GPT-5.1 Codex High vs Grok 4.5: Specs & Benchmark Comparison
| Characteristic | GPT-5.1 Codex High | Grok 4.5 |
|---|---|---|
| Company | OpenAI | xAI |
| Release Date | November 11, 2025 | July 16, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 400K | 500K |
| Context (output) | 128K | — |
| Input Price / 1M | $1.25 | $2.00 |
| Output Price / 1M | $10.00 | $6.00 |
| Average Score | 1.0 | 0.8 |
Verdict
Grok 4.5 leads in 3 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: GPT-5.1 Codex High — 1.0, Grok 4.5 — 0.8.
API Cost
Grok 4.5 is 1.4x cheaper: input $2.00/1M vs $1.25/1M tokens.
Context Window
Grok 4.5 supports a larger context: 500K vs 400K tokens.
Recency
Grok 4.5 is newer: released 7/16/2026 vs 11/11/2025.
More About These Models
Related Comparisons
Frequently Asked Questions
Which is better for coding — GPT-5.1 Codex High or Grok 4.5?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GPT-5.1 Codex High or Grok 4.5?
GPT-5.1 Codex High is cheaper for input: $1.25 per 1M tokens vs $2.00.
Which has a larger context window — GPT-5.1 Codex High or Grok 4.5?
Grok 4.5 supports a larger context: 500,000 tokens vs 400,000.
The GPT-5.1 Codex 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 Codex High or Grok 4.5 page. See also the complete list of AI model comparisons.