Claude Opus 5.5 Max vs Kimi K3.1 Pro: latency, speed and cost

Claude Opus 5.5 (Max, Default Fallback) (Anthropic) and Kimi K3.1 Pro (Kimi) are not peers on the headline index, which makes the trade-offs the interesting part. Kimi K3.1 Pro starts answering far sooner, with a time to first token of 3.0 seconds compared with 10.8 minutes for Claude Opus 5.5 Max. This page is written automatically from catalogue numbers only: benchmark scores, list prices and measured speed.

Claude Opus 5.5 Max is the faster writer

Once a response is under way, Claude Opus 5.5 Max produces roughly 95 tokens per second against 27 tokens per second for Kimi K3.1 Pro. That makes Claude Opus 5.5 Max roughly 3.5 times as fast at writing. The wait for the first token averages 10.8 minutes on Claude Opus 5.5 Max against 3.0 seconds on Kimi K3.1 Pro. On total time, Kimi K3.1 Pro wins at ordinary lengths; Claude Opus 5.5 Max's higher throughput only pays off beyond about 24,000 tokens. Waits that long are felt on every chat-style request, though they matter less for batch jobs.

For an 800-token response, first token plus generation comes to roughly 10.9 minutes on Claude Opus 5.5 Max and 33 seconds on Kimi K3.1 Pro.

Running costs

Claude Opus 5.5 Max lists $4.00 per million input tokens and $20.00 per million output tokens; Kimi K3.1 Pro lists $2.00 and $10.00. Claude Opus 5.5 Max costs twice as much per output token.

For a sample workload of 1 million input tokens and 200,000 output tokens, Claude Opus 5.5 Max would cost $8.00 and Kimi K3.1 Pro $4.00, a difference of $4.00. For classifying 100,000 short messages at 150 input tokens and 5 output tokens each, Kimi K3.1 Pro would come in 50% lower: $70.00 for Claude Opus 5.5 Max against $35.00 for Kimi K3.1 Pro.

The headline benchmark

Claude Opus 5.5 Max comes out ahead on the intelligence index, 59.1 to 46.5. This is a substantial lead, not a near miss. Put another way, Kimi K3.1 Pro would need 27% more on this index to draw level.

Among 109 active scored models, Claude Opus 5.5 Max sits 2nd and Kimi K3.1 Pro 23rd.

Specialist coding and math indexes are missing for both, so treat the overall score as the only capability signal here.

Score per dollar

A blunt value measure, blended price over intelligence score, puts Claude Opus 5.5 Max at $0.14 and Kimi K3.1 Pro at $0.086 per point. So Claude Opus 5.5 Max buys its higher score at a premium, while Kimi K3.1 Pro is the value pick, paying 36% less per point.

Release timing

The release dates are September 22, 2026 for Claude Opus 5.5 Max and October 23, 2026 for Kimi K3.1 Pro, 31 days apart. They are effectively contemporaries.