Gemini 3.8 Flash vs Kimi K3.1 Pro
A side-by-side comparison of Gemini 3.8 Flash from Google and Kimi K3.1 Pro from Moonshot AI, using published pricing, context windows, supported inputs, and release dates.
- Gemini 3.8 Flash input
- $0.825
- Kimi K3.1 Pro input
- $2
Key differences
Gemini 3.8 Flash is 59% cheaper on input tokens ($0.825 vs $2 per 1M).
Kimi K3.1 Pro is the newer release (Oct 23, 2026, vs Sep 2, 2026).
Gemini 3.8 Flash vs Kimi K3.1 Pro specs
| Spec | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Provider | Moonshot AI | |
| Released | Sep 2, 2026 | Oct 23, 2026 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Input price / 1M tokens | $0.825 | $2 |
| Output price / 1M tokens | $4.13 | $10 |
| 10K in + 1K out request | $0.012 | $0.03 |
| Accepts | audio, file, image, text, video | image, text, video |
| Produces | text | text |
| Tool calling | Yes | Yes |
| Structured outputs | Yes | Yes |
| Reasoning | Yes | Yes |
| Popularity | 39/100 | 41/100 |
Highlighted values are better on that spec: lower price, larger context window, newer release, or higher popularity. Prices in USD per 1M tokens as listed on OpenRouter.
Gemini 3.8 Flash vs Kimi K3.1 Pro questions
Is Gemini 3.8 Flash or Kimi K3.1 Pro cheaper?
Gemini 3.8 Flash has the lower listed input price ($0.825 per million tokens). For a request with 10,000 input and 1,000 output tokens, Gemini 3.8 Flash costs about $0.012 and Kimi K3.1 Pro about $0.03.
Which model should I choose?
Pick the cheaper model for high-volume, simpler tasks, and test both on a sample of your real prompts before committing. Price and context size do not measure output quality on your specific workload.