Claude Fable 5.1 vs GPT-5.6 Sol: pricing and benchmarks
GPT-5.6 Sol is 60% cheaper on input tokens ($4.00 vs $10.00 per 1M). GPT-5.6 Sol is 60% cheaper on output tokens ($20.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), GPT-5.6 Sol costs $2,200 a month versus $5,500 for Claude Fable 5.1, 60% less. Roughly tied. Claude Fable 5.1 scores 164.5 and GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index, and their confidence intervals overlap.
Prices verified September 14, 2026.
Which should you choose?
Roughly tied. Claude Fable 5.1 scores 164.5 and GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index, and their confidence intervals overlap.
About even on FrontierMath (Tiers 1–3): 90.2% for Claude Fable 5.1 and 89.1% for GPT-5.6 Sol.
GPT-5.6 Sol costs $8.00 per 1M tokens (3:1 input-to-output mix) vs $20.00 for Claude Fable 5.1, 60% less.
GPT-5.6 Sol delivers statistically similar overall capability for 60% less.
Pricing and specs
| Claude Fable 5.1 | GPT-5.6 Sol | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| API model ID | claude-fable-5-1 | gpt-5.6-sol |
| Input / 1M tokens | $10.00 | $4.00 |
| Cached input / 1M tokens | $0.25 | $0.40 |
| Output / 1M tokens | $50.00 | $20.00 |
| Long-context rates | — | $8.00 in / $30.00 out on long-context requests |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 128K tokens |
| Batch discount | 50% off | 50% off |
Benchmarks
| Claude Fable 5.1 | GPT-5.6 Sol | |
|---|---|---|
| Epoch Capabilities Index | 164.5 | 161.8 |
| GPQA Diamond· Science reasoning | — | 91.3% |
| FrontierMath (Tiers 1–3)· Advanced math | 90.2% | 89.1% |
| SimpleQA Verified· Factual accuracy | 70.8% | 69.7% |
| ARC-AGI-2· Abstract reasoning | 90.0% | 92.5% |
| DeepSWE· Coding | — | 72.7% |
| APEX-Agents· Agentic work | 47.4% | 40.0% |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Claude Fable 5.1 | GPT-5.6 Sol | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $3,500 | $1,400 | GPT-5.6 Sol 60% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $5,500 | $2,200 | GPT-5.6 Sol 60% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $2,270 | $992.00 | GPT-5.6 Sol 56% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Claude Fable 5.1 vs GPT-5.6 Sol cost calculator
- $2,200/mo$0.04 / request
- Claude Fable 5.1Anthropic$5,500/mo$0.11 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Claude Fable 5.1 pricing notes
Anthropic’s model for demanding reasoning and long-horizon agentic work.
- Cache hits cost 2.5% of the base input price, versus 10% on other Claude models.
- Cache writes cost $12.50 (5-minute cache) or $20 (1-hour cache) per 1M tokens.
- Uses Anthropic’s newer tokenizer, which produces roughly 30% more tokens for the same text.
- US-only inference (inference_geo: "us") costs 1.1x.
GPT-5.6 Sol pricing notes
OpenAI’s flagship GPT-5.6 model for complex professional work.
- Promotional pricing, available at least through November 21, 2026.
- Cache writes are billed at $5 per 1M tokens.
- Regional (data residency) endpoints add a 10% uplift.
Frequently asked questions
- Is Claude Fable 5.1 cheaper than GPT-5.6 Sol?
- GPT-5.6 Sol is 60% cheaper on input tokens ($4.00 vs $10.00 per 1M). GPT-5.6 Sol is 60% cheaper on output tokens ($20.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), GPT-5.6 Sol costs $2,200 a month versus $5,500 for Claude Fable 5.1, 60% less.
- Which is more capable, Claude Fable 5.1 or GPT-5.6 Sol?
- Roughly tied. Claude Fable 5.1 scores 164.5 and GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index, and their confidence intervals overlap.
- How much does Claude Fable 5.1 cost per 1M tokens?
- Claude Fable 5.1 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens, and $0.25 per 1M cached input tokens on Anthropic’s standard tier.
- How much does GPT-5.6 Sol cost per 1M tokens?
- GPT-5.6 Sol costs $4.00 per 1M input tokens and $20.00 per 1M output tokens, and $0.40 per 1M cached input tokens on OpenAI’s standard tier.
- Which has the larger context window, Claude Fable 5.1 or GPT-5.6 Sol?
- GPT-5.6 Sol has the larger context window: 1.05M tokens versus 1M for Claude Fable 5.1.