What Does "Mass Editor" Mean in Tumblr?by Geoff Whiting
The “Mass-editor” button available on your Tumblr's dashboard allows you to edit or modify multiple blog posts simultaneously. You can delete multiple posts at one time with the editor. The editor also supports adding and editing tags on your posts. Tumblr uses tags to sort content and allow users to search for specific types of content, so mass editing the content will allow you to change the audience that your posts reach.
Tumblr has added a “Mass-editor” button to your blog’s dashboard that allows you to access its “Mega-Editor” tool. The button will take you to your own Mega-Editor page that provides options to delete posts, edit tags or add tags. Click on all of the posts you want to edit and then click the button for the action you want to take. The site will ask you to confirm the choice before it makes any changes, such as deleting posts or tags.
Add and Edit Tags
To add or edit tags on multiple posts, navigate to your dashboard and click the “Mass-editor” button; some Tumblr users see this as a "Launch Mass Post Editor" link. Select all of the posts you want to edit; selected posts will have a check mark in the top-right corner. Click either the “Add Tags” or “Edit Tags” button and click on the dialog box that appears. Here you can add or remove tags for all of these posts. You must separate tags with a comma. Click the “Add Tags” button at the bottom of this dialog box to finish adding or editing the tags for your posts.
The Mega-Editor tool can only edit posts you created, so reblogged items will not show up in your list of available posts. It also does not show other people's content that you have interacted with on the service. Some users have found that posts created on mobile devices or through its email publishing do not show up on their Mega-Editor screen. As of December 2013, the Mega-Editor is still in its beta testing phase, so support and fixes may be under development.
One benefit to the Mega-Editor tool is that you can quickly delete content from your Tumblr blog. The tool’s page shows all of a month’s posts in quick thumbnail format, so you can select them all from the same screen instead of having to navigate page-by-page and delete items individually. You can also navigate to any previous month since you joined Tumblr, making it easy to delete old posts that mention people, activities or opinions you no longer want to be associated with.