// head_to_head
Gemini 3.5 Flash vs Kimi K3.1 Pro
Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.
Gemini 3.5 Flash is the cheaper of the two; neither can be ranked on quality here.
Gemini 3.5 Flash does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.
Gemini 3.5 Flash
- Blended / 1M
- $3.38
- Context
- 1.0M
- Released
- May 19, 2026
- Overall score
- Not evaluated
moonshotai
Kimi K3.1 Pro
- Blended / 1M
- $4.00
- Context
- 1.0M
- Released
- Oct 23, 2026
- Overall score
- 71.3
Specs and pricing
| Metric | Gemini 3.5 Flash | Kimi K3.1 Pro |
|---|---|---|
| LiveBench overall Weighted mean of the seven LiveBench category scores, 0–100. Higher is better. | — | 71.3 |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | — | $0.0104 |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $3.38win | $4.00 |
| Input price / 1M | $1.50win | $2.00 |
| Output price / 1M | $9.00win | $10.00 |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.150win | $0.200 |
| Context window | 1.0M | 1.0M |
| Max output tokens | 66K | 944Kwin |
Benchmarks by category
An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Gemini 3.5 Flash on top, Kimi K3.1 Pro below, both out of 100.
What each one costs to run
Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.
| Workload | Gemini 3.5 Flash | Kimi K3.1 Pro |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $982.80/mo | $1,150/mo |
| RAG assistant 8K in / 600 out × 100K requests | $1,200/mo | $1,480/mo |
| Coding agent 40K in / 4K out × 20K requests | $1,164/mo | $1,392/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $2,108/mo | $2,660/mo |
| Bulk classification 500 in / 20 out × 5M requests | $3,975/mo | $5,100/mo |
Which should you pick?
You are cost-constrained
Gemini 3.5 Flash
Cheaper on blended list price at $3.38 per million tokens.
Gemini 3.5 Flash vs Kimi K3.1 Pro FAQ
Which is better, Gemini 3.5 Flash or Kimi K3.1 Pro?
Gemini 3.5 Flash is the cheaper of the two; neither can be ranked on quality here. Gemini 3.5 Flash does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.
Is Gemini 3.5 Flash cheaper than Kimi K3.1 Pro?
Gemini 3.5 Flash is cheaper. On a 3:1 input:output blend, Gemini 3.5 Flash lists at $3.38 per million tokens and Kimi K3.1 Pro at $4.00 — Gemini 3.5 Flash is 19% cheaper. Input and output are priced separately — Gemini 3.5 Flash charges $1.50 in and $9.00 out, Kimi K3.1 Pro charges $2.00 and $10.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Does Gemini 3.5 Flash or Kimi K3.1 Pro have a bigger context window?
They are effectively the same — 1.0M for Gemini 3.5 Flash and 1.0M for Kimi K3.1 Pro.
Do Gemini 3.5 Flash and Kimi K3.1 Pro support prompt caching?
Both publish a cached-input rate: $0.150 per million for Gemini 3.5 Flash and $0.200 for Kimi K3.1 Pro, against full input rates of $1.50 and $2.00. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.
Related comparisons
How these numbers are produced
- Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
- Scores — LiveBench release 2026-10-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
- Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
- “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.
Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.