Aider vs Windsurf: Side-by-Side Comparison 2026

Aider vs Windsurf comparison 2026. Side-by-side features, pricing & capabilities.

Aider is a CLI-based coding agent from Paul Gauthier (Open Source) — ai pair programming in your terminal. Windsurf is an AI IDE from Cognition — the agentic ai ide.

Aider

Open-source CLI tool for AI pair programming. Works with OpenAI, Claude, and other models to edit code in your local git repo.

  • ✓ Git-aware editing
  • ✓ Multi-file editing
  • ✓ Model agnostic
  • ✓ Voice coding
  • ✓ Image support

Free · 1 plan

Windsurf

AI-first IDE with Cascade — an agentic assistant that understands your codebase and makes multi-file changes. Now owned by Cognition (makers of Devin). Also available as Windsurf Plugin for VS Code and JetBrains.

  • ✓ Cascade agentic AI
  • ✓ Code completions
  • ✓ Multi-file editing
  • ✓ Terminal integration
  • ✓ Codebase search

Free / $20/mo · 5 plans

Feature Aider Windsurf
Category CLIAI IDE
Starting Price Free Free
Model Family Multi-model (any)Multi-model
Documentation — ✓
Voice Input ✓ —
Git Integration — ✓
Open Source Yes (Apache 2.0)No

Pricing verified Mar 20, 2026. Aider pricing | Windsurf pricing

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Key Differences

  • Category: Aider is a CLI-based coding agent; Windsurf is an AI IDE.
  • Starting price: Aider starts at free / BYOK; Windsurf starts at $20/mo.
  • Model family: Aider uses Multi-model (any); Windsurf uses Multi-model.
  • Open source: Aider: Yes (Apache 2.0). Windsurf: No.
  • Provider: Aider is built by Paul Gauthier (Open Source); Windsurf is built by Cognition.
  • Capabilities: Aider has voice input.

Which Should You Choose?

Choose Aider if you want a fully open-source tool with transparent development. Choose Windsurf if you want an agentic IDE with autonomous multi-step changes. Read our full reviews to see which fits your workflow.

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