Kimi K3.1 Pro vs Mercury 3 vs Pareto
Mercury 3 comes out ahead, 67 to 46 and 33 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
Unbiased
Pareto
33/100- ECI—
- Price$2.57 / $7.72
- Context262K
Mercury 3 is our pick
Mercury 3 is the better all-round choice, scoring 67/100 against Kimi K3.1 Pro (46) and Pareto (33). 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 · Pareto $3.86 · 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 · Pareto 262,144 tokens
- Widest inputsKimi K3.1 ProKimi K3.1 Pro: Text, Images, Video · Mercury 3: Text · Pareto: Text, Images
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Kimi K3.1 Pro | Mercury 3 | Pareto |
|---|---|---|---|---|
| Price | 50% | 20 | 84 | 21 |
| Inputs & features | 30% | 80 | 45 | 50 |
| Context window | 20% | 61 | 60 | 37 |
| Overall | 100% | 46/100 | 67/100 | 33/100 |
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 | ParetoUnbiased |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $2.00 | $0.10 (best) | $2.57 |
| Output | $10.00 | $0.35 (best) | $7.72 |
| Cached input | $0.20 | $0.01 (best) | — |
| Blended (3:1) | $4.00 | $0.163 (best) | $3.86 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Moonshot AI API | Official Inception API | Median of 2 providers |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 1,000,000 tokens | 262,144 tokens |
| Max output | 131,072 tokens | 131,072 tokens | 131,072 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | No | Yes |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | Yes | No | No |
| Reasoning | Yeslow · high · max | Yeslow · medium · high | No |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | kimi-k3.1-pro | mercury-3 | — |
| API providers | 17 (best) | 3 | 2 |
| Released | Oct 23, 2026 | Oct 16, 2026 | Sep 17, 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
- Pareto$41.16
Which should you choose?
Which is better: Kimi K3.1 Pro, Mercury 3 or Pareto?
Mercury 3 is the better all-round choice, scoring 67/100 against Kimi K3.1 Pro (46) and Pareto (33). 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, Mercury 3 or Pareto?
Mercury 3 is cheaper at $0.10 input / $0.35 output per million tokens (official Inception API price). Pareto costs $2.57 input / $7.72 output per million tokens (median across 2 API providers); 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 $3.86 for Pareto (24× as much) and $4.00 for Kimi K3.1 Pro (25× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Kimi K3.1 Pro has not been scored yet, Mercury 3 has not been scored yet and Pareto has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Kimi K3.1 Pro, Mercury 3 and Pareto yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three 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 and 262,144 for Pareto. Maximum output per response: Kimi K3.1 Pro up to 131,072, Mercury 3 up to 131,072, Pareto 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; Pareto accepts text and images. Kimi K3.1 Pro handles the widest range of inputs.
Are any of these open source?
No. Kimi K3.1 Pro, Mercury 3 and Pareto 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; Pareto came out Sep 17, 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.
