GPT-5 Pro vs Grok 4.3
GPT-5 Pro 
Grok 4.3 Verdict
- GPT-5 Pro and Grok 4.3 (medium) are level on quality (60.8 vs 60.7).
- GPT-5 Pro is stronger in multimodal, reasoning.
- Grok 4.3 (medium) is stronger in knowledge, agents & tools, composite, instruction following, long context.
- Grok 4.3 (medium) is 26× cheaper ($1.56 vs $41.25 per 1M blended).
| Metric | GPT-5 Pro | Grok 4.3 (medium) |
|---|---|---|
| BenchLeader Index | 60.8 | 60.7 |
| Knowledge score | 68.0 | 72.1 |
| Multimodal score | 67.4 | 60.2 |
| Reasoning score | 57.6 | – |
| Agents & tools score | – | 60.1 |
| Composite score | – | 60.3 |
| Instruction following score | – | 80.0 |
| Long context score | – | 64.0 |
| Blended price $/M | $41.25 | $1.56 |
| Output speed | – | 112 tok/s |
| Time to first answer | – | 12.1 s |
| Context window | 400k | 1M |
| Humanity's Last Exam | 31.6% | – |
| SimpleBench | 61.6% | – |
| Epoch Capabilities Index | 150.3 | – |
| AA Intelligence Index | – | 24.8 |
| IFBench | – | 83.3% |
| AA-LCR | – | 75.0% |
| MMMU-Pro | – | 75.8% |
| AA-Omniscience | – | 16.7 |
| Terminal-Bench Hard | – | 30.3% |
| GPQA Diamond (AA) | – | 89.0% |
| Humanity's Last Exam (AA) | – | 30.0% |
| τ²-Bench Telecom (AA) | – | 91.2% |
| PRBench Finance | 51.1% | – |
| PRBench Legal | 49.9% | – |
| VISTA | 52.4% | – |
| MultiNRC | 65.2% | – |
| Kagi LLM Benchmark | 76.8% | – |
| ARC-AGI-1 | 70.2% | – |
| ARC-AGI-2 | 18.3% | – |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
GPT-5 Pro vs Grok 4.3: questions
- Is GPT-5 Pro better than Grok 4.3?
- GPT-5 Pro and Grok 4.3 (medium) are level on quality (60.8 vs 60.7). The BenchLeader Index combines every independent quality benchmark; GPT-5 Pro is ahead overall as of 2026-09-10, but check the category scores for your use.
- Which is cheaper, GPT-5 Pro or Grok 4.3?
- Grok 4.3 is cheaper: $1.56 against $41.25 per million tokens, blended at three input tokens per output token.
- Which has the larger context window?
- Grok 4.3 accepts more context: 1M against 400k tokens.