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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.6 Sol vs Claude Fable 5

Too close to call on our weighted score (GPT-5.6 Sol 66, Claude Fable 5 65). The right pick depends on what you value most.

  1. OpenAI

    GPT-5.6 Sol

    Released Jul 9, 2026

    66/100
    • ECI161.8
    • Price$4.00 / $20.00
    • Context1.05M
    Full specs Remove GPT-5.6 Sol

  2. Anthropic

    Claude Fable 5

    Released Jun 9, 2026

    65/100
    • ECI162.2
    • Price$10.00 / $50.00
    • Context1M
    Full specs Remove Claude Fable 5

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01 — Verdict

Too close to call

It is close. Our weighted score puts them within 2 points (GPT-5.6 Sol 66/100, Claude Fable 5 65/100), so choose by what matters most for your work: Claude Fable 5 for raw capability, GPT-5.6 Sol on price and GPT-5.6 Sol for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Fable 5Capabilities Index (ECI): Claude Fable 5 162.2 · GPT-5.6 Sol 161.8
  • Lowest priceGPT-5.6 SolGPT-5.6 Sol $8.00 · Claude Fable 5 $20.00 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.6 SolGPT-5.6 Sol 1,050,000 · Claude Fable 5 1,000,000 tokens
  • Widest inputsSame inputsGPT-5.6 Sol: Text, Images, PDFs · Claude Fable 5: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.6 SolClaude Fable 5
CapabilityCapabilities Index (ECI)50%9394
Price25%70
Inputs & features15%8080
Context window10%6160
Overall100%66/10065/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-5.6 Sol vs Claude Fable 5 specifications side by side
SpecificationGPT-5.6 SolOpenAIClaude Fable 5Anthropic
Capability
Capabilities Index (ECI)161.8162.2 (best)
ECI rank#8 of 148#7 of 148 (best)
GPQA DiamondGraduate-level science questions93.5% (best)85.9%
FrontierMath Tiers 1–3Research-level mathematics89.1% (best)87.0%
OTIS Mock AIME 2024–2025Competition mathematics100%100%
SimpleQA VerifiedShort factual questions69.7%70.7% (best)
Price per million tokens
Input$4.00 (best)$10.00
Output$20.00 (best)$50.00
Cached input$0.40 (best)$1.00
Blended (3:1)$8.00 (best)$20.00
Long-context rateOver 272K: $8.00 / $30.00Same rate
Price sourceOfficial OpenAI APIOfficial Anthropic API
Limits
Context window1,050,000 tokens (best)1,000,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhigh · maxYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5.6-solclaude-fable-5
API providers40 (best)38
ReleasedJul 9, 2026Jun 9, 2026
Knowledge cutoffFeb 16, 2026Jan 31, 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-5.6 Sol$80.00
  • Claude Fable 5$200.00
04 — Questions

Which should you choose?

Which is better: GPT-5.6 Sol or Claude Fable 5?

It is close. Our weighted score puts them within 2 points (GPT-5.6 Sol 66/100, Claude Fable 5 65/100), so choose by what matters most for your work: Claude Fable 5 for raw capability, GPT-5.6 Sol on price and GPT-5.6 Sol for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.6 Sol or Claude Fable 5?

GPT-5.6 Sol is cheaper at $4.00 input / $20.00 output per million tokens (official OpenAI API price). Claude Fable 5 costs $10.00 input / $50.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $8.00 per million tokens for GPT-5.6 Sol versus $20.00 for Claude Fable 5 (2.5× as much).

Which scores higher on benchmarks?

Claude Fable 5 scores higher on the Capabilities Index (ECI): Claude Fable 5 162.2 (#7 of 148) and GPT-5.6 Sol 161.8 (#8 of 148). The confidence ranges of the top two overlap (159.6–166.1 vs 159.3–165.3), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.6 Sol 93.5%, Claude Fable 5 85.9%; FrontierMath Tiers 1–3 — GPT-5.6 Sol 89.1%, Claude Fable 5 87.0%; OTIS Mock AIME 2024–2025 — GPT-5.6 Sol 100%, Claude Fable 5 100%; SimpleQA Verified — Claude Fable 5 70.7%, GPT-5.6 Sol 69.7%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.6 Sol and Claude Fable 5 yet, so there is no like-for-like coding score. On overall capability, Claude Fable 5 leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.6 Sol has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Fable 5. Maximum output per response: GPT-5.6 Sol up to 128,000, Claude Fable 5 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.6 Sol accepts text, images and PDFs; Claude Fable 5 accepts text, images and PDFs. They handle the same number of input types.

Are any of these open source?

No. GPT-5.6 Sol and Claude Fable 5 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.6 Sol is the newest, released Jul 9, 2026. Claude Fable 5 came out Jun 9, 2026. Knowledge cutoff: GPT-5.6 Sol Feb 16, 2026, Claude Fable 5 Jan 31, 2026.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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