# Undo Note Type Changes in Bulk, When Prior Note Type Unknown **URL:** \ **Category:** Help\ **Created:** [October 9, 2026, 5:05pm UTC](https://forums.ankiweb.net/t/undo-note-type-changes-in-bulk-when-prior-note-type-unknown/71375 "2026-10-09T17:05:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![garyfields](https://avatars.discourse-cdn.com/v4/letter/g/ecd19e/32.png) [@garyfields](https://forums.ankiweb.net/u/garyfields)\ **Post date:** [October 9, 2026, 5:05pm UTC](https://forums.ankiweb.net/t/undo-note-type-changes-in-bulk-when-prior-note-type-unknown/71375/1 "2026-10-09T17:05:23Z")
**TLDR:** How can I revert all my notes to their previous note _type_, if I don’t know what the previous note type was? Is there a way to revert to the prior note type for all my notes, in bulk? **Background** I only use Anki on 1 computer, and always sync one-way to Ankiweb. I created a back-up prior to migrating note types, and my last sync was after changing note types. I have ~100K notes total, including notes from imported decks, and notes I’ve created from scratch. I organize my Anki into decks by topic. Thus, each deck has a variety of note types from various imported and created decks, all mixed together (ie: multiple types of cloze note types, different types of basic cards, and IO cards, all in one deck). One of the decks I use most is the AnKing Overhaul for Step 1 & 2 deck. For several years, I’ve added my own text and media to hundreds of AnKing notes, in the protected fields. I regularly sync to Ankihub, and have had no issues with lost data in the past. **Issue** I recently downloaded the add-on [Mayhem Card Theme Matrix](https://ankiweb.net/shared/info/1615613463). I believe my issue is not with the add-on itself, but with a lack of knowledge on my part, about how to bulk revert my notes to their prior note types. Last night, I intended to only change the aesthetics / theme, and shouldn’t have clicked “Deck Note-Type Migrator.” It was late at night and I wasn’t thinking clearly. All my note types converted to Mayhem Basic, Mayhem Cloze, or Mayhem IO. These note types don’t include the fields where I’ve added information for the past few years. I’ve spent 4 hours trying to undo this. **What I’ve Tried** I’ve found searching this forum very helpful when troubleshooting issues in the past. This is my first post, as I haven’t found a solution when searching here, online, or in the manual. I’ve tried restarting Anki, and reverting to back-ups from before I changed card types. I created a back-up immediately before migrating note types, but opening the back-up doesn’t revert the note type, only the algorithm of when a note was reviewed / edited. When I try using Notes\>Change Note Type, I get an error message saying “Please select notes from only one note type.” I could manually change each note, but don’t know which of the 53 Basic note types a particular note used to be. **Additional Questions** If I manually change the note type for each note, once the missing fields re-appear, will my media and information also return? Thank you in advance for any guidance. If this post needs to be moved, tagged, etc please let me know. May everyone who has read this far continue delighting in learning using Anki! ---
**Author:** ![ZornHadNoChoice](https://sea2.discourse-cdn.com/flex002/user_avatar/forums.ankiweb.net/zornhadnochoice/32/28874_2.png) [@ZornHadNoChoice](https://forums.ankiweb.net/u/ZornHadNoChoice)\ **Post date:** [October 9, 2026, 5:31pm UTC](https://forums.ankiweb.net/t/undo-note-type-changes-in-bulk-when-prior-note-type-unknown/71375/2 "2026-10-09T17:31:48Z")
> [@garyfields](#): > > I created a back-up immediately before migrating note types, but opening the back-up doesn’t revert the note type, only the algorithm of when a note was reviewed / edited. Are you sure you tried to restore the right back up? I just tested on AnkiDroid and restoring a back up does restore note types changes. ---
**Author:** ![garyfields](https://avatars.discourse-cdn.com/v4/letter/g/ecd19e/32.png) [@garyfields](https://forums.ankiweb.net/u/garyfields)\ **Post date:** [October 9, 2026, 6:20pm UTC](https://forums.ankiweb.net/t/undo-note-type-changes-in-bulk-when-prior-note-type-unknown/71375/3 "2026-10-09T18:20:17Z")
Thanks for your help, @ZornHadNoChoice. I tried with several back-ups before posting, but must have not gone back in time far enough. Reverting to much earlier yesterday did restore the previous note types. The perils of time travel were worth it! Back to studying I go. Sending you my appreciation, wherever you are in the world!