AI & Prompt Tools · Free tool
AI Context Window Planner
Plan your prompt budget across system + docs + history + output + buffer. See which AI models (Claude, GPT, Gemini, DeepSeek, Kimi) fit your needs.
Updated June 2026
Total budgeted
92k tokens
| Model | Context | Status | Headroom |
|---|---|---|---|
| Claude Sonnet 4.6 | 1,000k | fits | 908k |
| Claude Opus 4.7 | 1,000k | fits | 908k |
| Claude Haiku 4.5 | 200k | fits | 108k |
| GPT-5 | 400k | fits | 308k |
| GPT-5 mini | 400k | fits | 308k |
| Gemini 3 Pro | 2,000k | fits | 1,908k |
| Gemini 2.5 Pro | 2,000k | fits | 1,908k |
| Gemini 2.5 Flash | 1,000k | fits | 908k |
| DeepSeek V3.2 | 128k | fits | 36k |
| Kimi K2 | 1,000k | fits | 908k |
Why the buffer matters: models degrade in quality near max context. Most pros operate at 50-70% of the rated context window for production reliability. If you’re budgeting 90%+ of the context, downsize the document or upgrade the model.
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What it does
Plan your prompt token budget across system prompt, documents, chat history, output, and safety buffer. See which AI models (Claude Sonnet 4.6 / Opus 4.7 / Haiku 4.5 / GPT-5 / Gemini 3 Pro / DeepSeek V3.2 / Kimi K2) fit with how much headroom. Models degrade near max context — operate at 50-70% of the rated window for production reliability.
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Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.
<iframe src="https://freetoolarena.com/embed/ai-context-window-planner" width="100%" height="720" frameborder="0" loading="lazy" title="AI Context Window Planner" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>How to use it
- Enter token budgets per category.
- Read which models fit + headroom for each.
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