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Comparison · 2 models · Updated Oct 4, 2026

Claude Fable 5 vs Claude Opus 4.5

Claude Fable 5 comes out ahead, 65 to 55 on our weighted score, though Claude Opus 4.5 is 2× cheaper per token.

  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. Anthropic

    Claude Opus 4.5

    Released Nov 24, 2025

    55/100
    • ECI150.1
    • Price$5.00 / $25.00
    • Context200K
    Full specs Remove Claude Opus 4.5

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    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 Claude Opus 4.5 (55). It leads on capability and context window. Claude Opus 4.5 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Fable 5Capabilities Index (ECI): Claude Fable 5 162.2 · Claude Opus 4.5 150.1
  • Lowest priceClaude Opus 4.5Claude Opus 4.5 $10.00 · Claude Fable 5 $20.00 per 1M tokens (3:1 blend)
  • Longest contextClaude Fable 5Claude Fable 5 1,000,000 · Claude Opus 4.5 200,000 tokens
  • Widest inputsSame inputsClaude Fable 5: Text, Images, PDFs · Claude Opus 4.5: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Fable 5Claude Opus 4.5
CapabilityCapabilities Index (ECI)50%9478
Price25%02
Inputs & features15%8080
Context window10%6032
Overall100%65/10055/100
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 Claude Opus 4.5 specifications side by side
SpecificationClaude Fable 5AnthropicClaude Opus 4.5Anthropic
Capability
Capabilities Index (ECI)162.2 (best)150.1
ECI rank#7 of 148 (best)#48 of 148
GPQA DiamondGraduate-level science questions85.9%86.1% (best)
FrontierMath Tiers 1–3Research-level mathematics87.0% (best)34.4%
OTIS Mock AIME 2024–2025Competition mathematics100% (best)86.1%
SWE-bench VerifiedFixing real GitHub issues—76.7%
SimpleQA VerifiedShort factual questions70.7% (best)45.7%
Price per million tokens
Input$10.00$5.00 (best)
Output$50.00$25.00 (best)
Cached input$1.00$0.50 (best)
Blended (3:1)$20.00$10.00 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Anthropic API
Limits
Context window1,000,000 tokens (best)200,000 tokens
Max output128,000 tokens (best)64,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhigh · maxYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDclaude-fable-5claude-opus-4-5
API providers38 (best)28
ReleasedJun 9, 2026Nov 24, 2025
Knowledge cutoffJan 31, 2026May 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
  • Claude Opus 4.5$100.00
04 — Questions

Which should you choose?

Which is better: Claude Fable 5 or Claude Opus 4.5?

Claude Fable 5 is the better all-round choice, scoring 65/100 against Claude Opus 4.5 (55). It leads on capability and context window. Claude Opus 4.5 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Fable 5 or Claude Opus 4.5?

Claude Opus 4.5 is cheaper at $5.00 input / $25.00 output per million tokens (official Anthropic 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 $10.00 per million tokens for Claude Opus 4.5 versus $20.00 for Claude Fable 5 (2× 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 Claude Opus 4.5 150.1 (#48 of 148). Their confidence ranges do not overlap (159.6–166.1 vs 147.9–153.0), so the gap is a real one. On individual benchmarks: GPQA Diamond — Claude Opus 4.5 86.1%, Claude Fable 5 85.9%; FrontierMath Tiers 1–3 — Claude Fable 5 87.0%, Claude Opus 4.5 34.4%; OTIS Mock AIME 2024–2025 — Claude Fable 5 100%, Claude Opus 4.5 86.1%; SimpleQA Verified — Claude Fable 5 70.7%, Claude Opus 4.5 45.7%.

Which is better for coding?

There are no published SWE-bench Verified results for 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?

Claude Fable 5 has the largest context window at 1,000,000 tokens, against 200,000 for Claude Opus 4.5. Maximum output per response: Claude Fable 5 up to 128,000, Claude Opus 4.5 up to 64,000 tokens.

Which can read images, PDFs, audio or video?

Claude Fable 5 accepts text, images and PDFs; Claude Opus 4.5 accepts text, images and PDFs. They handle the same number of input types.

Are any of these open source?

No. Claude Fable 5 and Claude Opus 4.5 are proprietary and only available through APIs and apps.

Which is newer?

Claude Fable 5 is the newest, released Jun 9, 2026. Claude Opus 4.5 came out Nov 24, 2025. Knowledge cutoff: Claude Fable 5 Jan 31, 2026, Claude Opus 4.5 May 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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