DeepSeek V3.1 vs Gemini 2.5 Flash
| Spec | DeepSeek V3.1 | Gemini 2.5 Flash |
|---|---|---|
| Respan Index | 18.6 (#128) | 18.7 (#127) |
| Blended price per 1M | $0.425 | $0.85 |
| Context window | 128K | 1.0M |
| Input / output per 1M | $0.25 / $0.95 | $0.3 / $2.5 |
| Max output | - | 66K |
| Input | text | text, vision, audio |
| Released | 2025-08-21 | 2025-06-17 |
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 | Gemini 2.5 Flash |
|---|---|---|
| Coding | 4.9 DeepSeek V3.1 | 2.5 Gemini 2.5 Flash |
| Agents | 11.3 DeepSeek V3.1 | 18.5 Gemini 2.5 Flash |
| Reasoning | 23.9 DeepSeek V3.1 | 20.5 Gemini 2.5 Flash |
| Knowledge & language | 14.4* DeepSeek V3.1 | 13.6* Gemini 2.5 Flash |
| Human preference | 47.3 DeepSeek V3.1 | 46.7 Gemini 2.5 Flash |
* Estimated: no published scores in that category. How the Respan Index works
Benchmarks both report
DeepSeek V3.1 leads on 2 of the 2 benchmarks both report. Higher is better. Each score links to where it was published.
| Benchmark | DeepSeek V3.1 | Gemini 2.5 Flash |
|---|---|---|
| LMArena Elo | 1417 | 1409 |
| AIME 2025 | 90.8% | 72% |
FAQ
Is DeepSeek V3.1 better than Gemini 2.5 Flash?
Gemini 2.5 Flash scores 18.7 on the Respan Index (#127), ahead of DeepSeek V3.1 at 18.6 (#128). DeepSeek V3.1 leads on 2 of the 2 benchmarks both report.
Which is cheaper, DeepSeek V3.1 or Gemini 2.5 Flash?
DeepSeek V3.1 lists at $0.25 input and $0.95 output per 1M tokens; Gemini 2.5 Flash at $0.3 and $2.5. DeepSeek V3.1 is 2.0x cheaper per token at list price.
Which has the larger context window?
DeepSeek V3.1 accepts 128K tokens and Gemini 2.5 Flash 1.0M tokens.