GPT-5.1 High vs Grok 4.5: Specs & Benchmark Comparison
GPT-5.1 High is developed by OpenAI, while Grok 4.5 comes from xAI. GPT-5.1 High was released in November 2025, and Grok 4.5 followed 8 months later in July 2026.
We have 3 benchmark results for GPT-5.1 High and 15 benchmark results for Grok 4.5, but they overlap on a single test: GPQA, where Grok 4.5 scores 93.0% against 88.0%.
On price the two are close: GPT-5.1 High costs $2 per million input tokens and $8 per million output tokens, Grok 4.5 $2 and $6. Grok 4.5 takes the larger context window at 500K tokens, compared with 256K for GPT-5.1 High. Both accept text and images as input.
| Characteristic | GPT-5.1 High | Grok 4.5 |
|---|---|---|
| Company | OpenAI | xAI |
| Release Date | November 11, 2025 | July 16, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 256K | 500K |
| Context (output) | 128K | — |
| Input Price / 1M | $2.00 | $2.00 |
| Output Price / 1M | $8.00 | $6.00 |
| Average Score | 86.7% | 52.9% |
| Benchmarks | ||
| GPQA | 88.0% | 93.0% |
Visual Benchmark Comparison
Verdict
Grok 4.5 leads in 3 out of 4 comparison categories.
Both models show comparable average scores: GPT-5.1 High — 0.9, Grok 4.5 — 0.5.
Grok 4.5 is 1.3x cheaper: input $2.00/1M vs $2.00/1M tokens.
Grok 4.5 supports a larger context: 500K vs 256K tokens.
Grok 4.5 is newer: released 7/16/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GPT-5.1 High or Grok 4.5?
Which model is cheaper — GPT-5.1 High or Grok 4.5?
Which has a larger context window — GPT-5.1 High or Grok 4.5?
The GPT-5.1 High and Grok 4.5 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.1 High or Grok 4.5 page. See also the complete list of AI model comparisons.