Comparisons › GPT-6 Astra vs GPT-5.6 Sol: is the new top tier worth 2.5x?

GPT-6 Astra vs GPT-5.6 Sol: is the new top tier worth 2.5x?

OpenAI's two most capable text models sit 2.5x apart on price. The question is whether the top tier earns it, or whether Sol is the value pick of the two.

Value verdict: on intelligence per $1, ChatGPT currently comes out ahead — 13,250 vs 29,375. Prices move often, so recheck the calculator regularly.

At a glance

Model compared

GPT-6 Astra	GPT-5.6 Sol	ChatGPT
Flagship model	GPT-6 Astra	GPT-5.6 Sol
Input / 1M	$10	$4
Output / 1M	$50	$20
Intelligence index	53	47
Tokens / $1	25.0k	62.5k
Intelligence / $1	13,250	29,375

Price

GPT-6 Astra is $10 / $50 per 1M tokens. GPT-5.6 Sol is $4 / $20 — and that is a promotional rate through 21 November 2026, so the gap can widen to $10 / $50 versus $8 / $30 for long-context work. Astra costs 2.5x more on both axes today.

Capability

Astra is the newer model and sits higher on the intelligence index — it is OpenAI's answer to the current top tier. Sol is one step back and remains one of the strongest models on the site, particularly for back-end work and bug fixing with close guidance.

When to pick which

Choose Astra for short, expensive, high-stakes tasks: architecture decisions, hard debugging, agentic runs where a wrong first attempt costs more than the tokens. Choose Sol for anything high-volume — refactors, test generation, bulk content — where the 2.5x saving compounds far faster than the quality difference. Price the switch in the calculator with your own monthly volume.

Bottom line: Astra for the hardest, lowest-volume work where one-shot quality matters; Sol for everything else. Sol costs 2.5x less and is still one of the strongest models in the catalog — for most workloads it is the better buy.