Claude Opus 5.5 vs Claude Sonnet 5.5: price, context window and capabilities
Claude Opus 5.5 (anthropic/claude-opus-5.5) and Claude Sonnet 5.5 (anthropic/claude-sonnet-5.5) are both multimodal language models from Anthropic on the OceanToken API. Claude Sonnet 5.5 costs less per token than Claude Opus 5.5: $1.80 against $3.60 per 1M input tokens (50% less) and $9.00 against $18.00 per 1M output tokens (50% less). Both are 10% off their official price on OceanToken, for every account. Both have a 1M-token context window (1,000,000 tokens). Both support tool calling, reasoning, structured outputs, image input and file input.
Side by side
| Spec | Claude Opus 5.5 −10% | Claude Sonnet 5.5 −10% |
|---|---|---|
| Model | Claude Opus 5.5anthropic/ | Claude Sonnet 5.5anthropic/ |
| Publisher | Anthropic | Anthropic |
| Kind | Text & vision | Text & vision |
| Context window | 1M tokens1,000,000 | 1M tokens1,000,000 |
| Input price | $3.60 / 1M tokens | $1.80 / 1M tokens |
| Output price | $18.00 / 1M tokens | $9.00 / 1M tokens |
| Cached input price | $0.20 / 1M tokens | $0.10 / 1M tokens |
| Cache write price | $5.00 / 1M tokens | $2.50 / 1M tokens |
| Web search price | $0.01 / search | $0.01 / search |
| Discount (vs official, top tier) | −10% | −10% |
| Inputs | text, images and files | 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 Claude Sonnet 5.5 to spend less per token: 50% less for input and 50% less for output than Claude Opus 5.5.
- Context size does not separate them: both hold about 1M tokens.
- Both list the same capabilities: tool calling, reasoning, structured outputs, image input and file input.
- 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 Claude Opus 5.5 Claude Sonnet 5.5
Frequently asked questions
Which is cheaper, Claude Opus 5.5 or Claude Sonnet 5.5?
Claude Sonnet 5.5. Claude Sonnet 5.5 costs less per token than Claude Opus 5.5: $1.80 against $3.60 per 1M input tokens (50% less) and $9.00 against $18.00 per 1M output tokens (50% less). Both are 10% off their official price on OceanToken, for every account. The OceanToken console always shows the current price.
Which has the larger context window, Claude Opus 5.5 or Claude Sonnet 5.5?
Neither. Both have a 1M-token context window (1,000,000 tokens).
Can I call both Claude Opus 5.5 and Claude Sonnet 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 anthropic/claude-opus-5.5 or anthropic/claude-sonnet-5.5.
Models and publishers
Claude Opus 5.5 · Claude Sonnet 5.5 · All Anthropic models
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