text model comparison
Claude Fable 5.1 vs GPT-6 Astra
Claude Fable 5.1 and GPT-6 Astra are both current text models, from Anthropic and OpenAI. Both cost $10 per 1M input tokens. On Arena Text, Claude Fable 5.1 scores 1501 Elo and GPT-6 Astra 1475 Elo (Arena, measured October 8, 2026). GPT-6 Astra has the larger context window, 1,050,000 vs 1,000,000 tokens.
Data verified October 12, 2026 · Dataset 2026-10-12
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| Price per 1M input tokens | $10 | $10 |
| Price per 1M output tokens | $50 | $50 |
| Cost of 10M input and 2M output tokens | $200 | $200 |
| Arena Text | 1501 Elo (#3 of 39) (better) | 1475 Elo (#18 of 39) |
| FrontierMath Tiers 1-3 (v2) | 90.2% (#4 of 37) | 93.7% (#1 of 37) (better) |
| SimpleQA Verified | 70.8% (#5 of 34) | 75.6% (#1 of 34) (better) |
| GPQA Diamond | Not measured | 95.8% (#1 of 37) |
| Provider | Anthropic | OpenAI |
| Release date | September 1, 2026 | September 3, 2026 |
| Access | API only | API only |
| Context window | 1,000,000 tokens | 1,050,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Input | text, image | text, image |
| Output | text | text |
When to choose each
Claude Fable 5.1
Best for
- Long-horizon agentic coding where a large prompt prefix is replayed across many turns
- Work where Claude Opus 5 at higher effort has already been evaluated and fell short
Watch out for
- Base input and output pricing is unchanged from Fable 5 at $10 / $50; the saving is entirely in cache reads, so a workload with little cache reuse sees no discount
- The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates are not directly comparable across generations
- Anthropic’s launch comparisons are self-reported and were not reproduced independently here
GPT-6 Astra
Best for
- Frontier reasoning and agentic evaluations where deep-context retrieval accuracy is the binding constraint
- Workloads that can be kept under the long-context threshold, where the effective rate stays at $10 / $50
Watch out for
- Long-context billing is a cliff, not a taper: a request over the long-context threshold is rebilled in full at $20 per million input and $75 per million output, so a prompt that crosses it costs roughly double
- GPT-6 Astra is the first publicly released model OpenAI classifies as crossing the Critical cybersecurity threshold under its own Preparedness Framework, which carries additional deployment safeguards
- Vendor-reported benchmark figures come from OpenAI’s own launch material and its own harness; they are not independently reproduced here
Claude Fable 5.1 vs GPT-6 Astra FAQ
Which is cheaper, Claude Fable 5.1 or GPT-6 Astra?
Both cost $10 per 1M input tokens. For 10M input and 2M output tokens, Claude Fable 5.1 costs $200 and GPT-6 Astra $200 at standard rates.
Which scores higher on independent benchmarks, Claude Fable 5.1 or GPT-6 Astra?
Claude Fable 5.1 leads on Arena Text, 1501 Elo to 1475 Elo; GPT-6 Astra leads on FrontierMath Tiers 1-3 (v2), 93.7% to 90.2%; GPT-6 Astra leads on SimpleQA Verified, 75.6% to 70.8%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Fable 5.1 or GPT-6 Astra?
GPT-6 Astra has the larger context window, 1,050,000 vs 1,000,000 tokens.
Related comparisons
Production evaluation
Choosing between Claude Fable 5.1 and GPT-6 Astra?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty