Gemini 3.1 Pro vs GPT-6 Astra (2026): Which AI Model Is Better?

Both are popular language models. Here is how Gemini 3.1 Pro and GPT-6 Astra stack up on price, strengths and weaknesses, and which one we would pick.

Gemini 3.1 Pro

Google's Gemini models (3.1 Pro, 3.8 Flash) in the Gemini app, NotebookLM and the Gemini API

8.7 /10

Pricing: Free plan, paid from $4.99/mo

Pros

Gemini 3.8 Flash API price is $0.75 in / $3.75 out per million tokens until end of 2026
Free tier in the Gemini app and a free (rate-limited) API tier in AI Studio
Google AI Plus starts at $4.99 per month in the US
Same account unlocks Nano Banana images and Flow video

Cons

Gemini 3.5 Pro was announced in May 2026 but has not shipped; the Pro tier is still 3.1
Free API tier content may be used to improve Google's products
Gemini 3.8 Flash price doubles after 31 December 2026
Frequent Flash versions (3.5, 3.6, 3.7, 3.8 in four months) make pinning outputs harder

Visit Gemini 3.1 Pro ↗

GPT-6 Astra

OpenAI's GPT-6 family (Astra, Sol, Luna) behind ChatGPT and the OpenAI API

9.0 /10

Pricing: Free plan, paid from $8/mo

Pros

Three tiers let you trade quality for cost: Astra, Sol and Luna
GPT-6 Sol and Luna API prices are half of the GPT-5.6 equivalents
Same model family powers ChatGPT, so drafts and API output behave alike
Wide third-party support in automation tools such as n8n, Make and Zapier

Cons

GPT-6 Astra is expensive on the API at $10 in / $50 out per million tokens
Sol is limited to paid ChatGPT plans; free users get Luna
Closed weights: you cannot self-host or fine-tune locally
Fast release cadence means prompts and outputs shift every few months

Visit GPT-6 Astra ↗

Gemini 3.1 Pro vs GPT-6 Astra at a glance

	Gemini 3.1 Pro	GPT-6 Astra
Editor score	8.7 / 10	9.0 / 10
Pricing model	Freemium	Freemium
Starting price	$4.99/mo	$8/mo
Reader upvotes	0	0
Best for	llm, google, gemini	llm, openai, chatgpt
Makes	Blog posts & articles, Ad & marketing copy, Emails & newsletters, Scripts & outlines	Blog posts & articles, Ad & marketing copy, Emails & newsletters, Scripts & outlines
Maker	Google DeepMind	OpenAI
Latest release	2026-02	2026-09
Apps offering it	10	17

Our pick

GPT-6 Astra edges it with a score of 9.0 versus 8.7. GPT-6 Astra is the better fit if you value: three tiers let you trade quality for cost: astra, sol and luna, gpt-6 sol and luna api prices are half of the gpt-5.6 equivalents. Choose Gemini 3.1 Pro instead if you need: gemini 3.8 flash api price is $0.75 in / $3.75 out per million tokens until end of 2026, free tier in the gemini app and a free (rate-limited) api tier in ai studio.