Managing Context
Claude Code's output quality degrades as the context window fills up. Understanding and managing context usage is critical for long sessions.
The compaction threshold
When context usage grows large, Claude Code's responses become less focused and more prone to errors. Run /compact proactively when you reach roughly 50% context usage. Do not wait for the automatic compaction, which triggers much later and may already be past the point of optimal performance.
Practical tips
- Check context usage with the status line or
/costcommand to see how much of the window you have used - Start new sessions for unrelated tasks instead of reusing a long-running session
- Size subtasks so each one can complete well within 50% of available context
- Use subagents for noisy tasks (large searches, exploring unfamiliar code) so the main context stays clean
Checkpointing
Claude Code automatically tracks file edits with git-based checkpoints. If something goes wrong, you can rewind to a previous state:
- Press
Esctwice to undo the last set of changes - Use
/rewindto go back to a specific checkpoint
This makes it safe to let Claude Code try ambitious changes: you can always roll back.