Kimi K3 vs Claude Opus 5.5: price, context window and capabilities
Kimi K3 (moonshotai/kimi-k3) from MoonshotAI and Claude Opus 5.5 (anthropic/claude-opus-5.5) from Anthropic are both multimodal language models on the OceanToken API. Kimi K3 costs less per token than Claude Opus 5.5: $3.00 against $3.60 per 1M input tokens (17% less) and $15.00 against $18.00 per 1M output tokens (17% less). Claude Opus 5.5 is 10% off its official price on OceanToken, for every account. Kimi K3 has the larger context window: 1.05M tokens (1,048,576) against 1M (1,000,000) for Claude Opus 5.5. Both support tool calling, reasoning, structured outputs and image input; only Kimi K3 also lists video input; only Claude Opus 5.5 also lists file input.
Side by side
| Spec | Kimi K3 | Claude Opus 5.5 −10% |
|---|---|---|
| Model | Kimi K3moonshotai/ | Claude Opus 5.5anthropic/ |
| Publisher | MoonshotAI | Anthropic |
| Kind | Text, vision & video | Text & vision |
| Context window | 1.05M tokens1,048,576 | 1M tokens1,000,000 |
| Input price | $3.00 / 1M tokens | $3.60 / 1M tokens |
| Output price | $15.00 / 1M tokens | $18.00 / 1M tokens |
| Cached input price | $0.30 / 1M tokens | $0.20 / 1M tokens |
| Cache write price | – | $5.00 / 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: 17% less for input and 17% less for output than Claude Opus 5.5.
- Choose Kimi K3 for the longest inputs: its context window holds 1.05M tokens against 1M for Claude Opus 5.5.
- Choose Kimi K3 if you need video input: Claude Opus 5.5 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 Claude Opus 5.5
Frequently asked questions
Which is cheaper, Kimi K3 or Claude Opus 5.5?
Kimi K3. Kimi K3 costs less per token than Claude Opus 5.5: $3.00 against $3.60 per 1M input tokens (17% less) and $15.00 against $18.00 per 1M output tokens (17% less). Claude Opus 5.5 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 Claude Opus 5.5?
Kimi K3. Kimi K3 has the larger context window: 1.05M tokens (1,048,576) against 1M (1,000,000) for Claude Opus 5.5.
Can I call both Kimi K3 and Claude Opus 5.5 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 anthropic/claude-opus-5.5.
Models and publishers
Kimi K3 · Claude Opus 5.5 · All MoonshotAI models · All Anthropic models
More comparisons
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