GPT-6 Astra vs DeepSeek V4.1 Flash 1017 vs Claude Fable 5.1
DeepSeek V4.1 Flash 1017 comes out ahead, 79 to 68 and 66 on our weighted score, and it is the cheaper option too.
OpenAIGPT-6 Astra
68/100- ECI169.1
- Price$10.00 / $50.00
- Context1.05M
- Our pick
DeepSeekDeepSeek V4.1 Flash 1017
79/100- ECI158.8
- Price$0.15 / $0.60
- Context1M
AnthropicClaude Fable 5.1
66/100- ECI166.4
- Price$10.00 / $50.00
- Context1M
DeepSeek V4.1 Flash 1017 is our pick
DeepSeek V4.1 Flash 1017 is the better all-round choice, scoring 79/100 against GPT-6 Astra (68) and Claude Fable 5.1 (66). It leads on price. GPT-6 Astra wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-6 AstraCapabilities Index (ECI): GPT-6 Astra 169.1 · Claude Fable 5.1 166.4 · DeepSeek V4.1 Flash 1017 158.8
- Lowest priceDeepSeek V4.1 Flash 1017DeepSeek V4.1 Flash 1017 $0.263 · GPT-6 Astra $20.00 · Claude Fable 5.1 $20.00 per 1M tokens (3:1 blend)
- Longest contextGPT-6 AstraGPT-6 Astra 1,050,000 · DeepSeek V4.1 Flash 1017 1,000,000 · Claude Fable 5.1 1,000,000 tokens
- Widest inputsGPT-6 Astra and Claude Fable 5.1GPT-6 Astra: Text, Images, PDFs · DeepSeek V4.1 Flash 1017: Text, Images · Claude Fable 5.1: Text, Images, PDFs
- Self-hostingDeepSeek V4.1 Flash 1017Publishes downloadable weights (MIT)
| Measure | Weight | GPT-6 Astra | DeepSeek V4.1 Flash 1017 | Claude Fable 5.1 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 100 | 87 | 97 |
| Price | 25% | 0 | 74 | 0 |
| Inputs & features | 15% | 80 | 70 | 80 |
| Context window | 10% | 61 | 60 | 60 |
| Overall | 100% | 68/100 | 79/100 | 66/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-6 AstraOpenAI | DeepSeek V4.1 Flash 1017DeepSeek | Claude Fable 5.1Anthropic |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 169.1 (best) | 158.8 | 166.4 |
| ECI rank | #1 of 165 (best) | #19 of 165 | #6 of 165 |
| GPQA DiamondGraduate-level science questions | 95.8% (best) | 93.2% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 93.7% (best) | 71.2% | 90.2% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% (best) | 99.4% | 100% (best) |
| SimpleQA VerifiedShort factual questions | 75.6% (best) | 42.5% | 70.8% |
| Price per million tokens | |||
| Input | $10.00 | $0.15 (best) | $10.00 |
| Output | $50.00 | $0.60 (best) | $50.00 |
| Cached input | $1.00 | $0.003 (best) | $0.25 |
| Blended (3:1) | $20.00 | $0.263 (best) | $20.00 |
| Long-context rate | Over 272K: $20.00 / $75.00 | Same rate | Same rate |
| Price source | Official OpenAI API | Official DeepSeek API | Official Anthropic API |
| Limits | |||
| Context window | 1,050,000 tokens (best) | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 384,000 tokens (best) | 128,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | No | Yes |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · high · max | Yeslow · medium · high · xhigh · max |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | OpenMIT | Proprietary |
| API model ID | gpt-6-astra | deepseek-flash | claude-fable-5-1 |
| API providers | 37 | 40 (best) | 37 |
| Released | Sep 4, 2026 | Oct 17, 2026 | Sep 1, 2026 |
| Knowledge cutoff | Apr 30, 2026 | May 2025 | Jun 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-6 Astra$200.00
- DeepSeek V4.1 Flash 1017$2.70
- Claude Fable 5.1$200.00
Which should you choose?
Which is better: GPT-6 Astra, DeepSeek V4.1 Flash 1017 or Claude Fable 5.1?
DeepSeek V4.1 Flash 1017 is the better all-round choice, scoring 79/100 against GPT-6 Astra (68) and Claude Fable 5.1 (66). It leads on price. GPT-6 Astra wins on capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-6 Astra, DeepSeek V4.1 Flash 1017 or Claude Fable 5.1?
DeepSeek V4.1 Flash 1017 is cheaper at $0.15 input / $0.60 output per million tokens (official DeepSeek API price). GPT-6 Astra costs $10.00 input / $50.00 output per million tokens (official OpenAI API price); Claude Fable 5.1 costs $10.00 input / $50.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $0.263 per million tokens for DeepSeek V4.1 Flash 1017 versus $20.00 for GPT-6 Astra (76× as much) and $20.00 for Claude Fable 5.1 (76× as much).
Which scores higher on benchmarks?
GPT-6 Astra scores higher on the Capabilities Index (ECI): GPT-6 Astra 169.1 (#1 of 165), Claude Fable 5.1 166.4 (#6 of 165) and DeepSeek V4.1 Flash 1017 158.8 (#19 of 165). The confidence ranges of the top two overlap (165.9–174.3 vs 163.6–170.8), so treat the gap as small. On individual benchmarks: FrontierMath Tiers 1–3 — GPT-6 Astra 93.7%, Claude Fable 5.1 90.2%, DeepSeek V4.1 Flash 1017 71.2%; OTIS Mock AIME 2024–2025 — GPT-6 Astra 100%, Claude Fable 5.1 100%, DeepSeek V4.1 Flash 1017 99.4%; SimpleQA Verified — GPT-6 Astra 75.6%, Claude Fable 5.1 70.8%, DeepSeek V4.1 Flash 1017 42.5%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-6 Astra, DeepSeek V4.1 Flash 1017 and Claude Fable 5.1 yet, so there is no like-for-like coding score. On overall capability, GPT-6 Astra leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
GPT-6 Astra has the largest context window at 1,050,000 tokens, against 1,000,000 for DeepSeek V4.1 Flash 1017 and 1,000,000 for Claude Fable 5.1. Maximum output per response: GPT-6 Astra up to 128,000, DeepSeek V4.1 Flash 1017 up to 384,000, Claude Fable 5.1 up to 128,000 tokens.
Which can read images, PDFs, audio or video?
GPT-6 Astra accepts text, images and PDFs; DeepSeek V4.1 Flash 1017 accepts text and images; Claude Fable 5.1 accepts text, images and PDFs. GPT-6 Astra handles the widest range of inputs.
Are any of these open source?
DeepSeek V4.1 Flash 1017 publishes its weights (MIT) and can be self-hosted; GPT-6 Astra and Claude Fable 5.1 is proprietary.
Which is newer?
DeepSeek V4.1 Flash 1017 is the newest, released Oct 17, 2026. GPT-6 Astra came out Sep 4, 2026; Claude Fable 5.1 came out Sep 1, 2026. Knowledge cutoff: GPT-6 Astra Apr 30, 2026, DeepSeek V4.1 Flash 1017 May 2025, Claude Fable 5.1 Jun 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
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