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LLM Toolkit

Model comparison

Claude Fable 5 vs Claude Opus 5

Verified pricing, context windows and real-workload costs for both models — computed from official provider rates as of 2026-09-02.

Cheaper input

Claude Opus 5

$5.00 /1M in

Cheaper output

Claude Opus 5

$25.00 /1M out

Bigger context

Tie — both models

1M tokens each

Head to head

Spec Claude Fable 5 Claude Opus 5
Input / 1M tokens $10.00 $5.00
Cached input / 1M $1.00 $0.50
Output / 1M tokens $50.00 $25.00
Context window 1M 1M
Provider Anthropic Anthropic
Price verified 2026-09-02 2026-09-02

Monthly cost at three real workloads

Workload Claude Fable 5 Claude Opus 5 Winner
Side-project chatbot 30K req · 2,000 in / 500 out · 40% cached $1,134/mo $567.00/mo Claude Opus 5
Coding agent 500K req · 12,000 in / 1,500 out · 70% cached $59,700/mo $29,850/mo Claude Opus 5
Bulk extraction 2,000K req · 800 in / 120 out · 20% cached $25,120/mo $12,560/mo Claude Opus 5

Computed from list prices verified 2026-09-02. Cache savings blend normal and cached input rates by the hit rate; models without published cached rates use the base input price. Adjust every parameter yourself on the API Cost Calculator.

Pick Claude Fable 5 if…

  • You prefer its $10.00 input rate for read-heavy workloads.
  • Its 1M window matches Claude Opus 5 — context is not a differentiator here.
  • You value its provider ecosystem and tooling.

Pick Claude Opus 5 if…

  • You generate long outputs — $25.00 per 1M output vs $50.00 adds up fast.
  • Its 1M window covers your typical request with headroom.
  • You want cheaper total spend at your exact volumes — verify with the calculator above.

Frequently asked questions

Is Claude Fable 5 cheaper than Claude Opus 5?

Claude Opus 5 is cheaper on input at $5.00 per 1M tokens vs $10.00 — input pricing is 2.0× more expensive. On output, Claude Opus 5 wins at $25.00 vs $50.00. At a balanced workload (100K requests, 2K in / 500 out), Claude Opus 5 runs $2,250/mo vs $4,500/mo — a 2.0× difference.

Claude Fable 5 vs Claude Opus 5: which has the bigger context window?

Neither — both ship the same 1M context window. Filling it once costs $10.00 on Claude Fable 5 at list price, vs $5.00 on Claude Opus 5.

Should I switch from Claude Fable 5 to Claude Opus 5?

Switch if your bottleneck matches Claude Opus 5's strengths: its 1M context fits your documents and cheaper output tokens ($25.00 vs $50.00). Stay on Claude Fable 5 if your workload already fits its limits. Test both with your real token counts before committing.

Keep comparing

Or measure your real usage with the AI Token Counter and browse all rates on the Pricing Comparison.