text model comparison
Claude Fable 5.1 vs GPT-5.5
Claude Fable 5.1 and GPT-5.5 are both current text models, from Anthropic and OpenAI. GPT-5.5 is 50% cheaper per 1M input tokens than Claude Fable 5.1, $5 vs $10. On Arena Text, Claude Fable 5.1 scores 1501 Elo and GPT-5.5 1482 Elo (Arena, measured October 8, 2026). GPT-5.5 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-5.5 |
|---|---|---|
| Price per 1M input tokens | $10 | $5 (better) |
| Price per 1M output tokens | $50 | $30 (better) |
| Cost of 10M input and 2M output tokens | $200 | $110 (better) |
| Arena Text | 1501 Elo (#3 of 39) (better) | 1482 Elo (#13 of 39) |
| FrontierMath Tiers 1-3 (v2) | 90.2% (#4 of 37) (better) | 85.3% (#11 of 37) |
| SimpleQA Verified | 70.8% (#5 of 34) (better) | 63% (#13 of 34) |
| GPQA Diamond | Not measured | 90.7% (#21 of 37) |
| LiveBench Overall | Not measured | 79.91 points (#1 of 5) |
| Provider | Anthropic | OpenAI |
| Release date | September 1, 2026 | April 23, 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 |
Scores:Arena · 2026-10-12Epoch AI · 2026-10-12LiveBench · 2026-06-25
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-5.5
Best for
- High-capability API evaluations with long context
Watch out for
- Prompts above the provider long-context threshold use higher token rates; validate the selected reasoning effort against production cost
Claude Fable 5.1 vs GPT-5.5 FAQ
Which is cheaper, Claude Fable 5.1 or GPT-5.5?
GPT-5.5 is 50% cheaper per 1M input tokens than Claude Fable 5.1, $5 vs $10. For 10M input and 2M output tokens, Claude Fable 5.1 costs $200 and GPT-5.5 $110 at standard rates.
Which scores higher on independent benchmarks, Claude Fable 5.1 or GPT-5.5?
Claude Fable 5.1 leads on Arena Text, 1501 Elo to 1482 Elo; Claude Fable 5.1 leads on FrontierMath Tiers 1-3 (v2), 90.2% to 85.3%; Claude Fable 5.1 leads on SimpleQA Verified, 70.8% to 63%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Fable 5.1 or GPT-5.5?
GPT-5.5 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-5.5?
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