Validators and assertions
| Shortcut assertion | Validator |
|---|---|
| h1 | Allow only one H1 |
| og | Required set of Open Graph meta tags |
| title | There must be a title tag and it must be no longer than 55 characters |
| alt | All images must have an alt tag |
| lang | The HTML opening tag should have a valid lang attribute |
| vp | There should be a viewport meta tag with width and initial-scale set |
| atxt | Links should have a descriptive text |
| auvid | No autoplaying videos, they bad for accessibility reasons and really annoying |
| mdesc | There should be a description meta tag with content between 50 and 160 characters |
| canon | It is a good practice to have a canonical link on your pages |
If you have an idea for a new validator, be sure to open an issue!