Kimi K3 vs GPT-6 Astra: price, context window and capabilities
Kimi K3 (moonshotai/kimi-k3) from MoonshotAI and GPT-6 Astra (openai/gpt-6-astra) from OpenAI are both multimodal language models on the OceanToken API. Kimi K3 costs less per token than GPT-6 Astra: $3.00 against $9.00 per 1M input tokens (67% less) and $15.00 against $45.00 per 1M output tokens (67% less). GPT-6 Astra is 10% off its official price on OceanToken, for every account. Their context windows are almost the same size, about 1.05M tokens: GPT-6 Astra takes 1,050,000 tokens and Kimi K3 1,048,576. Both support tool calling, reasoning, structured outputs and image input; only Kimi K3 also lists video input; only GPT-6 Astra also lists file input.
Side by side
| Spec | Kimi K3 | GPT-6 Astra −10% |
|---|---|---|
| Model | Kimi K3moonshotai/ | GPT-6 Astraopenai/ |
| Publisher | MoonshotAI | OpenAI |
| Kind | Text, vision & video | Text & vision |
| Context window | 1.05M tokens1,048,576 | 1.05M tokens1,050,000 |
| Input price | $3.00 / 1M tokens | $9.00 / 1M tokens |
| Output price | $15.00 / 1M tokens | $45.00 / 1M tokens |
| Cached input price | $0.30 / 1M tokens | $1.00 / 1M tokens |
| Cache write price | – | $12.50 / 1M tokens |
| Web search price | – | $0.01 / search |
| Discount (vs official, top tier) | — | −10% |
| Inputs | text, images and video | text, images and files |
| Outputs | text | text |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Structured outputs | Yes | Yes |
About these prices
Which should you choose?
- Choose Kimi K3 to spend less per token: 67% less for input and 67% less for output than GPT-6 Astra.
- Context size does not separate them: both hold about 1.05M tokens.
- Choose Kimi K3 if you need video input: GPT-6 Astra does not list it.
- Not sure? Call both with the same OceanToken API key and compare them on your own prompts; each request is billed per use from one prepaid balance.
Get API Key Kimi K3 GPT-6 Astra
Frequently asked questions
Which is cheaper, Kimi K3 or GPT-6 Astra?
Kimi K3. Kimi K3 costs less per token than GPT-6 Astra: $3.00 against $9.00 per 1M input tokens (67% less) and $15.00 against $45.00 per 1M output tokens (67% less). GPT-6 Astra is 10% off its official price on OceanToken, for every account. The OceanToken console always shows the current price.
Which has the larger context window, Kimi K3 or GPT-6 Astra?
GPT-6 Astra, by 1,424 tokens. Their context windows are almost the same size, about 1.05M tokens: GPT-6 Astra takes 1,050,000 tokens and Kimi K3 1,048,576.
Can I call both Kimi K3 and GPT-6 Astra with one API key?
Yes. Both are on the OceanToken API at https://api.oceantoken.ai/v1: one API key and one prepaid balance call either model. Send the model id moonshotai/kimi-k3 or openai/gpt-6-astra.
Models and publishers
Kimi K3 · GPT-6 Astra · All MoonshotAI models · All OpenAI models
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