Old flagship versus new: $1.25/$10 tiered against $2/$12 tiered.
gemini-2.5-pro · google
gemini-3.1-pro · google
Benchmark
| Workload Scenario | Gemini 2.5 Pro | Gemini 3.1 Pro | Price Delta |
|---|---|---|---|
| 1M input tokens (raw text) | $1.25 | $2.00 | −$0.75 |
| 1M output tokens (generation) | $10.00 | $12.00 | −$2.00 |
| 1M tokens · 70% input / 30% output mix | $3.875 | $5.00 | −$1.125 |
| Standard chat turn (4K in / 800 out, 50% cached) | $0.0108 | $0.014 | −$0.00325 |
| Monthly scale (10K requests / day) | $3,225.00 | $4,200.00 | −$975.00 |
Negative difference = Gemini 2.5 Pro is cheaper. Positive = Gemini 3.1 Pro is cheaper.
Scaling Curve
Total cost of a token volume at 70/30 input/output split (uncached). Log-log scale.
Verdict
Gemini 2.5 Pro is cheaper on both input and output rates, so it costs less at every input/output mix. Price alone still isn't the whole decision: capability, latency and context limits (Gemini 2.5 Pro: 1M, Gemini 3.1 Pro: 1M) may justify the premium for your task.
FAQ
On input, Gemini 2.5 Pro is cheaper ($1.25/M vs $2.00/M). On output, Gemini 2.5 Pro is cheaper ($10.00/M vs $12.00/M). The same model is cheaper on both sides, so it wins at every mix.
A chat-style request (4,000 input + 800 output tokens, 50% cached) costs $0.0108 on Gemini 2.5 Pro and $0.014 on Gemini 3.1 Pro — Gemini 2.5 Pro is 1.3× cheaper for that workload.
Gemini 2.5 Pro supports 1,048,576 tokens (65.5K max output); Gemini 3.1 Pro supports 1,048,576 (65.5K max output). They are equal.