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Gemini 3.1 Pro vs Gemini 3.8 Flash: price
Gemini 3.8 Flash is 3.0× cheaper than Gemini 3.1 Pro for a typical chat workload (1,500 tokens in, 500 out).
| Item | Gemini 3.1 Pro | Gemini 3.8 Flash |
|---|---|---|
| Input per 1M tokens | $2.00 | $0.75 |
| Output per 1M tokens | $12.00 | $3.75 |
| Cached input per 1M | $0.20 | $0.075 |
| 1,000 chat messages1,500 tokens in, 500 out each | $9.00 | $3.00 |
| Summarize a 50-page PDF30,000 tokens in, 1,000 out | $0.072 | $0.026 |
| One coding-agent task60,000 tokens in, 4,000 out, no caching | $0.168 | $0.06 |
Gemini 3.8 Flash: Promo price through Dec 31, 2026; $1.50 in / $7.50 out from Jan 1, 2027.
List prices checked September 28, 2026. Price is half the story: see how people rate each one today.
Gemini 3.1 Pro vs Gemini 3.8 Flash in numbers
Output, usually the bigger part of the bill, costs $12.00 on Gemini 3.1 Pro and $3.75 on Gemini 3.8 Flash, so Gemini 3.8 Flash is 3.2× cheaper there. Input costs $2.00 versus $0.75 per million tokens. For a coding-agent task (60,000 tokens in, 4,000 out) that is $0.168 on Gemini 3.1 Pro and $0.06 on Gemini 3.8 Flash. Both accept up to 1.05M tokens of context. Gemini 3.1 Pro came out on February 19, 2026 and Gemini 3.8 Flash on September 2, 2026.
Both are Google models. Estimate your own bill for both in the cost calculator.
Which one feels dumber today?
- Gemini 3.1 ProGoogle
–no votes yet - Gemini 3.8 FlashGoogle–no votes yet
Frequently asked questions
Is Gemini 3.1 Pro or Gemini 3.8 Flash cheaper?
Gemini 3.8 Flash is 3.0× cheaper than Gemini 3.1 Pro for a typical chat workload (1,500 tokens in, 500 out). Output, usually the bigger part of the bill, costs $12.00 on Gemini 3.1 Pro and $3.75 on Gemini 3.8 Flash, so Gemini 3.8 Flash is 3.2× cheaper there.
Which is better, Gemini 3.1 Pro or Gemini 3.8 Flash?
It depends on the task, and price is only part of it. Check how people rate each one today on the Gemini 3.1 Pro and Gemini 3.8 Flash pages, and read what users report in Discussions.