You can also quickly delete all WordPress Meta Fields using MySQL or phpMyAdmin. This method is only recommended for more advanced users.
Login to the cPanel dashboard of your WordPress hosting account. Under the database section, click on phpMyAdmin.

Inside phpMyAdmin, you will need to locate your WordPress database. You will see a page like this showing all your WordPress database tables.

• Post Meta

Check the box next to  wpprefix_postmeta table. The name of your posts tables may differ depending on the table prefix you choose during your WordPress installation.

You can delete post meta using meta_key and meta_value.
After selecting the checkbox of post meta fields click on the delete button.
PhpMyAdmin will now show you a warning asking if you really want to delete those fields.

That’s all, this post helped you learn how to easily delete post meta fields in WordPress

• User Meta

  

Check the box next to  wpprefix_usermeta table. The name of your posts tables may differ depending on the table prefix you choose during your WordPress installation.

You can delete user meta using meta_key and meta_value.
After selecting the checkbox of user meta fields click on the delete button.
PhpMyAdmin will now show you a warning asking if you really want to delete those fields.

That’s all, this post helped you learn how to easily delete user meta fields in WordPress

• Comment Meta

Check the box next to  wpprefix_commentmeta table. The name of your posts tables may differ depending on the table prefix you choose during your WordPress installation.

You can delete comment meta using meta_key and meta_value.
After selecting the checkbox of comment meta fields click on the delete button.
PhpMyAdmin will now show you a warning asking if you really want to delete those fields.

That’s all, this post helped you learn how to easily delete post meta fields in WordPress

That’s all, we hope this article helped you learn how to easily delete all meta fields in WordPress.