Free Claude context tools
Plan context, test compaction, and price prompt caching before you ship.
These tools run entirely in your browser. They use dated source-backed model windows and pricing facts, but they do not send prompts, documents, or assumptions anywhere.
Free Browser Tool
Context Planner
Allocate a Claude context window across instructions, tools, history, retrieval, working notes, and output reserve using current published model window sizes.
- Model-aware context budget math
- Live segment visualization
- Output reserve warnings
Open tool
Free Browser Tool
Compaction Simulator
See how long Claude conversations can be summarized: what survives compaction, what becomes a short note, and what should be re-fetched or discarded.
- Adjustable context trigger threshold
- Editable turn token weights
- Survives versus lost context report
Open tool
Free Browser Tool
Caching Calculator
Estimate daily savings from Claude prompt caching using current dated cache write and cache read prices from the Claude Platform pricing docs.
- Current model cache pricing
- 5-minute versus 1-hour TTL comparison
- Hit-rate and rewrite-frequency controls
Open tool
Related reading
Use the tools with the field guide.
Context Window
A sourced guide to Claude context windows: what counts, why larger context is not automatically better, and how to measure tokens before you send.
Compaction
How to choose between Claude compaction, tool-result clearing, and memory when long conversations or agents exceed useful context.
Prompt Caching
When Claude prompt caching helps, what it caches, what TTLs mean, and why caching is not a substitute for context selection.