GPT-5.3-Codex vs GPT-6 Sol
GPT-5.3-Codex Verdict
- GPT-6 Sol (max) leads on quality: 67.7 vs 64.6.
- GPT-5.3-Codex (xhigh) is stronger in agents & tools, coding, instruction following.
- GPT-6 Sol (max) is stronger in composite, knowledge, long context, multimodal, reasoning.
- GPT-6 Sol (max) is 1.2× cheaper ($4.00 vs $4.81 per 1M blended).
| Metric | GPT-5.3-Codex (xhigh) | GPT-6 Sol (max) |
|---|---|---|
| BenchLeader Index | 64.6 | 67.7 |
| Agents & tools score | 79.8 | – |
| Coding score | 61.5 | – |
| Composite score | 68.2 | 86.2 |
| Instruction following score | 73.4 | – |
| Knowledge score | 67.9 | 75.4 |
| Long context score | 67.5 | 67.7 |
| Multimodal score | 62.2 | 67.1 |
| Reasoning score | 71.5 | 95.0 |
| Blended price $/M | $4.81 | $4.00 |
| Output speed | 148 tok/s | 126 tok/s |
| Time to first answer | 54.7 s | 107.2 s |
| Context window | 400k | 1.1M |
| WeirdML | 77.9% | – |
| AA Intelligence Index | 32.5 | 47.5 |
| IFBench | 75.4% | – |
| AA-LCR | 83.3% | 83.7% |
| MMMU-Pro | 78.5% | 83.3% |
| AA-Omniscience | 10.9 | 27.1 |
| Terminal-Bench Hard | 53.0% | – |
| GPQA Diamond (AA) | 91.5% | – |
| Humanity's Last Exam (AA) | 42.5% | 47.9% |
| SciCode (AA) | – | 57.6% |
| τ²-Bench Telecom (AA) | 86.0% | – |
| LiveCodeBench | 87.3% | – |
| IOI | 53.8% | – |
| SWE-bench (Vals) | 78.0% | – |
| CritPt | 16.9% | 30.9% |
| GDPval (AA) | – | 49.4% |
| Vibe Code Bench v1.1 | 61.8% | – |
| ALE-Bench | 1655.2 | – |
| Terminal-Bench 4.0 (AA) | – | 43.9% |
| AutomationBench | – | 61.6% |
| GDP.pdf | – | 24.8% |
| MLCR | – | 16.1% |
| AA-Omniscience: accuracy | 52.9% | 54.5% |
| AA-Omniscience: non-hallucination | 10.8% | 39.9% |
| AA-Briefcase | – | 1483 |
Data as of 2026-09-23. Best configuration of each model; every score links to its source on the model pages.
GPT-5.3-Codex vs GPT-6 Sol: questions
- Is GPT-5.3-Codex better than GPT-6 Sol?
- GPT-6 Sol (max) leads on quality: 67.7 vs 64.6. The BenchLeader Index combines every independent quality benchmark; GPT-6 Sol (max) is ahead overall as of 2026-09-23, but check the category scores for your use.
- Which is cheaper, GPT-5.3-Codex or GPT-6 Sol?
- GPT-6 Sol is cheaper: $4.00 against $4.81 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.3-Codex or GPT-6 Sol?
- GPT-5.3-Codex streams faster: 148 against 126 output tokens per second.
- Which has the larger context window?
- GPT-6 Sol accepts more context: 1.1M against 400k tokens.