Grok 4.3 vs Claude Fable 5.1: price, context window and capabilities
Grok 4.3 (x-ai/grok-4.3) from SpaceXAI and Claude Fable 5.1 (anthropic/claude-fable-5.1) from Anthropic are both multimodal language models on the OceanToken API. Grok 4.3 costs less per token than Claude Fable 5.1: $1.25 against $9.00 per 1M input tokens (86% less) and $2.50 against $45.00 per 1M output tokens (94% less). Claude Fable 5.1 is 10% off its 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 | Grok 4.3 | Claude Fable 5.1 −10% |
|---|---|---|
| Model | Grok 4.3x- | Claude Fable 5.1anthropic/ |
| Publisher | SpaceXAI | Anthropic |
| Kind | Text & vision | Text & vision |
| Context window | 1M tokens1,000,000 | 1M tokens1,000,000 |
| Input price | $1.25 / 1M tokens | $9.00 / 1M tokens |
| Output price | $2.50 / 1M tokens | $45.00 / 1M tokens |
| Cached input price | $0.20 / 1M tokens | $0.25 / 1M tokens |
| Web search price | $0.005 / search | $0.01 / search |
| Cache write price | – | $12.50 / 1M tokens |
| Discount (vs official, top tier) | — | −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 Grok 4.3 to spend less per token: 86% less for input and 94% less for output than Claude Fable 5.1.
- 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 Grok 4.3 Claude Fable 5.1
Frequently asked questions
Which is cheaper, Grok 4.3 or Claude Fable 5.1?
Grok 4.3. Grok 4.3 costs less per token than Claude Fable 5.1: $1.25 against $9.00 per 1M input tokens (86% less) and $2.50 against $45.00 per 1M output tokens (94% less). Claude Fable 5.1 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, Grok 4.3 or Claude Fable 5.1?
Neither. Both have a 1M-token context window (1,000,000 tokens).
Can I call both Grok 4.3 and Claude Fable 5.1 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 x-ai/grok-4.3 or anthropic/claude-fable-5.1.
Models and publishers
Grok 4.3 · Claude Fable 5.1 · All SpaceXAI models · All Anthropic models
More comparisons
DeepSeek V4.1 Flash vs Claude Fable 5.1 · DeepSeek V4 Pro vs Claude Fable 5.1 · DeepSeek V3.2 vs Claude Fable 5.1 · GLM 5.3 Prime vs Claude Fable 5.1 · All comparisons