
GPT-6 Sol vs Opus 5.5: Price and Benchmarks
The Short Version Sol and Luna are not new names: they arrived this summer as part of GPT-5.6. On 22 September 2026 OpenAI moved both to GPT-6 and halved the price, roughly 90 minutes after Anthropic shipped Claude Opus 5.5. Sol: $2 in / $10 out per million tokens. Opus 5.5 is $4 / $20, so Sol is exactly half. Luna: $0.10 / $0.50, 40x cheaper than Opus 5.5. Free and Go users get it in the ChatGPT desktop app. Every OpenAI chart compares against Opus 5, not Opus 5.5. On the one benchmark both vendors report, Opus 5.5 leads: 40.0% vs 33.2% on AutomationBench. Pick Opus 5.5 for quality, Sol for volume, Luna for simple high-volume jobs. GPT-6 Sol vs GPT-5.6 Sol: What Changed? The Sol, Terra and Luna tiers first shipped this summer with GPT-5.6 . Earlier this month GPT-6 Astra took the top slot, while Sol and Luna stayed on GPT-5.6. This release moves those two onto the GPT-6 generation: Sol for coding and agentic work, Luna for high-volume jobs with a clear goal, such as summarising documents, extracting fields or answering quick questions. ...
