GPT-5.1 vs Grok 4
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
GPT-5.1
59.6OpenAI · Nov 2025
A November 2025 update to GPT-5 with adaptive reasoning that spends thinking tokens only when a task needs them.
Grok 4
xAI · Jul 2025
xAI's mid-2025 flagship, trained on the 200K-GPU Colossus cluster — a math and science reasoning standout of its generation.
The verdict
GPT-5.1 wins 2 of the 2 benchmarks these models share, against 0 for Grok 4. GPT-5.1 is about 1.7x cheaper per blended million tokens (3:1 input:output mix). GPT-5.1 also takes 400K of context versus 256K for Grok 4.
Benchmark head-to-head 2–0
Specs & pricing
| GPT-5.1 | Grok 4 | |
|---|---|---|
| modhub Index | 59.6 | — |
| Input price / 1M | $1.25 | $3 |
| Output price / 1M | $10 | $15 |
| Context window | 400K | 256K |
| Max output | 128K | — |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Sep 2024 | Jul 2025 |
| Released | Nov 2025 | Jul 2025 |
| Example monthly cost* | $27.50 | $52.50 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GPT-5.1 or Grok 4?
- GPT-5.1 wins 2 of the 2 benchmarks these models share, against 0 for Grok 4. GPT-5.1 is about 1.7x cheaper per blended million tokens (3:1 input:output mix). GPT-5.1 also takes 400K of context versus 256K for Grok 4.
- Which is cheaper, GPT-5.1 or Grok 4?
- GPT-5.1 costs $1.25/$10 per million input/output tokens, while Grok 4 costs $3/$15. For a typical workload of 10M input and 1.5M output tokens per month, that's $27.50 versus $52.50.
- Which model is better for coding, GPT-5.1 or Grok 4?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.