Updated March 26, 2026· Based on independent benchmark data
GPT-5.3 Codex (xhigh) and Claude Opus 4.6 (Adaptive Reasoning, Max Effort) are virtually tied on intelligence (54.0 vs 53.0). GPT-5.3 Codex (xhigh) is 2.9x cheaper at $1.75/1M tokens vs $5.00/1M. For speed, GPT-5.3 Codex (xhigh) wins at 72 tok/s vs 51 tok/s.
| Metric | GPT-5.3 Codex (xhigh) | Claude Opus 4.6 (Adaptive Reasoning, Max Effort) |
|---|---|---|
| Intelligence Score | 54.0 | 53.0 |
| Coding Score | 53.1 | 48.1 |
| Math Score | N/A | N/A |
| Speed (tok/s) | 72 tok/s | 51 tok/s |
| Latency (TTFT) | 83.91s | 12.63s |
| Input Price / 1M tokens | $1.75 | $5.00 |
| Output Price / 1M tokens | $14 | $25 |
| Context Window |
GPT-5.3 Codex (xhigh) and Claude Opus 4.6 (Adaptive Reasoning, Max Effort) perform similarly on overall intelligence, scoring 54.0 and 53.0 respectively. For coding tasks, GPT-5.3 Codex (xhigh) has the edge with a coding score of 53.1 vs 48.1.
GPT-5.3 Codex (xhigh) generates output significantly faster at 72 tok/s compared to Claude Opus 4.6 (Adaptive Reasoning, Max Effort)'s 51 tok/s, making it 1.4x faster for streaming responses. Time to first token is 12.63s for Claude Opus 4.6 (Adaptive Reasoning, Max Effort) vs 83.91s for GPT-5.3 Codex (xhigh), which affects perceived responsiveness in interactive applications.
GPT-5.3 Codex (xhigh) is more affordable at $1.75/1M input tokens ($14/1M output), while Claude Opus 4.6 (Adaptive Reasoning, Max Effort) costs $5.00/1M input ($25/1M output). That makes Claude Opus 4.6 (Adaptive Reasoning, Max Effort) 2.9x more expensive per token, which can add up significantly at scale. For a typical workload of 100 requests per day at 2,000 tokens each, GPT-5.3 Codex (xhigh) would cost approximately $10.50/month vs $30.00/month for Claude Opus 4.6 (Adaptive Reasoning, Max Effort) in input costs alone.
Choose GPT-5.3 Codex (xhigh) when you need stronger coding performance (53.1), faster output (72 tok/s), lower cost.
GPT-5.3 Codex (xhigh) scores higher on coding benchmarks (53.1 vs 48.1), making it the better choice for programming tasks.
GPT-5.3 Codex (xhigh) is cheaper at $1.75/1M input tokens vs $5.00/1M for Claude Opus 4.6 (Adaptive Reasoning, Max Effort).
GPT-5.3 Codex (xhigh) is faster, producing output at 72 tok/s compared to Claude Opus 4.6 (Adaptive Reasoning, Max Effort)'s 51 tok/s.
No, GPT-5.3 Codex (xhigh) does not support image input. Neither model supports image input.
Data last synced: March 26, 2026
| N/A |
| N/A |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Text |
| Output Modalities | Text | Text |
| Free Tier | No | No |
Both models perform similarly on intelligence benchmarks. Choose based on specific needs: pricing, speed, context window, or provider ecosystem.