Kimi K3.1 Pro vs Mercury 3
Mercury 3 comes out ahead, 67 to 46 on our weighted score, and it is the cheaper option too.
Moonshot AIKimi K3.1 Pro
46/100- ECI—
- Price$2.00 / $10.00
- Context1.05M
- Our pick
InceptionMercury 3
67/100- ECI—
- Price$0.10 / $0.35
- Context1M
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Make it a three-way comparison.
Mercury 3 is our pick
Mercury 3 is the better all-round choice, scoring 67/100 against Kimi K3.1 Pro (46). It leads on price. Kimi K3.1 Pro wins on inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceMercury 3Mercury 3 $0.163 · Kimi K3.1 Pro $4.00 per 1M tokens (3:1 blend)
- Longest contextKimi K3.1 ProKimi K3.1 Pro 1,048,576 · Mercury 3 1,000,000 tokens
- Widest inputsKimi K3.1 ProKimi K3.1 Pro: Text, Images, Video · Mercury 3: Text
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Kimi K3.1 Pro | Mercury 3 |
|---|---|---|---|
| Price | 50% | 20 | 84 |
| Inputs & features | 30% | 80 | 45 |
| Context window | 20% | 61 | 60 |
| Overall | 100% | 46/100 | 67/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Kimi K3.1 ProMoonshot AI | Mercury 3Inception |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $2.00 | $0.10 (best) |
| Output | $10.00 | $0.35 (best) |
| Cached input | $0.20 | $0.01 (best) |
| Blended (3:1) | $4.00 | $0.163 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official Moonshot AI API | Official Inception API |
| Limits | ||
| Context window | 1,048,576 tokens (best) | 1,000,000 tokens |
| Max output | 131,072 tokens | 131,072 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | No | No |
| Audio | No | No |
| Video | Yes | No |
| Reasoning | Yeslow · high · max | Yeslow · medium · high |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | kimi-k3.1-pro | mercury-3 |
| API providers | 17 (best) | 3 |
| Released | Oct 23, 2026 | Oct 16, 2026 |
| Knowledge cutoff | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Kimi K3.1 Pro$40.00
- Mercury 3$1.70
Which should you choose?
Which is better: Kimi K3.1 Pro or Mercury 3?
Mercury 3 is the better all-round choice, scoring 67/100 against Kimi K3.1 Pro (46). It leads on price. Kimi K3.1 Pro wins on inputs & features. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Kimi K3.1 Pro or Mercury 3?
Mercury 3 is cheaper at $0.10 input / $0.35 output per million tokens (official Inception API price). Kimi K3.1 Pro costs $2.00 input / $10.00 output per million tokens (official Moonshot AI API price). At a typical mix of three input tokens to one output token, that is $0.163 per million tokens for Mercury 3 versus $4.00 for Kimi K3.1 Pro (25× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Kimi K3.1 Pro has not been scored yet and Mercury 3 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Kimi K3.1 Pro and Mercury 3 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Kimi K3.1 Pro has the largest context window at 1,048,576 tokens, against 1,000,000 for Mercury 3. Maximum output per response: Kimi K3.1 Pro up to 131,072, Mercury 3 up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Kimi K3.1 Pro accepts text, images and video; Mercury 3 accepts text. Kimi K3.1 Pro handles the widest range of inputs.
Are any of these open source?
No. Kimi K3.1 Pro and Mercury 3 are proprietary and only available through APIs and apps.
Which is newer?
Kimi K3.1 Pro is the newest, released Oct 23, 2026. Mercury 3 came out Oct 16, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
