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Comparison · 2 models · Updated Oct 4, 2026

Claude Fable 5 vs GPT-5.4 Pro

Claude Fable 5 comes out ahead, 65 to 60 on our weighted score, and it is the cheaper option too.

  1. Our pick

    Anthropic

    Claude Fable 5

    Released Jun 9, 2026

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

  2. OpenAI

    GPT-5.4 Pro

    Released Mar 5, 2026

    60/100
    • ECI159.1
    • Price$30.00 / $180.00
    • Context1.05M
    Full specs Remove GPT-5.4 Pro

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Claude Fable 5 is our pick

Claude Fable 5 is the better all-round choice, scoring 65/100 against GPT-5.4 Pro (60). It leads on capability and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Fable 5Capabilities Index (ECI): Claude Fable 5 162.2 · GPT-5.4 Pro 159.1
  • Lowest priceClaude Fable 5Claude Fable 5 $20.00 · GPT-5.4 Pro $67.50 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.4 ProGPT-5.4 Pro 1,050,000 · Claude Fable 5 1,000,000 tokens
  • Widest inputsClaude Fable 5Claude Fable 5: Text, Images, PDFs · GPT-5.4 Pro: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Fable 5GPT-5.4 Pro
CapabilityCapabilities Index (ECI)50%9490
Price25%00
Inputs & features15%8060
Context window10%6061
Overall100%65/10060/100
02 — Side by side

Every spec in one table

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

Claude Fable 5 vs GPT-5.4 Pro specifications side by side
SpecificationClaude Fable 5AnthropicGPT-5.4 ProOpenAI
Capability
Capabilities Index (ECI)162.2 (best)159.1
ECI rank#7 of 148 (best)#11 of 148
GPQA DiamondGraduate-level science questions85.9%94.6% (best)
FrontierMath Tiers 1–3Research-level mathematics87.0% (best)82.5%
OTIS Mock AIME 2024–2025Competition mathematics100%—
SimpleQA VerifiedShort factual questions70.7% (best)46.3%
Price per million tokens
Input$10.00 (best)$30.00
Output$50.00 (best)$180.00
Cached input$1.00—
Blended (3:1)$20.00 (best)$67.50
Long-context rateSame rateOver 272K: $60.00 / $270.00
Price sourceOfficial Anthropic APIOfficial OpenAI API
Limits
Context window1,000,000 tokens1,050,000 tokens (best)
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhigh · maxYesmedium · high · xhigh
Tool callingYesYes
Structured outputYesNo
Availability
WeightsProprietaryProprietary
API model IDclaude-fable-5gpt-5.4-pro
API providers38 (best)16
ReleasedJun 9, 2026Mar 5, 2026
Knowledge cutoffJan 31, 2026Aug 31, 2025
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.

  • Claude Fable 5$200.00
  • GPT-5.4 Pro$660.00
04 — Questions

Which should you choose?

Which is better: Claude Fable 5 or GPT-5.4 Pro?

Claude Fable 5 is the better all-round choice, scoring 65/100 against GPT-5.4 Pro (60). It leads on capability and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Fable 5 or GPT-5.4 Pro?

Claude Fable 5 is cheaper at $10.00 input / $50.00 output per million tokens (official Anthropic API price). GPT-5.4 Pro costs $30.00 input / $180.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $20.00 per million tokens for Claude Fable 5 versus $67.50 for GPT-5.4 Pro (3.4× 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-5.4 Pro 159.1 (#11 of 148). The confidence ranges of the top two overlap (159.6–166.1 vs 156.5–161.9), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.4 Pro 94.6%, Claude Fable 5 85.9%; FrontierMath Tiers 1–3 — Claude Fable 5 87.0%, GPT-5.4 Pro 82.5%; SimpleQA Verified — Claude Fable 5 70.7%, GPT-5.4 Pro 46.3%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Fable 5 and GPT-5.4 Pro 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-5.4 Pro has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Fable 5. Maximum output per response: Claude Fable 5 up to 128,000, GPT-5.4 Pro up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Fable 5 accepts text, images and PDFs; GPT-5.4 Pro accepts text and images. Claude Fable 5 handles the widest range of inputs.

Are any of these open source?

No. Claude Fable 5 and GPT-5.4 Pro are proprietary and only available through APIs and apps.

Which is newer?

Claude Fable 5 is the newest, released Jun 9, 2026. GPT-5.4 Pro came out Mar 5, 2026. Knowledge cutoff: Claude Fable 5 Jan 31, 2026, GPT-5.4 Pro Aug 31, 2025.

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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