GPT-6.1 Sol vs Claude Fable 5.1
GPT-6.1 Sol and Claude Fable 5.1 are within three points on the Models at Work leaderboard, which we treat as a tie (82 vs 80). GPT-6.1 Sol is about 5.0× cheaper per blended million tokens ($4 vs $20). On Artificial Analysis' independent Intelligence Index, Claude Fable 5.1 leads 53 to 52.
| GPT-6.1 Sol · OpenAI | Claude Fable 5.1 · Anthropic | |
|---|---|---|
| Leaderboard rank | #5 | #6 |
| Score (0–100) | 82 | 80 |
| Tier | Workhorse | Frontier |
| Price per 1M tokens | $2 in · $10 out | $10 in · $50 out |
| Context window | 1M | 1M |
| Open weights | No | No |
| Artificial Analysis Intelligence Index | 52 | 53 |
| Humanity's Sixth Sense (Scale) | 46.6 | — |
| Arena text score | — | 1501 |
| Humanity's Last Exam, Diamond (Scale) | — | 51.3 |
| Best for | OpenAI-standardised teams, Agents API and Decisions API, Cost-controlled reasoning | Long-horizon agents, Problems Opus fails on, Demanding reasoning |
Choose GPT-6.1 Sol if…
- you need openai-standardised teams
- you need agents api and decisions api
- you need cost-controlled reasoning
Near-Astra intelligence at a fifth of the price, which is OpenAI's own line and, for once, the index agrees.
Choose Claude Fable 5.1 if…
- you need long-horizon agents
- you need problems opus fails on
- you need demanding reasoning
The specialist: Anthropic's own docs say to reach for it when Opus 5.5 at high effort still falls short, and the price says the same.
Caveats: Ten dollars per million input is the highest in this table alongside Astra.
What practitioners say
GPT-6.1 Sol: The launch thread's title did the arguing: 'near-Astra for a fifth of the price' drew 955 comments, most of them about routing.
Questions people ask
Which is better, GPT-6.1 Sol or Claude Fable 5.1?
GPT-6.1 Sol and Claude Fable 5.1 are within three points on the Models at Work leaderboard, which we treat as a tie (82 vs 80). GPT-6.1 Sol is about 5.0× cheaper per blended million tokens ($4 vs $20). On Artificial Analysis' independent Intelligence Index, Claude Fable 5.1 leads 53 to 52.
When should I choose GPT-6.1 Sol over Claude Fable 5.1?
Choose GPT-6.1 Sol for openai-standardised teams, agents api and decisions api, cost-controlled reasoning. Near-Astra intelligence at a fifth of the price, which is OpenAI's own line and, for once, the index agrees.
When should I choose Claude Fable 5.1 over GPT-6.1 Sol?
Choose Claude Fable 5.1 for long-horizon agents, problems opus fails on, demanding reasoning. The specialist: Anthropic's own docs say to reach for it when Opus 5.5 at high effort still falls short, and the price says the same.
Which is cheaper, GPT-6.1 Sol or Claude Fable 5.1?
GPT-6.1 Sol costs $2 per million input tokens and $10 per million output tokens on OpenAI's list price (OpenAI API pricing, read Oct 10, 2026). Claude Fable 5.1 costs $10 per million input tokens and $50 per million output tokens on Anthropic's list price (Claude pricing, read Oct 10, 2026).
Scores come from the Models at Work leaderboard: Score is 0 to 100: 50% independent evals normalised within this table, 20% price-performance, 15% practitioner sentiment from Signals and community threads, 15% operational fit (context, speed, availability, open weights). Models within three points are a tie in practice. Vendor-published figures are labelled as such and never counted as independent. Prices are vendor list prices where published; blended figures assume three input tokens per output token.