Steam Is Using 100 GB on My Mac: How to Find and Free the Space (2026)

If you have opened macOS Settings, clicked Storage, and found Steam quietly consuming 80–120 GB you cannot fully account for, you are not imagining it. Steam on macOS scatters data across several locations — and the default in-client storage report only shows you part of the picture. This guide walks through every folder Steam touches, which ones are safe to delete, and how to audit the situation so you cut the right fat when steam is using too much storage on your Mac.

Why Steam Uses So Much Space on macOS

Steam's footprint is larger than "game files" because it maintains several additional categories of data side by side:

• Game installs — the actual game content you play.
• Download staging (depots) — Steam downloads updates as encrypted depot chunks before applying them. An interrupted update can leave these chunks on disk indefinitely.
• Shader pre-compilation cache — macOS Metal shaders are compiled per-GPU per-driver version. Steam stores these inside each game's folder and they can grow large over time.
• Workshop / user content — mods, maps, and assets from the Steam Workshop accumulate here.
• Steam client data — browser cache, download history, and the Steam client app itself.
• Screenshots and cloud saves — locally cached copies of Steam Cloud data.

Where Steam Stores Data on macOS

Steam spreads its data across two root areas. Knowing the exact paths is prerequisite to cleaning anything safely.

The Steam Library Folder

By default this is:

~/Library/Application Support/Steam/steamapps/

If you have added extra library locations via Steam → Settings → Storage, those paths are wherever you chose (often an external drive or a second internal volume). Each library folder has the same internal structure:

• common/ — installed games, one subfolder per game.
• downloading/ — in-progress downloads. Safe to delete only if no download is active.
• temp/ — staging area for updates. Usually cleaned by Steam on next launch, but not always.
• workshop/content/ — Workshop items, keyed by AppID.
• shadercache/ — per-game compiled Metal shaders, keyed by AppID.
• screenshots/ — your in-game screenshots.

The Steam Client Application Data

~/Library/Application Support/Steam/

This contains the client's own cache, your login tokens, cached artwork, and the browser data for Steam's built-in web view. It is separate from your game library.

Step 1: Get a Size Breakdown Before You Delete Anything

The single biggest mistake people make is deleting blindly. Run this command in Terminal to see exactly how large each category is inside your default library:

du -sh ~/Library/Application\ Support/Steam/steamapps/*/  2>/dev/null | sort -rh | head -30

For a full recursive breakdown including the shadercache and workshop folders:

du -sh ~/Library/Application\ Support/Steam/steamapps/common/* \
       ~/Library/Application\ Support/Steam/steamapps/shadercache/* \
       ~/Library/Application\ Support/Steam/steamapps/workshop/content/* \
  2>/dev/null | sort -rh | head -40

If you have multiple library locations, repeat the command for each path. The output will often surface a single game — or a shader cache for a game you deleted months ago — as the true culprit.

Alternatively, Crumb's whole-Mac visual audit renders your entire disk as a treemap, so Steam's folders appear as proportional blocks you can click into. It is a faster way to spot an outsized shadercache/ or workshop/ directory without running multiple Terminal commands.

Step 2: Uninstall Games You No Longer Play (The Right Way)

Removing a game through Steam is always the correct first step — it also removes the AppManifest_XXXXX.acf file that tracks the install, preventing orphan entries.

1. Open Steam and go to your Library.
2. Right-click the game → Manage → Uninstall.
3. Confirm. Steam removes the common/GameName/ folder.
4. Repeat for every game you have not launched in the past year.

What Steam does NOT remove automatically:

• The shader cache in shadercache/APPID/
• Workshop content in workshop/content/APPID/
• Screenshots in screenshots/APPID/

You must delete these manually if you want to fully reclaim the space.

Step 3: Clear Shader Caches for Uninstalled Games

Shader caches are safe to delete. Steam (or the game on next launch) will rebuild them. The risk is that the next time you launch a game, you will experience a compilation stall for a few minutes — not data loss.

# List all shader cache folders and their sizes
du -sh ~/Library/Application\ Support/Steam/steamapps/shadercache/*

# Delete the shader cache for a specific AppID (replace 12345 with the real ID)
rm -rf ~/Library/Application\ Support/Steam/steamapps/shadercache/12345

To find an AppID for a game, check the URL on that game's Steam store page — it is the number after /app/.

If you want to wipe all shader caches at once (safe, but every game will recompile on next launch):

rm -rf ~/Library/Application\ Support/Steam/steamapps/shadercache/

Step 4: Remove Depot and Temp Leftovers

The downloading/ and temp/ folders inside your library should be empty when no downloads are running. If they are not, it means a previous update was interrupted.

1. Fully quit Steam (Steam → Quit Steam, not just closing the window).
2. Verify Steam is not running: pgrep -x steam should return nothing.
3. Check the sizes:

du -sh ~/Library/Application\ Support/Steam/steamapps/downloading/
du -sh ~/Library/Application\ Support/Steam/steamapps/temp/

4. If either folder has content and Steam is not running, it is safe to delete:

rm -rf ~/Library/Application\ Support/Steam/steamapps/downloading/*
rm -rf ~/Library/Application\ Support/Steam/steamapps/temp/*

Do not delete these folders while Steam is running or a download is paused — Steam may re-download the entire game if the manifest is corrupted mid-transfer.

Step 5: Trim the Steam Client Cache

Steam's built-in browser and image cache can reach several gigabytes on a long-lived install. This is separate from game data.

du -sh ~/Library/Application\ Support/Steam/htmlcache/
du -sh ~/Library/Application\ Support/Steam/appcache/

You can clear these while Steam is closed. Steam will rebuild them (it will feel like a fresh install of the client briefly):

rm -rf ~/Library/Application\ Support/Steam/htmlcache/
rm -rf ~/Library/Application\ Support/Steam/appcache/

What Is Safe vs. What Is Not

Move Your Library to Reclaim System Drive Space

If your Mac has a secondary volume or an external SSD, moving Steam's library there keeps your system drive clear without deleting anything:

1. Steam → Settings → Storage → click the + button → select the target drive.
2. Select your current library location → click the three-dot menu → Move Library.
3. Steam copies all content, verifies integrity, then removes the original.

This is non-destructive and is the recommended approach if you play all your installed games regularly.

Keeping Steam Storage Under Control Long-Term

• Enable Steam → Settings → Downloads → Clear download cache periodically — this is the GUI equivalent of removing htmlcache/.
• Review your library once a season and uninstall games with zero recent hours.
• After uninstalling a game through Steam, manually remove its shadercache/APPID/ entry if you will never reinstall it.
• Run a whole-Mac disk audit (via Terminal du or a visual tool like Crumb) quarterly — orphaned game folders from manual moves or failed uninstalls accumulate silently.

Conclusion

Steam's true disk footprint on macOS is almost always larger than the in-client Storage manager suggests, because shader caches, depot leftovers, and Workshop content are accounted for separately. The structured approach — audit first, identify which AppIDs are driving usage, then delete only what you understand — means you will recover significant space without risking save data or having to re-download 60 GB games. Shader caches and temp folders are genuinely throwaway; userdata/ never is. Take fifteen minutes to run the du commands above and the answer to where your space went will almost certainly surprise you.