Model comparison - Similar price, same tier
Claude Fable 5.1 vs GPT-6 Astra
Claude Fable 5.1 is from Anthropic and GPT-6 Astra is from OpenAI. Both list the same first-party API price: $10 per 1M input tokens and $50 per 1M output tokens. Claude Fable 5.1 has a 1,000,000-token context window and GPT-6 Astra 1,050,000 tokens, and both return up to 128,000 output tokens per response. Claude Fable 5.1 was released on September 1, 2026 and GPT-6 Astra on September 3, 2026. Both are closed-weights models, available only through an API.
Last verified from each provider's pricing page. All sources
Side-by-side specs
| Spec | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input / 1M tokens | $10 | $10 |
| Output / 1M tokens | $50 | $50 |
| Cache read / 1M | $0.25 | $1 |
| Cache write / 1M | $12.50 | $12.50 |
| Batch input / 1M | $5 | $5 |
| Batch output / 1M | $25 | $25 |
| Long-context rates above | - | 272,000 tokens |
| Context window | 1,000,000 | 1,050,000 |
| Max output | 128,000 | 128,000 |
| Release date | ||
| Weights | Closed | Closed |
| API model id | claude-fable-5-1 | gpt-6-astra |
| AI Gateway id | anthropic/claude-fable-5.1 | openai/gpt-6-astra |
| Last verified |
Prices in USD per 1M tokens at each provider's standard first-party rate. A dash means the provider does not bill that item separately or no primary page states it.
What each costs in practice
The same three workloads every model page uses, worked from each model's standard list rates. Swap in your own token counts with the math on each model's page.
| Workload | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| One agent session1M input tokens and 100K output tokens, no caching. | $15.00 | $15.00 |
| A chat app10,000 requests a day at 2K input and 500 output tokens each. | $450.00$13,500.00 per 30-day month | $450.00$13,500.00 per 30-day month |
| The same session at a 90% cache hit90% of the input is read from the prompt cache. The one-time cache write premium is not included. | $6.23 | $6.90 |
Show the math
Claude Fable 5.1
- One agent sessionInput: 1M x $10 = $10.00Output: 0.1M x $50 = $5.00
- A chat appInput: 20M x $10 = $200.00Output: 5M x $50 = $250.00
- The same session at a 90% cache hitCached input: 0.9M x $0.25 = $0.225Uncached input: 0.1M x $10 = $1.00Output: 0.1M x $50 = $5.00
GPT-6 Astra
- One agent sessionInput: 1M x $10 = $10.00Output: 0.1M x $50 = $5.00
- A chat appInput: 20M x $10 = $200.00Output: 5M x $50 = $250.00
- The same session at a 90% cache hitCached input: 0.9M x $1 = $0.90Uncached input: 0.1M x $10 = $1.00Output: 0.1M x $50 = $5.00
Benchmarks under the same setting
Only boards that list both models under the same run setting appear here, one row per board and setting, with each score exactly as the board shows it. Scores on different boards use different scales and are never combined.
| Board and setting | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| ARC-AGI-2reasoning level: MaxOfficial leaderboard - arcprize.org | 90.0% | 95.0% |
| ARC-AGI-2reasoning level: XHighOfficial leaderboard - arcprize.org | 90.0% | 93.3% |
| ARC-AGI-2reasoning level: HighOfficial leaderboard - arcprize.org | 88.8% | 92.1% |
| Humanity's Last ExamHLE public set (2,500 questions), temperature 0.0 when configurable, o3-mini-2025-01-31 judge; score is accuracy % with 95% CI; no per-entry eval date shown, date is leaderboard read dateOfficial leaderboard - labs.scale.com | 46.50±2.00 | 54.80±1.94 |
| LMArena WebDev (Code Arena WebDev Overall)Code Arena WebDev Overall, default leaderboard view (891,922 votes, 145 models)Official leaderboard - arena.ai | 1741+9/-9 | 1777+10/-10 |
Set them up in your tools
Step-by-step guides whose official docs list Claude Fable 5.1 or GPT-6 Astra by model id.
Model pages
FAQ
How do Claude Fable 5.1 and GPT-6 Astra compare on price?
Both list the same first-party API price: $10 per 1M input tokens and $50 per 1M output tokens. For one agent session of 1M input and 100K output tokens with no caching, that is $15.00 on Claude Fable 5.1 and $15.00 on GPT-6 Astra. Prices are each provider's first-party list rates, verified October 17, 2026 and October 17, 2026.
What are the context windows of Claude Fable 5.1 and GPT-6 Astra?
Claude Fable 5.1 has a 1,000,000-token context window and GPT-6 Astra 1,050,000 tokens, and both return up to 128,000 output tokens per response.
Are Claude Fable 5.1 and GPT-6 Astra open weights?
Claude Fable 5.1 is closed-weights and is called through Anthropic's API as claude-fable-5-1. GPT-6 Astra is closed-weights and is called through OpenAI's API as gpt-6-astra.
More comparisons
Sources
Claude Fable 5.1 verified from platform.claude.com; GPT-6 Astra verified from developers.openai.com. This page is as current as the older of the two: .
- https://platform.claude.com/docs/en/about-claude/pricing
- https://developers.openai.com/api/docs/pricing
- https://platform.claude.com/docs/en/models/fable-5-1/overview
- https://platform.claude.com/docs/en/about-claude/models/overview
- https://platform.claude.com/docs/en/release-notes/overview
- https://developers.openai.com/api/docs/models/gpt-6-astra
- https://developers.openai.com/api/docs/changelog
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