Updated March 26, 2026· Based on independent benchmark data
GPT-5.3 Codex (xhigh) leads in intelligence with a score of 54.0 vs 48.5. For speed, Grok 4.20 Beta 0309 (Reasoning) wins at 246 tok/s vs 72 tok/s.
| Metric | GPT-5.3 Codex (xhigh) | Grok 4.20 Beta 0309 (Reasoning) |
|---|---|---|
| Intelligence Score | 54.0 | 48.5 |
| Coding Score | 53.1 | 42.2 |
| Math Score | N/A | N/A |
| Speed (tok/s) | 72 tok/s | 246 tok/s |
| Latency (TTFT) | 83.91s | 11.75s |
| Input Price / 1M tokens | $1.75 | $2.00 |
| Output Price / 1M tokens | $14 | $6.00 |
| Context Window | N/A |
GPT-5.3 Codex (xhigh) outperforms Grok 4.20 Beta 0309 (Reasoning) on the intelligence index with a score of 54.0 compared to 48.5. For coding tasks, GPT-5.3 Codex (xhigh) has the edge with a coding score of 53.1 vs 42.2.
Grok 4.20 Beta 0309 (Reasoning) generates output significantly faster at 246 tok/s compared to GPT-5.3 Codex (xhigh)'s 72 tok/s, making it 3.4x faster for streaming responses. Time to first token is 11.75s for Grok 4.20 Beta 0309 (Reasoning) 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 Grok 4.20 Beta 0309 (Reasoning) costs $2.00/1M input ($6.00/1M output). 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 $12.00/month for Grok 4.20 Beta 0309 (Reasoning) in input costs alone.
Choose GPT-5.3 Codex (xhigh) when you need higher intelligence (54.0), stronger coding performance (53.1). Choose Grok 4.20 Beta 0309 (Reasoning) when you need faster output (246 tok/s).
GPT-5.3 Codex (xhigh) scores higher on coding benchmarks (53.1 vs 42.2), making it the better choice for programming tasks.
GPT-5.3 Codex (xhigh) is cheaper at $1.75/1M input tokens vs $2.00/1M for Grok 4.20 Beta 0309 (Reasoning).
Grok 4.20 Beta 0309 (Reasoning) is faster, producing output at 246 tok/s compared to GPT-5.3 Codex (xhigh)'s 72 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 |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Text |
| Output Modalities | Text | Text |
| Free Tier | No | No |
It depends on your priorities. GPT-5.3 Codex (xhigh) scores higher on intelligence (54.0), but Grok 4.20 Beta 0309 (Reasoning) may be better for specific use cases like budget-conscious projects or speed-critical applications.