Context Window Guide

What is a Context Window?

A context window is the maximum amount of text an AI model can process at once. Think of it as the model's "working memory" - it determines how much of your conversation and code the model can consider when generating responses.

Context Window Sizes

Quick Reference

Model Context Windows

*Effective window is where model maintains high quality

Managing Context Efficiently

What Counts Toward Context

1. Your current conversation - All messages in the chat
2. File contents - Any files you've shared or Cline has read
3. Tool outputs - Results from executed commands
4. System prompts - Cline's instructions (minimal impact)

Optimization Strategies

1. Start Fresh for New Features

/new - Creates a new task with clean context

Benefits:

• Maximum context available
• No irrelevant history
• Better model focus

2. Use @ Mentions Strategically

Instead of including entire files:

• @filename.ts - Include only when needed
• Use search instead of reading large files
• Reference specific functions rather than whole files

3. Enable Auto-compact

Cline can automatically summarize long conversations:

• Settings → Features → Auto-compact
• Preserves important context
• Reduces token usage

Context Window Warnings

Signs You're Hitting Limits

Best Practices by Project Size

Small Projects (< 50 files)

• Any model works well
• Include relevant files freely
• No special optimization needed

Medium Projects (50-500 files)

• Use 128K+ context models
• Include only working set of files
• Clear context between features

Large Projects (500+ files)

• Use 200K+ context models
• Focus on specific modules
• Use search instead of reading many files
• Break work into smaller tasks

Advanced Context Management

Plan/Act Mode Optimization

Leverage Plan/Act mode for better context usage:

• Plan Mode: Use smaller context for discussion
• Act Mode: Include necessary files for implementation

Configuration:

Plan Mode: DeepSeek V3 (128K) - Lower cost planning
Act Mode: Claude Sonnet (1M) - Maximum context for coding

Context Pruning Strategies

1. Temporal Pruning: Remove old conversation parts
2. Semantic Pruning: Keep only relevant code sections
3. Hierarchical Pruning: Maintain high-level structure, prune details

Token Counting Tips

Rough Estimates

• 1 token ≈ 0.75 words
• 1 token ≈ 4 characters
• 100 lines of code ≈ 500-1000 tokens

File Size Guidelines

Context Window FAQ

Q: Why do responses get worse with very long conversations?

A: Models can lose focus with too much context. The "effective window" is typically 50-70% of the advertised limit.

Q: Should I use the largest context window available?

A: Not always. Larger contexts increase cost and can reduce response quality. Match the context to your task size.

Q: How can I tell how much context I'm using?

A: Cline shows token usage in the interface. Watch for the context meter approaching limits.

Q: What happens when I exceed the context limit?

A: Cline will either:

• Automatically compact the conversation (if enabled)
• Show an error and suggest starting a new task
• Truncate older messages (with warning)

Recommendations by Use Case