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Prompt Token Budget Planner

Split a model's context window across system prompt, tools, memory, retrieved documents and history, with a warning when allocation passes 80%.

Prompt Token Budget Planner

Quick presets

Budget sections

tokens
Paste text to auto-count tokens

Estimated at ~3.5 chars/token for Claude

tokens
Paste text to auto-count tokens

Estimated at ~3.5 chars/token for Claude

tokens
Paste text to auto-count tokens

Estimated at ~3.5 chars/token for Claude

tokens
Paste text to auto-count tokens

Estimated at ~3.5 chars/token for Claude

tokens
Paste text to auto-count tokens

Estimated at ~3.5 chars/token for Claude

Budget allocation

01,000,000 tokens

1.1% of context allocated, 989,000 tokens left

Total allocated
11,000
1.1% of context
Remaining
989,000
98.9% available
Est. turns
~1978
at 500 tokens/turn
Status
Healthy
Good balance

About token budget planning

This tool helps you plan how to allocate your model's context window across different sections of your AI system prompt. Use it to ensure you leave enough room for conversation history while including necessary context.

Token estimates use ~3.5 chars/token for Claude. Actual counts may vary. For precise counting, use the Token Counter tool.

Updated . Provided as is. Check the output before you rely on it in production.

How to use Prompt Token Budget Planner

  1. 1

    Pick a model or preset

    Choose the target model's context window, or start from a preset such as Minimal Agent, Heavy Context Agent or RAG System.

  2. 2

    Add budget sections

    Add a section for each part of the prompt, such as system prompt, tools, memory, retrieved documents and conversation history. Enter a token count or paste text to estimate it.

  3. 3

    Read the allocation

    See total allocated and remaining tokens, estimated turns left at 500 tokens per turn, and a warning as you approach the limit.

  4. 4

    Download the plan

    Download the budget to share with your team or keep it next to the prompt it describes.

Questions and answers

What is Prompt Token Budget Planner?
A token budget is how a model's context window is divided between instructions, tool definitions, memory, retrieved documents and conversation history. Here you enter or estimate tokens per section against a chosen model's context window, see the share each takes, and get a warning above 80%.
Does Prompt Token Budget Planner store or send my data?
No. All processing happens entirely in your browser. Your prompt content never leaves your device — nothing is sent to any server.
Why do I need to plan my token budget?
AI models have fixed context windows. If your system prompt uses too many tokens, there is less room for user messages and responses. Budget planning helps you optimize prompt length for better results and lower costs.
For AI agents: how to call this tool

Machine-readable contract, endpoints and examples. Humans can ignore this section.

Best Path For Builders

Browser workflow

Runs instantly in the browser with private local processing and copy/export-ready output.

Browser Workflow

This tool is optimized for instant in-browser execution with local data handling. Run it here and copy/export the output directly.

/token-budget-planner/

For automation planning, fetch the canonical contract at /api/tool/token-budget-planner.json.