DeepSeek V3.1-Terminus vs Grok 4 Fast Reasoning
| Spec | DeepSeek V3.1-Terminus | Grok 4 Fast Reasoning |
|---|---|---|
| Respan Index | 20.6 (#114) | 20.4 (#116) |
| Blended price per 1M | $0.453 | - |
| Context window | 128K | 2M |
| Input / output per 1M | $0.27 / $1 | - |
| Max output | - | - |
| Input | text | text |
| Released | 2025-09-22 | 2025-09-19 |
Respan Index by category
Each category is scored 0 to 100, and how far ahead the winner is. Leads under a point are close to even.
| Category | DeepSeek V3.1-Terminus | Grok 4 Fast Reasoning |
|---|---|---|
| Coding | 5.2 DeepSeek V3.1-Terminus | 5.0* Grok 4 Fast Reasoning |
| Agents | 15.5 DeepSeek V3.1-Terminus | 18.7 Grok 4 Fast Reasoning |
| Reasoning | 25.3 DeepSeek V3.1-Terminus | 25.5 Grok 4 Fast Reasoning |
| Knowledge & language | 19.6 DeepSeek V3.1-Terminus | 14.5* Grok 4 Fast Reasoning |
| Human preference | 47.3 DeepSeek V3.1-Terminus | 44.2 Grok 4 Fast Reasoning |
* Estimated: no published scores in that category. How the Respan Index works
Benchmarks both report
DeepSeek V3.1-Terminus leads on 2 of the 3 benchmarks both report. Higher is better. Each score links to where it was published.
FAQ
Is DeepSeek V3.1-Terminus better than Grok 4 Fast Reasoning?
DeepSeek V3.1-Terminus scores 20.6 on the Respan Index (#114), ahead of Grok 4 Fast Reasoning at 20.4 (#116). DeepSeek V3.1-Terminus leads on 2 of the 3 benchmarks both report.
Which has the larger context window?
DeepSeek V3.1-Terminus accepts 128K tokens and Grok 4 Fast Reasoning 2M tokens.