I have this folder named .mixin.out in my .minecraft folder. I saw this post on Reddit, but it lies directly in my .minecraft folder. The only things I have added recently was a datapack and a the Faithful 32x32 texture pack. Should I delete this folder? It contains a csv file which is empty and text file that says Mixin Implementation Report generated on 2021-03-20 18:02:10.

  • 1
    Are you certain you don't have any mod loaders, e.g on different versions of minecraft?
    – Corsaka
    Mar 31, 2021 at 8:23

3 Answers 3


I mean you can delete it but it'll just regenerate. It's a folder created by mixins, hence the name.

  • 2
    why is it there though?
    – Penguin
    Mar 30, 2021 at 19:39
  • 2
    @Penguin it was created by mixin because he uses mixin mods like Fabric Mod Loader Mar 30, 2021 at 21:48
  • 1
    the user didnt specify that information in the question. @RayWu
    – Cole Busby
    Mar 30, 2021 at 22:49
  • @ColeBusby This is basically the only reason, it's definitely a mod. Mar 31, 2021 at 14:24

This folder contains various caching and debugging information utilized by the Mixin library, which is used by mods that need to patch the code of the game in some way (such mods were called coremods in the past).

Fabric, for example, completely revolves around Mixin, but Forge mods often use it as well and starting somewhere from 1.15 I think Forge even ships it with it, just as Fabric - that's why you are getting an empty report, even if you have no mods other than Optifine or something.

It provides a much easier way of dealing with Java bytecode and stuff, helping modders do stuff much faster and make such mods much more compatible with each other.

This folder does no harm, usually shouldn't take up any noticeable space either, and as others have said, will be just regenerated by Mixin if not present.



Mixin is a library used by other mods and/or resource packs to provide additional functionality. It's leveraged by the mods in order to hotpatch minecraft. If you View hidden files (windows) you may see more information for you to make an intelligent, informed decision as to the future of this directory, however do be aware that since this is a directory that is leveraged by mods, plugins or packs it can regenerate.

what does it hurt to keep it though?

nothing. not. a. thing.

So I can delete it?

You have to answer this yourself. You may break mods, plugins or resourcepacks. however, if you find this in a vanilla install of minecraft java edition. It's likely in use by microsoft to hotpatch some things for performance.

Google is your friend, when it comes to the content of this directory. I've purged mine with no issues, but it did regenerate when i launched my forge-powered mod.

  • When would this be in a normal minecraft installation? I cant find anything that supports that and I dont have it myself either
    – Penguin
    Mar 30, 2021 at 22:23
  • @Penguin I personally do not work for mojang but if you want hypotheticals I'll open the door here and prefer to close it after: 1. Microsoft wants to shim in some C# classes and leverage a C# to java cross-compiler such as Xamarin in order to accomplish the task OR could use Mixin for some non-native-to-java-feature that is native to bedrock. 2. Performance enhancement. 3. myriad of java cross-compilation/asm tweaks in java bytecode. But to answer the top-level question: under what circumstances should I expect to see this in a vanilla install? If MSFT is doing right, you shouldn't.
    – Cole Busby
    Mar 30, 2021 at 22:26
  • 1
    Can I still get this when I download a mod from twitch? hell yes you can. Can I still get this when i use a forge installer? you betcha. Can I have this in bedrock? I don't own bedrock. It's 2021. I'm not going to cover every possible nook and cranny in my post. Instead, I'll give you generics, avenues to research and the locations on which you can further find information.
    – Cole Busby
    Mar 30, 2021 at 22:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .