How to mass-delete MOST of my SMS texts

[Android Central Question]

Due to several problems involving dead phones and restored backups, I've found myself with two copies each of my 25,000 SMS messages, plus a handful of unique messages that have come in during the last couple days. I want to delete every message older than three days so that I can restore my most recent backup to get just a single copy of all the old messages. I really don't want to delete the last few days of messages, though.

I have several texting apps that allow me to multi-select individual messages, but they all require clicking on each individual messages, which isn't practical for bulk deletion. Is there a texting app that allows shift-clicking (so to speak) to select every message in a range? Or one that allows me to select all messages, and then deselect just a few recent ones prior to deletion?

I've tried Textra, Android Messages, and the stock Samsung messaging app. I'm running a Galaxy S6 with android 7.0.

 

[Obi-Wan-YJ]

OK, I figured it out. It turns out that the Samsung Messages app has exactly this functionality, but it's hidden by a crappy user interface.
When you're viewing the messages in a thread, WITHOUT any messages selected, you go up to the top right and click the hamburger icon and then the "delete" icon. This, then, puts in into the multi-select mode. At the top left, there's an "all" box that you can check to select every messages in the thread. From there, you can deselect the handful of messages that you don't want to delete before finally tapping the word "delete" in the upper right corner. It gives you a confirmation prompt before deleting.

 

[B. Diddy]

Thanks for letting us know the solution!