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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.4 Pro vs Claude Fable 5

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

  1. 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
  2. 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

  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 5GPT-5.4 Pro: Text, Images · Claude Fable 5: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.4 ProClaude Fable 5
CapabilityCapabilities Index (ECI)50%9094
Price25%00
Inputs & features15%6080
Context window10%6160
Overall100%60/10065/100
02 — Side by side

Every spec in one table

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

GPT-5.4 Pro vs Claude Fable 5 specifications side by side
SpecificationGPT-5.4 ProOpenAIClaude Fable 5Anthropic
Capability
Capabilities Index (ECI)159.1162.2 (best)
ECI rank#11 of 148#7 of 148 (best)
GPQA DiamondGraduate-level science questions94.6% (best)85.9%
FrontierMath Tiers 1–3Research-level mathematics82.5%87.0% (best)
OTIS Mock AIME 2024–2025Competition mathematics—100%
SimpleQA VerifiedShort factual questions46.3%70.7% (best)
Price per million tokens
Input$30.00$10.00 (best)
Output$180.00$50.00 (best)
Cached input—$1.00
Blended (3:1)$67.50$20.00 (best)
Long-context rateOver 272K: $60.00 / $270.00Same 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
PDFsNoYes
AudioNoNo
VideoNoNo
ReasoningYesmedium · high · xhighYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputNoYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5.4-proclaude-fable-5
API providers1638 (best)
ReleasedMar 5, 2026Jun 9, 2026
Knowledge cutoffAug 31, 2025Jan 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-5.4 Pro$660.00
  • Claude Fable 5$200.00
04 — Questions

Which should you choose?

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

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, GPT-5.4 Pro or Claude Fable 5?

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 GPT-5.4 Pro 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-5.4 Pro has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Fable 5. Maximum output per response: GPT-5.4 Pro up to 128,000, Claude Fable 5 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

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

Are any of these open source?

No. GPT-5.4 Pro and Claude Fable 5 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: GPT-5.4 Pro Aug 31, 2025, 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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