Is Codex or GPT-5.6-Sol more reliable?

Based on StupidLLM's incident database, Codex has 3 documented failures (avg severity 5.8/10) while GPT-5.6-Sol has 3 (avg severity 9.0/10). Codex shows better reliability.

What are the main differences between Codex and GPT-5.6-Sol failures?

Codex's most common failure mode is Destructive Action, while GPT-5.6-Sol most commonly fails via Destructive Action. Codex has 0 critical incidents vs GPT-5.6-Sol's 2.

Which has more critical-severity failures?

GPT-5.6-Sol has more critical failures (2 vs 0), indicating a higher likelihood of severe, production-impacting incidents.

Should I use Codex or GPT-5.6-Sol for production code?

Codex has a lower average failure severity (5.8/10 vs 9.0/10), 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?

Codex has 2 verified incidents out of 3 total, while GPT-5.6-Sol has 2 verified out of 3. Verified incidents are confirmed against source evidence.

Head to head

Codex vs GPT-5.6-Sol

Comparing 3 documented Codex incidents against 3 for GPT-5.6-Sol.

Full Codexreport →Full GPT-5.6-Solreport →

Verdict

Codex has the lower average failure severity (5.8/10 vs 9.0/10), making it the statistically safer choice of the two — though both agents have documented critical incidents.