AI Model Picker comparison
Claude Fable 5.1 vs GPT-5.6 Sol
Both products reached the final shortlist for the same buyer profile — Frontier Reasoning — in the AI Model Picker. Your answers favor maximum capability for hard reasoning, coding, and agentic work — cost is secondary to getting the task done.
Anthropic
Claude Fable 5.1
AA index #1 · From $10 / $50 per 1M tokens; cache reads $0.25 per 1M · Not independently rated
OpenAI
GPT-5.6 Sol
OpenAI frontier · From $4 / $20 per 1M tokens (short context; promo through Nov 21 2026); $8 / $30 long context · Not independently rated
| What differs | Claude Fable 5.1 | GPT-5.6 Sol |
|---|---|---|
| Vendor | Anthropic | OpenAI |
| Positioning | AA index #1 | OpenAI frontier |
| Price positioning | From $10 / $50 per 1M tokens; cache reads $0.25 per 1M | From $4 / $20 per 1M tokens (short context; promo through Nov 21 2026); $8 / $30 long context |
| Editorial rating | Not independently rated | Not independently rated |
| Best for | Hardest reasoning and frontier agent work where quality is the constraint. | Complex reasoning and agentic workflows when cost is not the primary constraint. |
Intelligence comparison
What actually differs
Structured comparison from canonical product intelligence — verification status and recent pricing changes included.
| Criterion | Claude Fable 5.1 | GPT-5.6 Sol |
|---|---|---|
| Model | ||
| Context window | 1,000,000 tokens Partially verifiedSource: Official source | 1,050,000 tokens Partially verifiedSource: Official source |
| Provider | Anthropic Partially verifiedSource: Official source | OpenAI Partially verifiedSource: Official source |
| Pricing | ||
| Input price | $10.00/1M tokens Partially verifiedSource: Official source | $4.00/1M tokens Partially verifiedSource: Official source |
| Output price | $50.00/1M tokens Partially verifiedSource: Official source | $20.00/1M tokens Partially verifiedSource: Official source |
| Trust | ||
| Data freshness | Partially verified Partially verifiedSource: Official source | Partially verified Partially verifiedSource: Official source |
Model
Context window
Claude Fable 5.1
1,000,000 tokens
GPT-5.6 Sol
1,050,000 tokens
Provider
Claude Fable 5.1
Anthropic
GPT-5.6 Sol
OpenAI
Pricing
Input price
Claude Fable 5.1
$10.00/1M tokens
GPT-5.6 Sol
$4.00/1M tokens
Output price
Claude Fable 5.1
$50.00/1M tokens
GPT-5.6 Sol
$20.00/1M tokens
Trust
Data freshness
Claude Fable 5.1
Partially verified
GPT-5.6 Sol
Partially verified
Features
What each one leads with
The standout capabilities recorded for each product in the recommendation data.
Claude Fable 5.1
- 1M context (verified on profile)
- 128K max output
- Adaptive thinking always on
GPT-5.6 Sol
- 1.05M context (verified on profile)
- Reasoning effort levels
- Image input modality
Trade-offs
Pros and cons, side by side
The strengths and the catches the decision tool already weighs for this buyer profile.
Claude Fable 5.1
Pros
- Topped LiveBench and the AA Intelligence Index at launch
- Cache reads cut 75% versus Fable 5
Cons
- Same $10/$50 list as Fable 5 — quality, not price, is the change
- Closed weights — no self-hosting
GPT-5.6 Sol
Pros
- Flagship OpenAI tier in the catalog
- Profile links to comparisons vs Terra and Luna
Cons
- 25× Luna input price for routine volume work
- Closed weights — no self-hosting
The verdict
Who should pick which
Assembled from the same recommendation fields the tool scores on — not a universal winner.
Both products are finalists for the same buyer profile, so this is a fit decision rather than a category decision. Claude Fable 5.1 is aimed at hardest reasoning and frontier agent work where quality is the constraint. GPT-5.6 Sol is aimed at complex reasoning and agentic workflows when cost is not the primary constraint. Neither product has an independently verified rating here, so use the fit criteria and current product evidence rather than a synthetic score.
Choose Claude Fable 5.1 if…
Hardest reasoning and frontier agent work where quality is the constraint.
Watch out for
Same $10/$50 list as Fable 5 — quality, not price, is the change
From $10 / $50 per 1M tokens; cache reads $0.25 per 1M
Choose GPT-5.6 Sol if…
Complex reasoning and agentic workflows when cost is not the primary constraint.
Watch out for
25× Luna input price for routine volume work
From $4 / $20 per 1M tokens (short context; promo through Nov 21 2026); $8 / $30 long context
Common questions
Claude Fable 5.1 vs GPT-5.6 Sol
Answered from the verified figures on this page rather than general guidance.
Is Claude Fable 5.1 or GPT-5.6 Sol cheaper?
Claude Fable 5.1 is positioned as "From $10 / $50 per 1M tokens; cache reads $0.25 per 1M" and GPT-5.6 Sol as "From $4 / $20 per 1M tokens (short context; promo through Nov 21 2026); $8 / $30 long context". These are positioning labels, not verified prices, so treat the difference as a prompt to check each vendor's current plans rather than a confirmed price gap.
Which is rated higher, Claude Fable 5.1 or GPT-5.6 Sol?
Neither has an independently verified rating in this comparison. The catalog uses fit guidance and price positioning instead; confirm external reviews and current product evidence before deciding.
Should I choose Claude Fable 5.1 or GPT-5.6 Sol?
Choose Claude Fable 5.1 if your situation matches its "best for" line: hardest reasoning and frontier agent work where quality is the constraint. Choose GPT-5.6 Sol if yours matches: complex reasoning and agentic workflows when cost is not the primary constraint. Both were shortlisted for the same buyer profile, so the closer match — not the badge or the rating — is the deciding signal.
What is the catch with Claude Fable 5.1 and GPT-5.6 Sol?
Claude Fable 5.1: Same $10/$50 list as Fable 5 — quality, not price, is the change. Closed weights — no self-hosting. GPT-5.6 Sol: 25× Luna input price for routine volume work. Closed weights — no self-hosting.
A head-to-head answers one question: of the two finalists for this buyer profile, which fits your situation. If neither “best for” line matches, run the full tool — its other profiles exist for different buyers.