GPT-5.4 (xhigh) vs GPT-5.3 Codex (xhigh): Which Large Language Models is Best?

Verdict: GPT-5.4 (xhigh) wins by 3 points.

GPT-5.4 (xhigh) takes the lead in this comparison, scoring 57 points to GPT-5.3 Codex (xhigh)'s 54. This 3-point gap suggests that GPT-5.4 (xhigh) outperforms its competitor in general intelligence.

For users focused on reasoning, coding capabilities, GPT-5.4 (xhigh) from OpenAI currently represents the state-of-the-art. Its higher Elo score indicates greater consistency across our benchmark set.

However, GPT-5.3 Codex (xhigh) remains a formidable contender. Ranked #3, it is a top-tier choice. Depending on your specific needs—such as licensing (Proprietary) or ecosystem integration—GPT-5.3 Codex (xhigh) may still be the right tool for your pipeline.

Comparison Data

Feature	GPT-5.4 (xhigh)	GPT-5.3 Codex (xhigh)
Rank	#2	#3
Score	57	54
Developer	OpenAI	OpenAI
License	Proprietary	Proprietary

Conclusion

Both models are excellent choices within the Large Language Models landscape. We recommend checking the full leaderboard for the most up-to-date rankings as new models are released frequently.