Aider vs Windsurf (now Devin Desktop)

Pick two tools from the same category to compare side-by-side.

	Aider OSS AI pair programmer for the terminal; multi-model, git-native.	Windsurf (now Devin Desktop) Agentic AI IDE acquired by Cognition in 2025 and rebranded Devin Desktop in June 2026.
Category	harness	harness
Vendor type	open source	commercial
Pricing	free	freemium
Strengths	+ Fully open source + Multi-model (Anthropic, OpenAI, OpenRouter, local) + Git-native commit-per-change workflow	+ Full IDE experience with agent, tab completion, and multi-file edits integrated + Backed by Cognition's proprietary SWE coding models plus frontier model access + Free tier available; settings and extensions carried over from Windsurf
Tradeoffs	− Less polished than IDE-based harnesses − No managed plugin ecosystem	− Closed source and tied to Cognition's platform and credit quotas − 2025-2026 ownership changes and the Devin rebrand forced workflow migrations (e.g. Cascade deprecation)
Used in stacks	1	0