Aider vs Claude Cowork

AI Agent Reliability Comparison

According to StupidLLM's incident database of 64 documented AI agent failures, Aider has 1 incidents (avg severity 6.3/10) while Claude Cowork has 1 (avg severity 10.0/10). Here's how these two AI coding agents compare on reliability, failure modes, and real-world risk.

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

Claude Cowork

1
Incidents
10.0
Avg Severity
1
Critical
0
High

Top Failure Modes

Destructive Action 1

Worst Incident

STUPID-2026-0043 10/10
Claude Cowork deleted 15 years of family photos when asked only to tidy temporary Office files

Comparison Summary

Metric Aider Claude Cowork
Total Incidents 1 1
Avg Severity 6.3/10 10.0/10
Critical Incidents 0 1
Top Failure Mode Wrong File Destructive Action

Frequently Asked Questions

Is Aider or Claude Cowork more reliable?

Based on StupidLLM's incident database, Aider has 1 documented failures (avg severity 6.3/10) while Claude Cowork has 1 (avg severity 10.0/10). Aider shows better reliability based on average severity scores.

What are the main differences between Aider and Claude Cowork failures?

Aider's most common failure mode is wrong file, while Claude Cowork most commonly fails via destructive action. Aider has 0 critical incidents vs Claude Cowork's 1.

Which has more critical-severity failures?

Claude Cowork has more critical failures (1 vs 0), indicating a higher likelihood of severe, production-impacting incidents.

What is the most dangerous failure mode for Aider?

Aider's most frequent failure mode is wrong file — its worst documented incident (STUPID-2026-0005) was rated 6.3/10 severity. Understanding these failure patterns helps teams decide whether Aider is safe for their specific use case.

What is the most dangerous failure mode for Claude Cowork?

Claude Cowork's most frequent failure mode is destructive action — its worst documented incident (STUPID-2026-0043) was rated 10/10 severity. Understanding these failure patterns helps teams decide whether Claude Cowork is safe for their specific use case.

Should I use Aider or Claude Cowork for production code?

Based on StupidLLM's reliability data, Aider has a lower average failure severity (6.3/10 vs 10.0/10), making it the statistically safer choice for production environments. However, both agents have documented critical incidents — no AI coding agent is risk-free.

How many verified incidents does each agent have?

Aider has 1 verified incidents out of 1 total, while Claude Cowork has 1 verified out of 1. Verified incidents are confirmed against source evidence (GitHub PRs, bug reports, news articles), making them the most reliable data points in StupidLLM's database.

How does Aider compare to other AI agents?

StupidLLM tracks 27 AI coding agents. Aider has 1 documented failures — placing it in the mid-range for reliability. See the full comparison matrix for context against all tracked agents.

How does Claude Cowork compare to other AI agents?

StupidLLM tracks 27 AI coding agents. Claude Cowork has 1 documented failures — placing it among the higher-risk agents in the database. See the full comparison matrix for context against all tracked agents.