Claude Sonnet 5.5 (Medium, Default Fallback) vs Kimi K3.1 Pro
Which is better for the money: Claude Sonnet 5.5 (Medium, Default Fallback) by Anthropic or Kimi K3.1 Pro by Kimi? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-25.
Trade-off
Verdict
Depends on your budget
Kimi K3.1 Pro scores 14.3 points higher (55.1 vs 40.8) but costs 5.0× as much to run the benchmark ($3117 vs $622; flagship vs premium cost classes). They are not alternatives at one budget: pick Kimi K3.1 Pro when you need intelligence above 40.8, and Claude Sonnet 5.5 (Medium, Default Fall… when 40.8 is enough.
| Metric | Claude Sonnet 5.5 (Medium, Default Fallback) | Kimi K3.1 Pro | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 40.8 | 55.1 | +35.0% Kimi K3.1 Pro is 35.0% more intelligent |
| Total AA cost (lower is better) | $622.28 | $3,117.31 | +400.9% Kimi K3.1 Pro is 5.0× more expensive |
| End-to-end time (lower is better) | 6.11s | 49.55s | +711.0% Kimi K3.1 Pro is 711.0% slower |
| Price per 1M tokens (in / out) | $2.00 / $10.0 | $2.00 / $10.0 | |
| Input modalities | Text, Image | Text, Image |
Kimi K3.1 Pro vs Claude Sonnet 5.5 (Medium, Default Fallback): 35.0% more intelligence, 400.9% more cost to run the AA benchmark, and 711.0% slower end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Sonnet 5.5 (Medium, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (High) scores 50.20 for $521.
- Kimi K3.1 Pro is on today's frontier: nothing is both smarter and cheaper.
Claude Sonnet 5.5 (Medium, Default Fallback)Kimi K3.1 ProToday's Pareto frontierEvery other model
Matchup
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