# Kimi K3.1 Pro vs Opus 5.5, GPT-6 Astra and More

> Six AI models compared on official API prices, independent evaluations and the availability of downloadable weights. Kimi's planned weights release is still pending.

By Arthur R. · Published 2026-10-29 · Updated 2026-10-29 · 8 min read · https://innvesti.com/reports/kimi-k3-1-pro-vs-claude-opus-gpt-6-astra-alternatives-2026/

## Quick answer

Kimi K3.1 Pro costs $2/$10 per million input/output tokens and scores 46 on Artificial Analysis's current Intelligence Index v5. It offers an interesting cost-versus-capability trade-off, but Sonnet scores higher at the same token rates, DeepSeek is cheaper, and Kimi's promised weights are not yet available.

## Key takeaways

- Moonshot offers Kimi K3.1 Pro through its apps and API and says full weights will be released by November 4, 2026. Check the actual weights and license before planning a self-hosted deployment.
- Kimi's official API rate is $2 input / $10 output per million tokens, matching Claude Sonnet 5.5's standard token rates. Sonnet's cache-read rate is lower.
- Artificial Analysis scored Kimi 55 and fourth at launch on October 23. After the October 27 change to Intelligence Index v5, its current score is 46, against 54 for Sonnet and 58 for Opus at maximum effort. Do not mix these index versions.
- The same Artificial Analysis v5 comparison estimates $3.68 per evaluated task for Kimi versus $10.02 for Sonnet at maximum effort. These benchmark costs are workload-specific, not a promise of lower bills for every application.
- DeepSeek V4.1 Flash-1017 and GLM-5.3 already have downloadable weights. DeepSeek's model files are MIT-licensed; GLM-5.3 uses a custom license with a condition for very large model-service providers.

## Key figures

- **$2 / $10** — Kimi K3.1 Pro official API input / output price per million tokens
- **46** — Kimi K3.1 Pro on Artificial Analysis Intelligence Index v5, checked October 29
- **Nov 4** — Moonshot's stated deadline for releasing K3.1 Pro weights in 2026

## Ranked

1. **Kimi K3.1 Pro** — Focus model; competitive token price, pending weights. https://platform.kimi.ai/
2. **Claude Sonnet 5.5** — Same token price, higher independent index score. https://www.anthropic.com/claude-sonnet-5-5
3. **DeepSeek V4.1 Flash-1017** — Lowest published API rate in this set. https://api-docs.deepseek.com/quick_start/pricing/
4. **Claude Opus 5.5** — Highest score in this set on the current index. https://www.anthropic.com/claude-opus-5-5
5. **GLM-5.3** — Downloadable weights under a custom license. https://huggingface.co/zai-org/GLM-5.3
6. **GPT-6 Astra** — Higher-cost closed model for demanding workloads. https://developers.openai.com/api/docs/models/gpt-6-astra

## Comparison

| Model | Standard API price (input / output per 1M) | Weight status | Intelligence Index v5 |
| --- | --- | --- | --- |
| Kimi K3.1 Pro | $2 / $10 | Promised by Nov 4; license not confirmed | 46 |
| Claude Sonnet 5.5 | $2 / $10 | Closed | 54 (max effort) |
| DeepSeek V4.1 Flash-1017 | $0.30 / $1.20 peak | Released, MIT | 32 (max effort) |
| Claude Opus 5.5 | $4 / $20 | Closed | 58 (max effort) |
| GLM-5.3 | See Z.ai rate card | Released, custom license | 32 (max effort) |
| GPT-6 Astra | $10 / $50; higher above 272K | Closed | 57 (max effort) |

## FAQ

### Is Kimi K3.1 Pro available now?

Yes. Moonshot lists Kimi K3.1 Pro in its apps and API. It says full model weights will be released by November 4, 2026; that is a future commitment, not proof that the files or license are available today.

### How much does the Kimi K3.1 Pro API cost?

The official international Kimi API page lists $2 per million input tokens, $10 per million output tokens and $0.20 per million cache hits for the standard model. The Highspeed variant costs $4/$20 for input/output tokens.

### Did Kimi score 55 or 46 on Artificial Analysis?

Both numbers describe different index versions. Artificial Analysis reported 55 and fourth place at launch on October 23. Its current Intelligence Index v5, introduced October 27, scores Kimi 46. Compare models within one index version.

### Are any Kimi model weights already available?

Yes. Moonshot's earlier Kimi K3 has published weights. This article's pending release refers specifically to Kimi K3.1 Pro weights. Do not assume K3 and K3.1 Pro have the same weights or license.

### Which compared model can be self-hosted under MIT?

DeepSeek's V4.1 Flash-1017 model repository includes an MIT license. GLM-5.3 has released weights but uses its own license. Check hardware needs and the actual license files before deployment.

### How should I compare API costs?

Start with the providers' current price pages, then run your own prompts and count total input, output and cached tokens. Standard per-token prices do not predict task cost when models use different numbers of tokens or retries.

## How we evaluated

We checked product availability, USD API rates and weight/license status against Moonshot, Anthropic, OpenAI, DeepSeek and the model publishers' Hugging Face repositories on October 29, 2026. Scores and benchmark task costs come from Artificial Analysis's own launch report, v5 announcement and current comparison page, with index versions kept separate. Its v5 score is a composite, not proof of superiority on every workload. Moonshot's vendor-reported Terminal-Bench and cyber figures were not used to assign rankings; the latter cannot establish why a different vendor scored differently on another test. The list starts with Kimi because it is the subject, then shows alternatives by use case rather than a universal quality ordering. Pricing can change, so confirm rates and run a workload test before choosing a provider.

- First-party published API prices and any long-context conditions
- Independent results compared within the same index version
- Downloadable weights and published license terms
- Practical fit for buyer workloads rather than a universal winner

## Sources

- [Moonshot — Kimi K3.1 Pro technical announcement and weights plan](https://www.kimi.ai/blog/kimi-k3-1-pro)
- [Kimi API — official USD model prices](https://platform.kimi.ai/)
- [Artificial Analysis — October 23 launch snapshot](https://artificialanalysis.ai/articles/kimi-k3-1-pro-launch-benchmarks/)
- [Artificial Analysis — October 27 Intelligence Index v5 update](https://artificialanalysis.ai/articles/artificial-analysis-intelligence-index-v5)
- [Artificial Analysis — current Kimi and Sonnet comparison](https://artificialanalysis.ai/models/comparisons/kimi-k3-1-pro-vs-claude-sonnet-5-5)
- [Anthropic — Claude Sonnet 5.5 price and availability](https://www.anthropic.com/claude-sonnet-5-5)
- [Anthropic — Claude Opus 5.5 price and availability](https://www.anthropic.com/claude-opus-5-5)
- [OpenAI — GPT-6 Astra model and pricing rules](https://developers.openai.com/api/docs/models/gpt-6-astra)
- [DeepSeek — API model versions and prices](https://api-docs.deepseek.com/quick_start/pricing/)
- [DeepSeek — V4.1 Flash-1017 model license](https://huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017/blob/main/LICENSE)
- [Z.ai — GLM-5.3 model weights and license](https://huggingface.co/zai-org/GLM-5.3/blob/main/LICENSE)
- [Moonshot — Kimi K3 model weights](https://huggingface.co/moonshotai/Kimi-K3)