GPT-5.1 Medium vs Grok 4.5: Specs & Benchmark Comparison
GPT-5.1 Medium is developed by OpenAI, while Grok 4.5 comes from xAI. GPT-5.1 Medium was released in November 2025, and Grok 4.5 followed 8 months later in July 2026.
We have 1 benchmark result for GPT-5.1 Medium and 15 benchmark results for Grok 4.5, but they were measured on different benchmarks, so there is no like-for-like scoreboard.
GPT-5.1 Medium is the cheaper API at $1 per million input tokens and $4 per million output tokens, roughly 2 times cheaper than Grok 4.5 at $2 and $6. Grok 4.5 takes the larger context window at 500K tokens, compared with 256K for GPT-5.1 Medium. Both accept text and images as input.
| Characteristic | GPT-5.1 Medium | Grok 4.5 |
|---|---|---|
| Company | OpenAI | xAI |
| Release Date | November 11, 2025 | July 16, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 256K | 500K |
| Context (output) | 64K | — |
| Input Price / 1M | $1.00 | $2.00 |
| Output Price / 1M | $4.00 | $6.00 |
| Average Score | 98.0% | 52.9% |
Verdict
Grok 4.5 leads in 2 out of 4 comparison categories.
Both models show comparable average scores: GPT-5.1 Medium — 1.0, Grok 4.5 — 0.5.
GPT-5.1 Medium is 1.6x cheaper: input $1.00/1M 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 Medium or Grok 4.5?
Which model is cheaper — GPT-5.1 Medium or Grok 4.5?
Which has a larger context window — GPT-5.1 Medium or Grok 4.5?
The GPT-5.1 Medium 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 Medium or Grok 4.5 page. See also the complete list of AI model comparisons.