GPT-5 nano vs Grok 4.5
GPT-5 nano (OpenAI) and Grok 4.5 (xAI) compared on benchmarks, pricing, context window, and use-case rankings.
- Grok 4.5 leads on overall intelligence (ECI 154 vs 141).
- GPT-5 nano is cheaper on input tokens — $0.05 vs $2.00 per 1M.
- Grok 4.5 has a larger context window (500K vs 400K tokens).
- Grok 4.5 ranks higher for coding (91th vs 28th percentile).
| Attribute | GPT-5 nano | Grok 4.5 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 141 | 154 |
| Coding | 28 | 91 |
| Math | 13 | 85 |
| Reasoning & Knowledge | 7 | 70 |
| Agentic & Tools | 11 | 75 |
| Specifications | ||
| Developer | OpenAI | xAI |
| Family | GPT | Grok |
| Released | Aug 7, 2025 | Jul 8, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 400K | 500K |
| Price — $/M input | $0.05 | $2.00 |
| Price — $/M output | $0.40 | $6.00 |
| Inputs | text, image, file | text, image, file |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 81% | 98% |
| ARC-AGI | 21% | 87% |
| ARC-AGI-2 | 3% | 53% |
| FrontierMath | 8% | — |
| FrontierMath Tier 4 | 2% | — |
| GPQA Diamond | 69% | 93% |
| Humanity's Last Exam | 8% | 40% |
| LiveCodeBench | 79% | — |
| MATH Level 5 | 95% | — |
| MMLU-Pro | 78% | — |
| SciCode | 37% | 54% |
| SimpleQA Verified | 12% | 54% |
| Terminal-Bench | 22% | — |
| WeirdML | 38% | 46% |
| τ²-bench | 37% | — |
| APEX | — | 34% |
| SimpleBench | — | 70% |
| WebDev Arena | — | 1551 |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is GPT-5 nano better than Grok 4.5?
On Epoch AI's Capabilities Index, Grok 4.5 scores higher (154) than GPT-5 nano (141). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is cheaper, GPT-5 nano or Grok 4.5?
GPT-5 nano is cheaper on input tokens at $0.05 per million, versus $2.00 (representative OpenRouter pricing).
Which has a larger context window, GPT-5 nano or Grok 4.5?
Grok 4.5 supports up to 500K tokens, compared with 400K for the other.
Which is better for coding, GPT-5 nano or Grok 4.5?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Grok 4.5 ranks higher — 91th vs 28th percentile among the models tracked on Model Beat.
Want a different match-up? Open the compare tool to add or swap models.
More comparisons
Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.