# Claude Fable 5.1 vs GPT-6 Astra

As of October 21, 2026, Claude Fable 5.1 and GPT-6 Astra cost the same: $10.00 per 1M input tokens and $50.00 per 1M output tokens. Claude Fable 5.1 has the larger context window: 1M tokens versus 922K.

- Page: https://models.litellm.ai/compare/claude-fable-5-1-vs-gpt-6-astra
- Claude Fable 5.1: https://models.litellm.ai/models/claude-fable-5-1
- GPT-6 Astra: https://models.litellm.ai/models/gpt-6-astra

## Side by side

| | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| Input, per 1M tokens | $10.00 | $10.00 |
| Output, per 1M tokens | $50.00 | $50.00 |
| Cache read, per 1M tokens | $0.25 | $1.00 |
| Cache write, per 1M tokens | $12.50 | $12.50 |
| 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 | 7 | 8 |
| Price shown is from | Anthropic | OpenAI |
| Added to LiteLLM | September 1, 2026 | September 3, 2026 |

Headline prices in USD per 1M tokens, from LiteLLM's model price file.

## Cheapest provider for each

- Claude Fable 5.1: Anthropic at $10.00 input per 1M tokens (`claude-fable-5-1`)
- GPT-6 Astra: OpenAI at $10.00 input per 1M tokens (`gpt-6-astra`)

## Benchmark scores

| Benchmark | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| Epoch Capabilities Index (Overall) | 166.5 | 168.8 |
| FrontierCode (Coding and agents) | 50.9% (medium) | 53.3% (max) |
| FrontierSWE (Coding and agents) | 56.3% (max) | 65.5% (max) |
| APEX-Agents (Coding and agents) | 68.6% | 64.7% |
| ARC-AGI-2 (Reasoning and knowledge) | 90.0% (max) | 95.0% (max) |
| SimpleQA Verified (Reasoning and knowledge) | 70.8% (max) | 75.6% (max) |
| FrontierMath (tiers 1-3) (Math) | 90.2% (max) | 93.7% (max) |
| FrontierMath (tier 4) (Math) | 87.8% (max) | 97.6% (high) |
| OTIS Mock AIME 2024-2025 (Math) | 100.0% (max) | 100.0% (max) |

From the Epoch AI Benchmarking Hub (https://epoch.ai/benchmarks), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/), data as of September 3, 2026: Epoch's own runs and results it collects from each benchmark's leaderboard. Higher is better.

## FAQ

### Which is cheaper, Claude Fable 5.1 or GPT-6 Astra?

They cost the same: $10.00 per 1M input tokens and $50.00 per 1M output tokens, as of October 21, 2026.

### Which has the larger context window, Claude Fable 5.1 or GPT-6 Astra?

Claude Fable 5.1 has the larger context window: 1,000,000 tokens, versus 922,000 for GPT-6 Astra.

### Can I switch from Claude Fable 5.1 to GPT-6 Astra 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-astra", or pointing a LiteLLM gateway model alias at the other model. You can also use one as a fallback for the other.