Pricing comparison

Gemini 3.1 Pro (preview) vs Gemini 2.5 Pro

Per-token pricing, full-workload cost ladders, and monthly volume projections. Numbers sourced directly from each provider's rate card.

Google

Gemini 3.1 Pro (preview)

Input
$2.00 / 1M
Output
$12.00 / 1M
Cached input
$0.200 / 1M
Context
1M
Max output
-

Google

Gemini 2.5 Pro

Input
$1.25 / 1M
Output
$10.00 / 1M
Cached input
$0.125 / 1M
Context
2M
Max output
-

Cost per request

Four common workload shapes, input tokens and a 1:2 output ratio (a standard chat/completion pattern). Long-context surcharges apply automatically where the provider charges them.

ScenarioTokens (in / out)Gemini 3.1 Pro (preview)Gemini 2.5 ProWinner
Short prompt100 / 200$0.0026$0.0021Gemini 2.5 Pro
Typical request1,000 / 2,000$0.0260$0.0213Gemini 2.5 Pro
Long document10,000 / 5,000$0.0800$0.0625Gemini 2.5 Pro
Large prompt100,000 / 10,000$0.3200$0.2250Gemini 2.5 Pro

Monthly bill at scale

Projected monthly cost at typical request volume, assuming the "typical request" shape above (1k in, 2k out).

TrafficReq / monthGemini 3.1 Pro (preview)Gemini 2.5 ProDelta
Small SaaS1,000$26.00$21.25Gemini 2.5 Pro -$4.75
Growing product10,000$260.00$212.50Gemini 2.5 Pro -$47.50
Heavy usage100,000$2,600$2,125Gemini 2.5 Pro -$475.00

Which should you use?

For the typical chat-shape request (~1k input, 2k output), Gemini 2.5 Pro comes out 22% cheaper. If you're picking one as the default, that's usually the right choice on cost alone.

Gemini 2.5 Pro wins on both sides of the bill - cheaper input and cheaper output. If the quality gap is in your favour, there's no cost argument for the other side.

Context window differs: Gemini 2.5 Pro holds 2M of input vs 1M on the other side. If you regularly push past the smaller ceiling, the comparison ends there.

Heads-up: Gemini 3.1 Pro (preview) applies a long-context surcharge above 200K input tokens ($4.00 input / $18.00 output per 1M). Workloads that push past that threshold pay roughly 2x the numbers above.

Live cost calculator

Type in any token counts - both prices update instantly. Uses base input/output rates (no cache discount, no long-context tier).

Gemini 3.1 Pro (preview)

$0.0080

per request

Gemini 2.5 Pro

$0.0063

per request

Gemini 2.5 Pro is $0.0017 cheaper per request (21.9% less).

Try both in the estimator →

Drop your actual prompt in, tokens are counted with the provider's own tokenizer, and the dollar number matches what lands on your invoice.

Frequently asked

Which is cheaper, Gemini 3.1 Pro (preview) or Gemini 2.5 Pro?
On a typical 1,000-input / 2,000-output request, Gemini 2.5 Pro costs ~$0.0213 vs ~$0.0260 on Gemini 3.1 Pro (preview). Input or output rates can flip the answer for very lopsided workloads - see the cost ladder above.
What's the difference in per-token pricing?
Gemini 3.1 Pro (preview) charges $2.00 per 1M input tokens and $12.00 per 1M output tokens. Gemini 2.5 Pro charges $1.25 / $10.00 per 1M.
Which has the bigger context window?
Gemini 2.5 Pro is larger (2M) vs 1M on the other.
Is there a cached-input discount on either?
Gemini 3.1 Pro (preview) caches at $0.200 per 1M (90% off). Gemini 2.5 Pro caches at $0.125 per 1M (90% off). Workloads with repeated static prefixes see the biggest savings.
Does Gemini 3.1 Pro (preview) have a long-context surcharge?
Yes. Above 200K input tokens, Gemini 3.1 Pro (preview) bills at $4.00 input / $18.00 output per 1M instead of the standard rate.
How fresh is this comparison?
Gemini 3.1 Pro (preview) was re-verified on 2026-04-06 and Gemini 2.5 Pro on 2026-04-06 against each provider's published rate card. Calcis re-checks every row on a rolling schedule and re-deploys when a provider changes pricing.

Gemini 3.1 Pro (preview) verified 2026-04-06 · Gemini 2.5 Pro verified 2026-04-06. Rate cards at Google.