
Because there can only be one H1 per page, Accessible Theme automatically blocks you from including another inside your post. Headings that skip levels (e.g. putting an H3 before an H2) will also be flagged and prevented.
Another very common accessibility error is forgetting to insert alt text with an image. Accessible Theme forces you to add alt text or you will not be able to publish a post or page.

Accessible Theme even makes adding iframe titles to YouTube videos easy. Once you paste the embed code, you’ll be prompted to enter a title into the notification box and that title will automatically be embedded into the code.

Text transcripts are even taken care of for you. As soon as you upload audio or video, you’ll be prompted to enter a text transcript. Just paste it into the Accessible Theme notification box and you’ll be all set.

And if you miss a text transcript, you’ll get an error alert above your post/page composer.

There are more notifications and alerts but the point is Accessible Theme makes it extremely difficult on you to upload inaccessible content.
Not only will is Accessible Theme accessible out of the box but it prevents user error.