We'll definitely add this if Tumblr's Mass Post Editor (the back end API of which we use here) gets an unprivate feature, or at least if its back end does! Send a suggestion in to https://www.tumblr.com/support if you'd like that. If not, the only way we could make a mass unprivate feature would process one post per second instead of a hundred, which is of course way slower.

Though I suppose it would still be a useful feature no matter how slow it was—one might have few posts or be fine leaving it to run overnight, and there's no other way to filter private posts by tag at all, so it's not like there's an alternative.

Yeah, I didn't realize that private post aren't technically publushed yet until recently so selecting them that way wouldn't really work in the same way mass privater works. Having that option in the mass post editor would be nice so I'll definitely email them about it. Even if it'll work through it one by one, as long as I don't have to be sitting there doing it myself I'll be fine with any solution~.

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