GPT-5.6 Sol vs Kimi K3

GPT-5.6 Sol and Kimi K3 are both current production-tier models. Kimi K3 is meaningfully cheaper at $3 / $15 per 1M. GPT-5.6 Sol leads on instruction following, vision, tool use.

Specs side by side

Metric
OpenAI
GPT-5.6 Sol
Z.ai
Kimi K3
Input price (per 1M)$5$3
Output price (per 1M)$30$15
Context window1.1M tokens1.0M tokens
Speed tierbalancedbalanced
Open weightsNoNo
EU regionYesNo
Free tierNoNo
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

OpenAI

Choose GPT-5.6 Sol if…

  • EU data residency is required
  • HIPAA eligibility is required
  • You need realtime speech-to-speech
  • Instruction following is central to your workload
  • Vision is central to your workload
Z.ai

Choose Kimi K3 if…

  • Cost is a priority ($3 / $15 per 1M vs $5 / $30 per 1M)

Benchmark delta

GPT-5.6 Sol leads on

  • Instruction following
  • Vision
  • Tool use

Kimi K3 leads on

Kimi K3 has no meaningful benchmark lead in this pair.

FAQ — GPT-5.6 Sol vs Kimi K3

GPT-5.6 Sol vs Kimi K3 — which is better?

GPT-5.6 Sol and Kimi K3 are both current production-tier models. Kimi K3 is meaningfully cheaper at $3 / $15 per 1M. GPT-5.6 Sol leads on instruction following, vision, tool use. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does GPT-5.6 Sol pricing compare to Kimi K3?

GPT-5.6 Sol costs $5 / $30 per 1M vs Kimi K3 at $3 / $15 per 1M. Kimi K3 is cheaper on output tokens by roughly 100%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does GPT-5.6 Sol or Kimi K3 have the bigger context window?

GPT-5.6 Sol has a 1.1M-token context window — 1× the 1.0M context of Kimi K3. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for GPT-5.6 Sol or Kimi K3?

GPT-5.6 Sol: no — Paid-only — no free API tier; available via ChatGPT Plus/Pro. Kimi K3: no — No free API tier; kimi.com web chat is free with limits.

Which is better for coding — GPT-5.6 Sol or Kimi K3?

GPT-5.6 Sol leads on coding benchmarks (GPT-5.6 Sol: 96/100, Kimi K3: 95/100). For production coding agents also weigh tool-use performance — GPT-5.6 Sol scores 95, Kimi K3 scores 90.