Aider vs Windsurf

AI Agent Reliability Comparison

Aider

1
Incidents
6.3
Avg Severity
0
Critical
0
High

Top Failure Modes

Wrong File 1

Worst Incident

STUPID-2026-0005 6.3/10
Aider modified wrong file — edited production config instead of dev config

Windsurf

1
Incidents
7.5
Avg Severity
0
Critical
1
High

Top Failure Modes

Ignored Instructions 1

Worst Incident

STUPID-2026-0007 7.5/10
Windsurf ignored .gitignore and committed node_modules and .env

Comparison Summary

Metric Aider Windsurf
Total Incidents 1 1
Avg Severity 6.3/10 7.5/10
Critical Incidents 0 0
Top Failure Mode Wrong File Ignored Instructions

Frequently Asked Questions

Is Aider or Windsurf more reliable?

Based on StupidLLM data, Aider has 1 documented failures (avg severity 6.3/10) while Windsurf has 1 (avg severity 7.5/10). Aider shows better reliability based on average severity scores.

What are the main differences between Aider and Windsurf failures?

Aider's most common failure mode is wrong file, while Windsurf most commonly fails via ignored instructions. Aider has 0 critical incidents vs Windsurf's 0.