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2026 comparison

ChatGPT-5.5 vs Claude Fable 5

Side-by-side analysis, no fluff. We've tested both in real-world conditions.

Summary table

Criterion
Winner
C
ChatGPT-5.5

Freemium

C
Claude Fable 5

Paid

Score
4.5 / 5
4.5 / 5
Category
Chatbots & Assistants
Chatbots & Assistants
Pricing model
Freemium
Paid
Starting price
$20/mo
Pay-per-token
Badge
New
New
C

What's best about ChatGPT-5.5

  • Excellent speed-to-intelligence ratio with GPT-5.5 Instant
  • Massive 512K context window for flagship GPT-5.5
  • Very competitive API token pricing ($4/$12 per 1M)
  • Superb developer and Custom GPT ecosystem
C

What's best about Claude Fable 5

  • Absolute leadership in complex logic and agent planning autonomy
  • Massive 1 million token input context window
  • Extended output capacity of up to 128k tokens
  • Integrated proactive safety via automatic routing to Opus
C

What's weakest about ChatGPT-5.5

  • Trails Claude Fable 5 on complex multi-file software engineering tasks
  • Plus consumer caps still apply during peak traffic hours
C

What's weakest about Claude Fable 5

  • High output token cost ($50/M) for bulk generation tasks
  • Strict safety classifiers that trigger rerouting on sensitive inputs
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Quick verdict

Technical tie — depends on your use case

Frequently asked questions

Which is better, ChatGPT-5.5 or Claude Fable 5?+

ChatGPT-5.5 and Claude Fable 5 are neck and neck — both score 4.5/5 in our tests. Flagship intelligence with GPT-5.5 and ultra-fast GPT-5.5 Instant. The new standard of "Mythos-Class" intelligence with deep autonomous reasoning.

Does ChatGPT-5.5 have a free plan?+

Yes, ChatGPT-5.5 has a free plan available. Paid plans start at $20/mo.

Does Claude Fable 5 have a free plan?+

No, Claude Fable 5 is paid-only. Pricing starts at Pay-per-token.

How does ChatGPT-5.5 differ from Claude Fable 5?+

ChatGPT-5.5 stands out for: Excellent speed-to-intelligence ratio with GPT-5.5 Instant; Massive 512K context window for flagship GPT-5.5. Claude Fable 5 excels at: Absolute leadership in complex logic and agent planning autonomy; Massive 1 million token input context window.