Head-to-head
ChatGPT‑6 vs GPT-5.6 Sol
GPT-5.6 Sol is the mature, all-round leader of the last generation. ChatGPT-6 trades blows on quality, matches its context, and costs nothing during preview.
OpenAI
GPT-5.6 Sol set the bar for the previous generation — strong agentic coding and the most mature tooling around it. ChatGPT-6 pushes ahead on general intelligence and coding, matches the 400K context, and is free while in early access. For raw exploration and long-context work the value is lopsided; if you depend on OpenAI's official SDKs and support today, GPT-5.6 still has the ecosystem edge.
Side by side
The same figures from our full benchmark table, narrowed to two columns.
| Metric | ChatGPT-6 | GPT-5.6 |
|---|---|---|
| Intelligence Index | 71* | 67 |
| Agentic coding | 86* | 84 |
| Context window | 400K | 400K |
| Max output | 128K | 128K |
| Throughput (tps) | 58* | 70 |
| Price / 1M out | $0 | $10 |
| Multimodal | ||
| Open weights | ||
| Free to use |
- Free during preview vs about $10 per million output tokens
- Higher composite intelligence and agentic-coding score
- Same 400K-token context window
- No account, no app to get started
- Battle-tested SDKs, tools and integrations
- An officially supported API with an SLA
- A public roadmap and vendor support
Which should you choose?
You want a clear step up in reasoning and coding at zero cost, and you're comfortable on a preview.
You need a production guarantee and OpenAI's official tooling today.
Try ChatGPT-6 free
No account, no card, no app — open the chat and compare for yourself.