 or so hours I've spent with CSE has saved hundreds, if not thousands, of hours of browser QA, support email, etc.”

“CSS HTML Validator has proven to be amazingly useful, even after I challenged myself to weed out my errors before giving the validator a look.”

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Try CSS HTML Validator now and experience how great it is to validate on your own computer!

CSS HTML Validator thoroughly checks HTML and CSS documents for a wide variety variety of problems. It includes accessibility, SEO, JavaScript, PHP, link, and spell checking.

Web developers, businesses, schools, non-profit organizations, government agencies, and students can all benefit from using CSS HTML Validator.

CSS HTML Validator validates more thoroughly and with more helpful messages than validators that are thrown-in as just another feature or as a 'second thought'. It also has options and features that you won't find elsewhere, like its unique customization features that let you edit and add your own validation messages.

CSS HTML Validator with GUI is desktop software for Microsoft Windows®, but it can also be used on a Mac or on Linux. Try it FREE for 200 validations or 30 days, whichever comes first.

A command line (console) tool for Mac (htmlval for Mac) and Linux (htmlval for Linux) is also available. This tool is based on the core validation engine in CSS HTML Validator for Windows. Try htmlval for FREE, fully functional (with no time limit) except for the maximum number of errors and warnings being locked (limited) to 10 each. The FREE limited version is also considered to be the trial version (but it has no time limit).

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Latest News About CSS HTML Validator

(February 16, 2026) CSS HTML Validator 2026/v26.01 is Now Available! - This is a minor update that includes a few updates and improvements, especially with the CSS checker.
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(January 14, 2026) CSS HTML Validator FREE Limited Versions Updated! - The htmlval FREE limited versions for Mac and Linux have been updated to v26.00. These are FREE limited versions of htmlval, a command-line console tool.
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(January 2, 2026) CSS HTML Validator 2026/v26 is Now Available! - We hope your 2025 was great! If not, then maybe the new major release of CSS HTML Validator 2026 will help cheer you up!
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(December 12, 2025) Merry Christmas / Happy Holidays! Another year will soon be history and we'd like to again wish everyone a Merry Christmas / Happy Holidays and a Happy New Year for 2026! Look for the new 2026/v26 release of CSS HTML Validator early in the new year.

(August 28, 2025) CSS HTML Validator 2025/v25.04 is Now Available! - This is a minor update that includes a few updates and improvements.
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(May 27, 2025) CSS HTML Validator 2025/v25.03 is Now Available! - This is a recommended update that includes various updates, tweaks, improvements, and bug fixes.
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