The Claude Desktop app for macOS looks like a chat client, but underneath it is an Electron app with its own browser engine — and it accumulates session data, cached attachments and logs the same way a browser does. After a few months of daily use, it is common to find it holding several gigabytes.

Step 1: find out how much it actually uses

Open Terminal and run:

du -sh ~/Library/Application\ Support/Claude \
         ~/Library/Caches/Claude* \
         ~/Library/Logs/Claude 2>/dev/null

The three lines that matter:

Path	What it holds	Safe to delete?
~/Library/Application Support/Claude	Sessions, IndexedDB, MCP server data, settings	No — not wholesale. Delete old conversations from inside the app instead
~/Library/Caches/Claude (and com.anthropic.* variants)	HTTP cache, rendered assets, downloaded updates	Yes — quit the app first, it rebuilds them
~/Library/Logs/Claude	Diagnostic logs (grow forever with MCP servers installed)	Yes

Step 2: the in-app cleanup that actually frees space

Attachments are the hidden hog: every PDF or image you dropped into a conversation stays cached so the conversation can re-render it. Open old chats with big attachments and delete the conversations you no longer need (chat menu → Delete). This removes the stored copies from Application Support on the next app restart.

Step 3: quit → clear caches → relaunch

osascript -e 'quit app "Claude"'
rm -rf ~/Library/Caches/Claude ~/Library/Caches/com.anthropic.claudefordesktop
rm -rf ~/Library/Logs/Claude/*.log
open -a Claude

Expect the app to feel slightly slower on first launch (cache rebuild) and then behave normally. In our test this freed 2.3 GB on a machine where the app was installed for eight months.

Step 4: if you use MCP servers, audit them

Each MCP server keeps its own state — filesystem servers index directories, database connectors cache results. If a folder you connected to is huge, Claude's indexing artifacts will be too. Remove unused connectors from Settings → Extensions, then clear the caches again.

When the disk is still full after this

Claude Desktop is rarely alone. Our Claude Code disk guide covers the terminal app's multi-GB transcript folder, and the general Mac disk-full walkthrough covers everything else. For a one-click picture of what is eating the drive, a visualizer like DaisyDisk (macOS) or a maintenance suite such as MacCleaner PRO maps the remaining hot spots in minutes.