ZMIME
Comparison · 3 models · Updated Oct 4, 2026

GPT-5.4 Pro vs GPT-5.2 Pro vs Claude Fable 5

Claude Fable 5 comes out ahead, 65 to 60 and 56 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
  2. OpenAI

    GPT-5.2 Pro

    Released Dec 11, 2025

    56/100
    • ECI155.4
    • Price$21.00 / $168.00
    • Context400K
  3. Our pick

    Anthropic

    Claude Fable 5

    Released Jun 9, 2026

    65/100
    • ECI162.2
    • Price$10.00 / $50.00
    • Context1M
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) and GPT-5.2 Pro (56). 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 · GPT-5.2 Pro 155.4
  • Lowest priceClaude Fable 5Claude Fable 5 $20.00 · GPT-5.2 Pro $57.75 · 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 · GPT-5.2 Pro 400,000 tokens
  • Widest inputsClaude Fable 5GPT-5.4 Pro: Text, Images · GPT-5.2 Pro: Text, Images · Claude Fable 5: Text, Images, PDFs
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightGPT-5.4 ProGPT-5.2 ProClaude Fable 5
CapabilityCapabilities Index (ECI)50%908594
Price25%000
Inputs & features15%606080
Context window10%614460
Overall100%60/10056/10065/100
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 GPT-5.2 Pro vs Claude Fable 5 specifications side by side
SpecificationGPT-5.4 ProOpenAIGPT-5.2 ProOpenAIClaude Fable 5Anthropic
Capability
Capabilities Index (ECI)159.1155.4162.2 (best)
ECI rank#11 of 148#25 of 148#7 of 148 (best)
GPQA DiamondGraduate-level science questions94.6% (best)—85.9%
FrontierMath Tiers 1–3Research-level mathematics82.5%74.0%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$21.00$10.00 (best)
Output$180.00$168.00$50.00 (best)
Cached input——$1.00
Blended (3:1)$67.50$57.75$20.00 (best)
Long-context rateOver 272K: $60.00 / $270.00Same rateSame rate
Price sourceOfficial OpenAI APIOfficial OpenAI APIOfficial Anthropic API
Limits
Context window1,050,000 tokens (best)400,000 tokens1,000,000 tokens
Max output128,000 tokens128,000 tokens128,000 tokens
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsNoNoYes
AudioNoNoNo
VideoNoNoNo
ReasoningYesmedium · high · xhighYesmedium · high · xhighYeslow · medium · high · xhigh · max
Tool callingYesYesYes
Structured outputNoNoYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDgpt-5.4-progpt-5.2-proclaude-fable-5
API providers16838 (best)
ReleasedMar 5, 2026Dec 11, 2025Jun 9, 2026
Knowledge cutoffAug 31, 2025Aug 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
  • GPT-5.2 Pro$546.00
  • Claude Fable 5$200.00
04 — Questions

Which should you choose?

Which is better: GPT-5.4 Pro, GPT-5.2 Pro or Claude Fable 5?

Claude Fable 5 is the better all-round choice, scoring 65/100 against GPT-5.4 Pro (60) and GPT-5.2 Pro (56). 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, GPT-5.2 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-5.2 Pro costs $21.00 input / $168.00 output per million tokens (official OpenAI 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 $57.75 for GPT-5.2 Pro (2.9× as much) and $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), GPT-5.4 Pro 159.1 (#11 of 148) and GPT-5.2 Pro 155.4 (#25 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: FrontierMath Tiers 1–3 — Claude Fable 5 87.0%, GPT-5.4 Pro 82.5%, GPT-5.2 Pro 74.0%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.4 Pro, GPT-5.2 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. All three 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 and 400,000 for GPT-5.2 Pro. Maximum output per response: GPT-5.4 Pro up to 128,000, GPT-5.2 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; GPT-5.2 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, GPT-5.2 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; GPT-5.2 Pro came out Dec 11, 2025. Knowledge cutoff: GPT-5.4 Pro Aug 31, 2025, GPT-5.2 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.