Cline vs Windsurf
AI Agent Reliability Comparison
According to StupidLLM's incident database of 64 documented AI agent failures, Cline has 1 incidents (avg severity 10.0/10) while Windsurf has 1 (avg severity 7.5/10). Here's how these two AI coding agents compare on reliability, failure modes, and real-world risk.
Cline
Top Failure Modes
Worst Incident
STUPID-2026-0030 10/10Windsurf
Top Failure Modes
Worst Incident
STUPID-2026-0007 7.5/10Comparison Summary
| Metric | Cline | Windsurf |
|---|---|---|
| Total Incidents | 1 | 1 |
| Avg Severity | 10.0/10 | 7.5/10 |
| Critical Incidents | 1 | 0 |
| Top Failure Mode | Security Vulnerability | Ignored Instructions |
Frequently Asked Questions
Is Cline or Windsurf more reliable?
Based on StupidLLM's incident database, Cline has 1 documented failures (avg severity 10.0/10) while Windsurf has 1 (avg severity 7.5/10). Windsurf shows better reliability based on average severity scores.
What are the main differences between Cline and Windsurf failures?
Cline's most common failure mode is security vulnerability, while Windsurf most commonly fails via ignored instructions. Cline has 1 critical incidents vs Windsurf's 0.
Which has more critical-severity failures?
Cline has more critical failures (1 vs 0), indicating a higher likelihood of severe, production-impacting incidents.
What is the most dangerous failure mode for Cline?
Cline's most frequent failure mode is security vulnerability — its worst documented incident (STUPID-2026-0030) was rated 10/10 severity. Understanding these failure patterns helps teams decide whether Cline is safe for their specific use case.
What is the most dangerous failure mode for Windsurf?
Windsurf's most frequent failure mode is ignored instructions — its worst documented incident (STUPID-2026-0007) was rated 7.5/10 severity. Understanding these failure patterns helps teams decide whether Windsurf is safe for their specific use case.
Should I use Cline or Windsurf for production code?
Based on StupidLLM's reliability data, Windsurf has a lower average failure severity (7.5/10 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?
Cline has 1 verified incidents out of 1 total, while Windsurf 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 Cline compare to other AI agents?
StupidLLM tracks 27 AI coding agents. Cline 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.
How does Windsurf compare to other AI agents?
StupidLLM tracks 27 AI coding agents. Windsurf 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.