Gemini 4 Argon vs Gemini 3.1 Pro (preview)
There is no quality verdict yet: the AIGROW small-business benchmark has not run Gemini 4 Argon. On price, Gemini 4 Argon costs less: $2 in and $10 out per million tokens, against $2 in and $12 out for Gemini 3.1 Pro (preview).
Gemini 3.1 Pro is still a preview, so its price can change. US dollars, standard rate, shortest context band. Price only: the benchmark has not run both.
- Gemini 4 Argon
- $10.00
- Gemini 3.1 Pro (preview)
- $10.80
- Gemini 4 Argon, per M tokens
- $2 / $10
- Gemini 3.1 Pro (preview), per M tokens
- $2 / $12
3,000 tokens in and 400 out each, at list price.
The new Gemini flagship against the 3.1 Pro it replaces, at the same $2 input until Argon doubles in December. 1,000 support replies cost $10.80 on Gemini 3.1 Pro (preview) and $10.00 on Gemini 4 Argon, so Gemini 3.1 Pro (preview) costs 8% more.
What each one costs
The API price per million tokens and the cheapest app plan with each model, from the makers’ own pages. Each name opens that model’s full price page.
- Gemini 4 Argon
- On the Google API, Gemini 4 Argon costs $2 per million input tokens and $10 per million output tokens. In Gemini, the cheapest plan with it is Google AI Pro at $19.99/mo. Plan prices read 20 October 2026.
- Gemini 3.1 Pro (preview)
- On the Google API, Gemini 3.1 Pro (preview) costs $2 per million input tokens and $12 per million output tokens. In Gemini, the cheapest plan with it is Google AI Pro at $19.99/mo. Plan prices read 20 October 2026.
Side by side
Each maker’s published rate for its standard tier. Cached input is what a repeated prompt prefix costs once the provider has stored it.
| Fact | Gemini 4 Argon | Gemini 3.1 Pro (preview) |
|---|---|---|
| Maker | ||
| Tier | Flagships | Flagships |
| Input, per M tokens | $2.00 | $2.00 |
| Output, per M tokens | $10.00 | $12.00 |
| Cached input | $0.10 | $0.20 |
| Context window | 1.05M | 1.05M |
| Released | 13 Oct 2026 | 19 Feb 2026 |
| Weights | Closed weights | Closed weights |
What a job costs on each
1,000 runs of each job at the two list prices. The gap moves from job to job because the models price input, output and cached context differently.
| Job | Gemini 4 Argon | Gemini 3.1 Pro (preview) | Cheaper |
|---|---|---|---|
| Support reply3,000 in, 400 out. | $10.00 | $10.80 | Gemini 4 Argon, 7% less |
| Document summary25,000 in, 1,000 out. | $60.00 | $62.00 | Gemini 4 Argon, 3% less |
| Agent task80,000 in (70,000 cached), 3,000 out. | $57.00 | $70.00 | Gemini 4 Argon, 19% less |
The token counts are ours, chosen to look like real work; the prices are the makers’. A model with no published cache price bills the agent task’s repeated context at its full input rate.
The small print
What each base rate leaves out, from the makers’ own pages: surcharges, discounts, promotions and cache pricing.
- Gemini 4 Argon
- Launch price through 2026-11-30; from 2026-12-01 it becomes $4 / $20, cached $0.20. Output includes thinking tokens. Implicit caching only. No long-context premium. Batch and Flex 50% off; Priority $3.60 / $18. Not on the Free tier. Google’s pricing page
- Gemini 3.1 Pro (preview)
- Preview model, but Google has no GA 3.x Pro and it is widely used. Prompts above 200K tokens: $4 / $18, cached $0.40. Cache storage $4.50 per MTok per hour. Batch 50% off. Max output 65,536. Google’s pricing page
Other comparisons
Every head to head on the list that involves Gemini 4 Argon or Gemini 3.1 Pro (preview).
Compare Gemini 4 Argon and Gemini 3.1 Pro (preview) with 44 other models
The price list sets every model’s input and output price side by side, with what a support reply, a document summary and an agent task cost on each.
Prices checked 15 October 2026