Compare GPT 5.5 from OpenAI and Kimi K3 from Moonshot AI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
GPT 5.5
Kimi K3GPT-5.5 raises the baseline for complex production workflows. It’s a strong fit for coding use cases, tool-heavy agents, grounded assistants, long-context retrieval, product-spec-to-plan workflows, and customer-facing workflows where execution quality and response polish are critical.
Kimi K3 is Kimi’s flagship model for long-horizon coding and end-to-end knowledge work, with a 1M-token context window and industry-leading intelligence.
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
Promotional prices show the discounted rate; see each model page for promotion windows.
Daily traffic served through AIHubMix — how demand for each model is trending.
Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.
LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.
Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.
Estimate your monthly bill for the same workload on each model.
Monthly = daily × 30. Discounted rates applied where a promotion is active.
Kimi K3: $13.5/M output tokens; GPT 5.5: $30/M. Use the cost calculator above to estimate your own workload.
Kimi K3: 1531; GPT 5.5: 1509 (LMArena coding leaderboard).
Kimi K3: 0.9s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.
GPT 5.5 accepts 1,050,000 and Kimi K3 accepts 1,048,576 input tokens. Maximum output per request is 128,000 tokens on GPT 5.5 and 1,048,576 tokens on Kimi K3.
Kimi K3 at 73.1 tok/s and GPT 5.5 at 64.4 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.
GPT 5.5 accepts text and image input and supports thinking, function calling, structured outputs, web search and tool calling; Kimi K3 accepts text, image and video input and supports thinking, function calling and structured outputs.
Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.
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