Claude 2.1 vs Claude Opus 5.5 (Low, Default Fallback)

Claude 2.1 vs Claude Opus 5.5 (Low, Default Fallback). A reliable intelligence-versus-cost verdict requires both models' intelligence scores and benchmark-run costs. Missing data is not a performance verdict.

AnthropicClaude 2.1Not ranked · benchmark data missing
Intelligence
5.60
Total cost
-
AnthropicClaude Opus 5.5 (Low, Default Fallback)Off the frontier
Intelligence
42.30
Total cost
$860
Verdict

Comparison incomplete

A reliable intelligence-versus-cost verdict requires both models' intelligence scores and benchmark-run costs. Missing data is not a performance verdict.

MetricClaude 2.1Claude Opus 5.5 (Low, Default Fallback)Difference
Intelligence (higher is better)5.642.3+655.4% Claude Opus 5.5 (Low,… is 7.6× more intelligent
Total AA cost (lower is better)Not reported$860.33— not comparable
End-to-end time (lower is better)Not reported11.47s— not comparable
Price per 1M tokens (in / out)—$4.00 / $20.0
Input modalitiesTextText, Image
Open this matchup in the interactive pickerClaude 2.1: what beats itClaude Opus 5.5 (Low, Default Fallback): what beats it
Matchup

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Agents: Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-21/claude-opus-5-5-low · Markdown: /api/v1/compare/claude-21/claude-opus-5-5-low?format=md · llms.txt · agent skill