GPT Sol vs Kimi
The open-versus-closed question at the top of the market. Sol scores higher and comes with the largest ecosystem; Kimi K3 is open-weight, comparable in context, and dramatically cheaper to run through a provider or on your own hardware. In 2026 the open models are close enough that this is a deployment decision, not a capability one.
| GPT Sol | Kimi | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Current release | GPT-5.6 Sol | K3 |
| Tier | Frontier | Open weights |
| Context | 1M | 1M |
| Cost | Premium | Low cost |
| Modalities | text, vision | text, vision |
| Open weights | No | Yes |
Cost is a tier, not a quote, providers change prices often. Check OpenAI and Moonshot AI before you commit. Last updated 2026-09-04.
Which one to pick
GPT SolOpenAI · GPT-5.6 Sol
Frontier-grade generalist work now that Astra has taken the top of the line
Reach for it when- Best available generalist quality with no ops burden
- The largest third-party tooling ecosystem
KimiMoonshot AI · K3
Frontier-adjacent quality you can self-host, the open model closest to the closed leaders
Reach for it when- Self-hosting, on-prem, or strict data residency
- Very high volume where the token bill dominates
Related comparisons
- GPT Astra vs GPT SolThe within-OpenAI upgrade question.
- Claude Opus vs GPT SolTwo mid-frontier models at almost the same price, now that GPT-6 Astra sits above Sol and Claude Fable 5.1 sits above Opus.
- GPT Sol vs Gemini ProSol is the stronger all-round generalist; Gemini 3.1 Pro is the better value and the reasoning-benchmark leader.
- GPT Sol vs GrokSol is the safer default and scores higher overall; Grok 4.6 matches it on some agentic work at a fraction of the short-context price.
- GPT Sol vs GPT TerraSame family, same million-token context, different price and depth.
- Claude Opus vs KimiClosed frontier against the open model that got closest to it.