• Windows
  • System

AppData is three folders, and only one of them is disposable

Roaming, Local and LocalLow hold different things with different rules. What each is for, and which parts are safe to clear.

6 min read

AppData is where nearly everything an application saves on Windows ends up, and it is hidden by default. On a machine used for a few years it is frequently the largest folder in the user profile, and the three folders inside it follow different rules.

The three folders

FolderWhat it holdsSafe to clear
RoamingSettings meant to follow you between PCs on a domainNo, this is configuration
LocalCaches and data tied to this machineSelectively, per app
LocalLowData from low integrity processes, mostly browsers and pluginsUsually yes, and it is small

The distinction that matters

Roaming is designed to be copied to another machine when you sign in there. That tells you what is in it: preferences, profiles, signing keys, anything the application considers part of who you are. Local is explicitly the opposite, which is why caches, downloaded components and machine specific state live there.

So the rule of thumb is: clear inside Local, leave Roaming alone, and treat LocalLow as noise. It is a rule of thumb rather than a law, because plenty of applications ignore the convention and put real data in Local.

Finding what is big

Get-ChildItem $env:LOCALAPPDATA -Directory -Force |
  ForEach-Object {
    $s = (Get-ChildItem $_.FullName -Recurse -Force -File -ErrorAction SilentlyContinue |
          Measure-Object Length -Sum).Sum
    [PSCustomObject]@{ MB = [math]::Round($s/1MB); Name = $_.Name }
  } | Sort-Object MB -Descending | Select-Object -First 20

Read the result for names you cannot place. A large folder belonging to software you still use is that software working; a large folder belonging to something you removed two years ago is dead weight, and that is a separate problem.

The usual occupants

  • Browsers. Profiles, caches and service worker storage, routinely several gigabytes each.
  • Chat and meeting apps. Every one of them is a browser in a wrapper and stores like one.
  • Editors and IDEs. Extensions, indexes and per project state.
  • Package manager caches. npm, pip, NuGet and the rest, all under Local.

What not to do

Do not empty AppData. It is not a cache folder, it is where your applications keep their settings and in many cases your data: note apps, password managers and mail clients all store real content there. Clearing it wholesale is the Windows equivalent of deleting a Mac's Library folder, and it has the same outcome.

Common questions

What is the difference between Roaming and Local in AppData?

Roaming is meant to follow you to other PCs on a domain, so it holds settings and profile data. Local is specific to the machine, which is where caches and downloaded components live. Clear inside Local, leave Roaming alone.

Is it safe to delete AppData?

No, not as a whole. It holds application settings and, for many programs, your actual data. Clearing specific cache folders inside AppData\Local is the safe version of the idea.

Why is AppData so large?

Browsers, chat apps, editors and package manager caches all live there, and none of them clear up after themselves. On a personal machine of a few years, tens of gigabytes is ordinary.

What is LocalLow for?

Data written by low integrity processes, mainly browsers and their plugins. It is usually small and generally safe to clear.

Read next