Browser extensions
These are free to use, but please read the licence before downloading them.
They are all fully tested on Windows, macOS and Linux, and to work they need Total Validator Basic or Pro to be installed.
Documentation: Chrome & Firefox
Note: If you have problems installing the Firefox extension, try restarting Firefox. Alternatively, right mouse click on the link above, save the .xpi
file to your computer, then drag this onto Firefox.