NEW! There is now a dedicated website with detailed information about running CSS HTML Validator on Wine at

"I have been using the offline Validator S.A.C. but it quit working when Apple released El Capitan. The other Apple friendly validators either don't work or are pathetic. I dusted off my Dell and upgraded my old version of CSE ... Wow! Your validator found critical errors that the S.A.C. program completely ignored."
- Michael Stewart

"I bought Parallels and Windows just to be able to run CSE HTML Validator Pro on my Mac - and it was totally worth it."
- Glen Pipkins, AllWebCo

"WINE has clearly made great progress since I first tried it some years ago, and now allows easy installation and fully functional execution of CSE HTML Validator and several other w32 tools I use with some regularity. But it's the fact that I can use CSE on an Ubuntu box that floats my boat. I can't think of another digital tool that provides me with such effective notice of my errors coupled with sophisticated learning aids."
- Walt Wheeler

"Moving from the PC to a Mac was wonderful. The ONLY software I couldn't find on the Mac was CSE HTML Validator, therefore I bought Virtual PC for the Mac just so I could run CSE. It is the best HTML/XHTML editor and validation tool on the market, and the only one I recommend to fellow Web professionals and my students."
- Dr. Tim Gottleber, author of Even More Excellent HTML and BulletProof Unix

"I bought CSE HTML Validator Pro almost 6 months ago, and have since switched to a near-full-time Linux user. However, I've managed to find an equivalent or better product for every Windows-only product on Linux...except CSE HTML Validator. CSE HTML Validator remains the only stumbling block that keeps me going back to Windows."
- Brian Deragon

Run CSS HTML Validator on a Mac or Linux

We are often asked if there is a Mac or Linux version of CSS HTML Validator available. We do not have native Linux, Mac, or Unix version but you can still run CSS HTML Validator using a method described below.

Most of the methods (except Wine and CrossOver) require running Windows in a virtualized environment, which means you'll need a Windows license (the exception is Wine).

Wine (Mac OS X & Linux)

Wine is the recommended way to run CSS HTML Validator on a Mac or Linux if you do not already have a virtualized Windows machine and do not want to buy a Microsoft Windows® license.

Wine is a compatibility layer capable of running many (but not all) Windows applications on several POSIX-compliant operating systems, such as Linux, Mac OS X, & BSD. Wine also doesn't require the purchase of Microsoft Windows unlike Parallels Desktop, Boot Camp, VirtualBox, and other OS virtualization products. You'll also save gigabytes of disk space by not needing a virtualized Windows environment.

CSS HTML Validator 2018 reportedly runs well (used for over a year) with Wine 3.0 on Linux (Ubuntu 18.04).

CSS HTML Validator 2019 (v19.01) was tested by us to run well on Linux Mint 19.1 (based on Ubuntu 18.04).

Note: If you encounter a clipboard registration issue (that may cause the system to become unresponsive and require a system reboot) then you may be able to resolve it using an alternate method of registration. If you encounter this issue then please contact us.

Note that CSS HTML Validator v19.01 or above is recommended (but not required) when running under Wine because tweaks have been made for Wine.

What will not or may not work with Wine?

Download Wine here (new window). If given the option during the installation to support 64-bit programs then please choose it in order to support CSS HTML Validator 2019/v19+.

If you're using Mac OS X then you may also want to see Installing Wine on Mac OS X (new window).

Forum topic: Running CSS HTML Validator on Mac & Linux

CrossOver (Linux, Mac, & Chrome OS)

CrossOver is a polished version of Wine provided by CodeWeavers. CrossOver makes it easier to use Wine.

Parallels Desktop for Mac

Use Parallels Desktop to run the Windows OS and Windows applications on your Mac.

Boot Camp for OS X

Use Boot Camp to boot into multiple operating systems including Windows. It's available in Mac OS X v10.5 Leopard or higher. See also this wikipedia article.

VirtualBox (Linux, Mac, Solaris)

You can use VirtualBox (FREE) to run Windows on a Linux, Macintosh or Solaris host. This will let you run CSS HTML Validator and other Windows programs.

Note that while VirtualBox is free, you'll still need a license for Windows which is not free.

VMware Fusion for Intel based Mac

Intel based Macs can also use VMware Fusion to run Windows.

Other Solutions

There are also other solutions from various vendors for running Windows programs on other host platforms.

And Don't Forget...

NEW! There is now a dedicated website with detailed information about running CSS HTML Validator on Wine at