Claude 4.5 Sonnet (Reasoning) vs Claude Opus 5.5 (High, Default Fallback)

Which is better for the money: Claude 4.5 Sonnet (Reasoning) by Anthropic or Claude Opus 5.5 (High, Default Fallback) by Anthropic? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.

Trade-off

AnthropicClaude 4.5 Sonnet (Reasoning)Off the frontier

Intelligence: 20.70
Total cost: $1501

AnthropicClaude Opus 5.5 (High, Default Fallback)On the frontier

Intelligence: 53.60
Total cost: $2172

Verdict

Depends on your budget

Claude Opus 5.5 (High, Default Fallback) scores 32.9 points higher (53.6 vs 20.7) but costs 1.4× as much to run the benchmark ($2172 vs $1501; flagship vs premium cost classes). Pick Claude Opus 5.5 (High, Default Fallback) when the extra intelligence is worth the premium, otherwise Claude 4.5 Sonnet (Reasoning).

Metric	Claude 4.5 Sonnet (Reasoning)	Claude Opus 5.5 (High, Default Fallback)	Difference
Intelligence (higher is better)	20.7	53.6	+158.9% Claude Opus 5.5 (High… is 2.6× more intelligent
Total AA cost (lower is better)	$1,501.22	$2,172.43	+44.7% Claude Opus 5.5 (High… is 44.7% more expensive
End-to-end time (lower is better)	20.84s	33.81s	+62.2% Claude Opus 5.5 (High… is 62.2% slower
Price per 1M tokens (in / out)	$3.00 / $15.0	$4.00 / $20.0
Input modalities	Text, Image	Text, Image

Claude Opus 5.5 (High, Default Fallback) vs Claude 4.5 Sonnet (Reasoning): 158.9% more intelligence, 44.7% more cost to run the AA benchmark, and 62.2% slower end-to-end.

Open this matchup in the interactive picker Claude 4.5 Sonnet (Reasoning): what beats it Claude Opus 5.5 (High, Default Fallback): what beats it

Today's Pareto frontier

Against the frontier

Claude 4.5 Sonnet (Reasoning) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
Claude Opus 5.5 (High, Default Fallback) is on today's frontier: nothing is both smarter and cheaper.

Claude 4.5 Sonnet (Reasoning)Claude Opus 5.5 (High, Default Fallback)Today's Pareto frontierEvery other model

Matchup

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Agents: Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-4-5-sonnet-thinking/claude-opus-5-5-high · Markdown: /api/v1/compare/claude-4-5-sonnet-thinking/claude-opus-5-5-high?format=md · llms.txt · agent skill