AI model comparison
GPT-6 Astra vs Claude Fable 5.1
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
OpenAI
GPT-6 Astra
GPT-6 Astra is OpenAI's flagship model for demanding end-to-end work.
- Input / 1M
- $10
- Output / 1M
- $50
- Context
- 1.05M
Anthropic
Claude Fable 5.1
Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual
- Input / 1M
- $10
- Output / 1M
- $50
- Context
- 1M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Tie
Same price for a typical chat
Higher intelligence score
Claude Fable 5.1
53.4 vs 52.7 on Artificial Analysis
Larger context window
GPT-6 Astra
1.05M vs 1M tokens
Newer release
GPT-6 Astra
Released September 4, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-6 Astra52.7Claude Fable 5.153.4Coding index
GPT-6 Astra76.9Claude Fable 5.181.6Agentic index
GPT-6 Astra51Claude Fable 5.157.9Pricing
GPT-6 Astra vs Claude Fable 5.1 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-6 Astra | Claude Fable 5.1 |
|---|---|---|
| Input tokensPer 1M tokens | $10 | $10 |
| Output tokensPer 1M tokens | $50 | $50 |
| Cached input (read)Per 1M tokens | $1 | $0.25 |
| Cache writePer 1M tokens | $12.50 | $12.50 |
| Long-context pricingPer 1M tokens, for very long prompts | $20 in / $75 out above 272K | Same rate at any length |
| Web searchPer request | $0.01 | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
GPT-6 Astra$45Claude Fable 5.1$45Coding task
30K in, 4K out
GPT-6 Astra$500$230 cachedClaude Fable 5.1$500$207.50 cachedLong document summary
150K in, 2K out
GPT-6 Astra$1600$250 cachedClaude Fable 5.1$1600$137.50 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | GPT-6 Astra | Claude Fable 5.1 |
|---|---|---|
| Context window | 1.05M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Input types | File, Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, Extra high, High, Medium, Low | Max, Extra high, High, Medium, Low |
| Default reasoning effort | Medium | High |
| Release date | September 4, 2026 | September 1, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-6 Astra | Claude Fable 5.1 |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Not supported |
| Stop sequences | Not supported | Supported |
| Deterministic seed | Supported | Not supported |
| Verbosity control | Supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
GPT-6 AstraView full model details- GPT-6 Astra vs Claude Opus 5.5
- GPT-6 Astra vs Claude Sonnet 5.5
- GPT-6 Astra vs GPT-6.1 Sol
- GPT-6 Astra vs Claude Opus 5
- GPT-6 Astra vs Claude Fable 5
- GPT-6 Astra vs Muse Spark 1.3
- GPT-6 Astra vs GPT-6 Sol
- GPT-6 Astra vs GPT-5.6 Sol
- GPT-6 Astra vs Grok 4.7
- GPT-6 Astra vs GLM 5.3
- GPT-6 Astra vs Kimi K3
- GPT-6 Astra vs GLM 5.3 Flash
- GPT-6 Astra vs Gemini 3.8 Flash
- GPT-6 Astra vs DeepSeek V4.1 Flash
- GPT-6 Astra vs MiMo-V2.6-Flash
- GPT-6 Astra vs Hy4 preview
- GPT-6 Astra vs GPT-6 Luna
- GPT-6 Astra vs DeepSeek V4 Flash 0731
- GPT-6 Astra vs Gemini 3.1 Pro Preview
Claude Fable 5.1View full model details- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Fable 5.1 vs Claude Sonnet 5.5
- Claude Fable 5.1 vs GPT-6.1 Sol
- Claude Fable 5.1 vs Claude Opus 5
- Claude Fable 5.1 vs Claude Fable 5
- Claude Fable 5.1 vs Muse Spark 1.3
- Claude Fable 5.1 vs GPT-6 Sol
- Claude Fable 5.1 vs GPT-5.6 Sol
- Claude Fable 5.1 vs Kimi K3
- Claude Fable 5.1 vs GLM 5.3 Flash
- Claude Fable 5.1 vs Claude Opus 4.8
- Claude Fable 5.1 vs DeepSeek V4.1 Flash
- Claude Fable 5.1 vs GPT-6 Luna
- Claude Fable 5.1 vs MiMo-V2.6-Flash
- Claude Fable 5.1 vs DeepSeek V4 Flash 0731
- Claude Fable 5.1 vs Hy4 preview
Our take
Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index (53.4 vs 52.7). GPT-6 Astra has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is GPT-6 Astra or Claude Fable 5.1 cheaper?
GPT-6 Astra and Claude Fable 5.1 cost the same for a typical chat (2K input tokens and 500 output tokens). GPT-6 Astra costs $10 per 1M input tokens and $50 per 1M output tokens, and Claude Fable 5.1 costs $10 per 1M input tokens and $50 per 1M output tokens.
Which has a bigger context window, GPT-6 Astra or Claude Fable 5.1?
GPT-6 Astra supports up to 1.05M tokens of context, compared with 1M for Claude Fable 5.1.
Is GPT-6 Astra smarter than Claude Fable 5.1?
On the Artificial Analysis Intelligence Index, GPT-6 Astra scores 52.7 and Claude Fable 5.1 scores 53.4, putting Claude Fable 5.1 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use GPT-6 Astra and Claude Fable 5.1 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GPT-6 Astra and Claude Fable 5.1 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to GPT-6 Astra and Claude Fable 5.1 at the same time. Compare the answers side by side and keep the best one.