Context Window Visualization - Claude Code

Context window visualization turns the abstract "how full is context?" question into a timeline you can actually read.

What it does

The view shows each turn, tool call, and file read as a block on a timeline, sized by tokens. You can see which reads dominated, where compaction kicked in, and what was dropped. It's the first place to look when Claude starts to feel forgetful or when you want to tune your prompts for efficiency.

When to use it

• Debugging "Claude forgot X" moments in long sessions.
• Tuning prompts to avoid oversized file reads.
• Planning compaction points for marathon sessions.
• Teaching yourself how context economy actually works.

Gotchas

• The view samples recent turns - very old history may not render in detail.
• Token counts are estimates. Exact billing still comes from the API.
• Large images or PDFs show up as big blocks. That's real, not a visualization bug.

Official docs: https://code.claude.com/docs/en/context-window.md