GPT-5.5 Pro vs Kimi K2.5
Verdict
GPT-5.5 Pro leads 7–0 across 7 shared benchmarks.
GPT-5.5 Pro 7 · Kimi K2.5 0 · higher isn't always better — see caveats.
Per-benchmark head-to-head
Reported scores — protocols may differ. How we compare
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GPT-5.5 ProKimi K2.5
Capabilities
Reasoning
Reasoning: GPT-5.5 Pro leads 4–0 across 4 shared reasoning benchmarks (largest gap: SimpleBench, 72.28 vs 36.16 — single evaluator).
4 reproduced4 unverified
What the labs claim
Vendor claims — compare against the measured scores above. A claim is what a developer says about its own model, not an independent measurement.
GPT-5.5 Pro
General
“In GPT-5.5 Pro, early testers are seeing a significant step up in both the difficulty and quality of work ChatGPT can take on”
openai.com2026
Reasoning
“GPT-5.5 Pro, designed for even harder questions and higher-accuracy work, is available to Pro, Business, and Enterprise users.”
openai.com2026
Writing
“testers found GPT-5.5 Pro's responses significantly more comprehensive, well-structured, accurate, relevant, and useful”
openai.com2026
Kimi K2.5
Agentic / Tool Use
“It seamlessly integrates vision and language understanding with advanced agentic capabilities, instant and thinking modes, as well as conversational and agentic paradigms.”
github.com2026“K2.5 transitions from single-agent scaling to a self-directed, coordinated swarm-like execution scheme.”
github.com2026
Coding
“K2.5 generates code from visual specifications (UI designs, video workflows) and autonomously orchestrates tools for visual data processing.”
github.com2026
Multimodal
“Kimi K2.5 is an open-source, native multimodal agentic model built through continual pretraining on approximately 15 trillion mixed visual and text tokens atop Kimi-K2-Base.”
github.com2026