Claude Fable 5.1 vs GPT-6 Rosalind
As of November 10, 2026, GPT-6 Rosalind costs 50% more per input token than Claude Fable 5.1 ($15.00 vs $10.00 per 1M) and has a 922K-token context window versus 1M.
Claude Fable 5.1 vs GPT-6 Rosalind side by side
| Claude Fable 5.1 | GPT-6 Rosalind | |
|---|---|---|
| Input, per 1M tokens | $10.00 | $15.00 |
| Output, per 1M tokens | $50.00 | $75.00 |
| Cache read, per 1M tokens | $0.25 | $1.50 |
| Cache write, per 1M tokens | $12.50 | $18.75 |
| Context window | 1,000,000 tokens | 922,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Image input | Yes | Yes |
| Tool calling | Yes | Yes |
| Structured output (JSON) | Yes | Yes |
| Prompt caching | Yes | Yes |
| Reasoning | Yes | Yes |
| Providers on LiteLLM | 8 | 2 |
| Price shown is from | Anthropic | OpenAI |
| Added to LiteLLM | September 1, 2026 | October 30, 2026 |
Cheapest provider for each
- Claude Fable 5.1: Databricks at $10.00 input and $50.00 output per 1M tokens (
databricks/databricks-claude-fable-5-1) - GPT-6 Rosalind: OpenAI at $15.00 input and $75.00 output per 1M tokens (
gpt-6-rosalind)
When to pick which
Pick Claude Fable 5.1 for
- Costs 33% less per input token: $10.00 vs $15.00 per 1M.
- Available from 8 providers through LiteLLM, vs 2.
From differences in the data above only; where the data is equal, no reason is given.
Call Claude Fable 5.1 or GPT-6 Rosalind with LiteLLM
Both use the OpenAI format through LiteLLM, so switching is a model name change. Set each provider's API key in the environment first.
from litellm import completion
messages = [{"role": "user", "content": "Hello!"}]
# Claude Fable 5.1
response = completion(model="claude-fable-5-1", messages=messages)
# GPT-6 Rosalind
response = completion(model="gpt-6-rosalind", messages=messages)
# Claude Fable 5.1, falling back to GPT-6 Rosalind if the call fails
response = completion(model="claude-fable-5-1", messages=messages, fallbacks=["gpt-6-rosalind"])FAQ
Which is cheaper, Claude Fable 5.1 or GPT-6 Rosalind?
Claude Fable 5.1 is cheaper at 3 input tokens per output token: $20.00 per 1M tokens blended ($10.00 input, $50.00 output), versus $30.00 ($15.00 and $75.00) for GPT-6 Rosalind, as of November 10, 2026.
Which has the larger context window, Claude Fable 5.1 or GPT-6 Rosalind?
Claude Fable 5.1 has the larger context window: 1,000,000 tokens, versus 922,000 for GPT-6 Rosalind.
Can I switch from Claude Fable 5.1 to GPT-6 Rosalind without changing my code?
Yes. Through LiteLLM both use the OpenAI format, so switching means changing the model name from "claude-fable-5-1" to "gpt-6-rosalind", or pointing a LiteLLM gateway model alias at the other model. You can also use one as a fallback for the other.