When you have a site that you are upgrading and revising, you may want to delete hundreds or thousands of old posts that aren’t high quality or just aren’t relevant any more. I have some aged sites that have thousands of auto generated posts that need cleaning up. Most WordPress users know that to delete posts, just select the posts you want to delete and then hit move to trash, and update, and the list of checked posts will be deleted.
The problem is that the default WordPress posts page only shows about 20 posts at a time. So bulk deleting a thousand posts would be very tedious and time consuming. I have actually spent a considerable amount of time doing manual bulk deletes, then I realized there has got to be an easier way. My first inclination was to go into phpMyAdmin and do a bulk delete of the posts. Fortunately, I discovered there is a much easier way.
Instead of manually doing bulk deletes, 20 posts at a time, all we have to do is go into screen options and change the number of posts showing from 20 to 999 or some other large increment appropriate for the amount of posts we wish to delete. Just remember, if you use the title check box to select all of the posts to delete, deselect any posts that you may want to keep. Also, keep in mind that the screen option menu is contextual, so the show posts number option is under screen options when you are in the all posts screen.
If you are concerned about broken links from deleting the old posts you could use some type of redirect plugin such as link juice keeper. With the current push towards better quality sites, cleaning up and revising old posts can be a good way to give your site a lift.