Gemini 3.5 Flash vs Kimi K3
Google's Gemini 3.5 Flash and Moonshot AI's Kimi K3 both target production language workloads, but they price and behave differently. Here is the side-by-side.
Pricing checked against provider documentation on . How we verify
The short answer
Gemini 3.5 Flash is the cheaper option — roughly 1.8x less on a blended workload, and it suits agentic loops and sub-agent fleets. Kimi K3 justifies its premium when you need natively multimodal long-horizon agents.
Google • Gemini 3.5
$1.50 / $9.00
/ 1M tokens (input / output)
Google's most capable Flash model, tuned for the agentic era: sub-agent deployment, multi-step workflows, and rapid coding iterations at scale. Supports search grounding, function calling, structured outputs, and computer use in preview. Note that it is pricier than the Gemini 3 Flash preview it replaced.
Moonshot AI • Kimi K
$3.00 / $15.00
/ 1M tokens (input / output)
At 2.8T total parameters with 104B active, Kimi K3 is the largest open-weight model in general circulation and the only one here that ingests video natively. Reasoning is always on with configurable effort. The licence is the catch: it is not a standard open licence, and organisations above $20M in revenue need a separate commercial agreement.
Input price
Kimi K3 is 2.0x the price than Gemini 3.5 Flash on input tokens.
Output price
Kimi K3 is 67% more expensive than Gemini 3.5 Flash on output tokens — usually the side that dominates the bill.
Monthly cost at three workload sizes
Standard (non-batch, non-cached) rates. Reasoning models will exceed these figures because thinking tokens bill as output.
| Workload | Gemini 3.5 Flash | Kimi K3 | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $3 | $6 | $3 |
| Moderate — 10M in / 2M out | $33 | $60 | $27 |
| Heavy — 100M in / 20M out | $330 | $600 | $270 |
Specification comparison
| Attribute | Gemini 3.5 Flash | Kimi K3 |
|---|---|---|
| Input (/ 1M tokens) | $1.50 | $3.00 |
| Output (/ 1M tokens) | $9.00 | $15.00 |
| Cached input | — | $0.30 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Max output | 65,536 tokens | 131,072 tokens |
| Native reasoning | Yes | Yes |
| Knowledge cutoff | 2025-01 | 2026-02 |
| Relative latency | low | high |
| Open weights | No | Kimi K3 License (commercial terms above $20M revenue) |
| API model ID | gemini-3.5-flash | kimi-k3 |
| Status | stable | stable |
Gemini 3.5 Flash: Flat rate at any context length, unlike Gemini 3.1 Pro's 200K cliff.
Kimi K3: The custom licence requires a separate commercial agreement once the licensee and its affiliates exceed $20M revenue over any consecutive 12 months.
Choose Gemini 3.5 Flash if…
- Sub-agent fleets and orchestration
- Fast coding iteration loops
- Search-grounded answers
- Multimodal ingestion at scale
Choose Kimi K3 if…
- Multimodal agent workflows
- Video and image understanding at length
- Ambitious long-horizon automation
- Research requiring open weights at scale
Frequently asked
Is Gemini 3.5 Flash or Kimi K3 cheaper?
Gemini 3.5 Flash is cheaper. On a blended 3:1 input-to-output workload it costs about 1.8x less than Kimi K3.
Which has the larger context window, Gemini 3.5 Flash or Kimi K3?
Both accept up to 1.05M tokens, so context is not a differentiator here.
Should I use Gemini 3.5 Flash or Kimi K3?
Pick Gemini 3.5 Flash for agentic loops and sub-agent fleets. Pick Kimi K3 for natively multimodal long-horizon agents. If cost dominates the decision, Gemini 3.5 Flash wins; if you need the capability ceiling, benchmark both on your own evals before committing.