# Gemini 2.5 Pro vs Gemini 3.5 Flash-Lite

Gemini 3.5 Flash-Lite is one of Google's newest models and Gemini 2.5 Pro an earlier one, so this is also what moving up costs or saves. Gemini 3.5 Flash-Lite is the cheaper of the 2: for the same tokens, 3 read for each 1 written, Gemini 2.5 Pro costs 4 times as much. Below are both price lists, what 8 everyday jobs cost a month on each, and how many tokens the same text takes on each, which can change the answer.

- Page, with a calculator for your own job: https://tecyfy.com/prices/compare/gemini-2-5-pro-vs-gemini-3-5-flash-lite
- Makers: Gemini 2.5 Pro from Google, Gemini 3.5 Flash-Lite from Google

## Price per million tokens, in US dollars

| | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite |
| --- | --: | --: |
| Input | $1.25 | $0.30 |
| Cached input | $0.125 | $0.03 |
| Cache write | not listed | not listed |
| Output | $10 | $2.50 |
| Blend, 3 read for each 1 written | $3.4375 | $0.85 |
| Batch input | not listed | not listed |
| Batch output | not listed | not listed |
| Long prompt input (above 200K on Gemini 2.5 Pro) | $2.50 | $0.30 |
| Long prompt output | $15 | $2.50 |
| Context window, tokens | 1.05M | 1.05M |
| Capability score (Epoch Capabilities Index; GPT-5 is 150) | not listed | 145 |
| Longest answer, tokens | 66K | 66K |

## What 8 everyday jobs cost a month on each

Each job at its usual runs a day, for 30 days, at the standard price.

| Job | Tokens in, out, runs a day | Gemini 2.5 Pro | Gemini 3.5 Flash-Lite |
| --- | --- | --: | --: |
| A chat question | 300, 500, 100 | $16.13 | $4.02 |
| A hard question, with thinking | 300, 1,400, 100 | $43.13 | $10.77 |
| A long report, summarised | 60,000, 2,000, 20 | $57.00 | $13.80 |
| A 40-turn agent task | 2,800,000, 40,000, 10 | $320 | $77.88 |
| A support bot's reply | 4,000, 300, 2,000 | $345 | $84.60 |
| Sort a message into a category | 250, 5, 50,000 | $544 | $131 |
| Read an invoice into fields | 1,500, 250, 1,000 | $131 | $32.25 |
| Review a pull request | 25,000, 4,500, 50 | $114 | $28.13 |

## Questions

### Which is cheaper, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite is cheaper: $0.30 per million tokens read and $2.50 per million written, against $1.25 and $10 on Gemini 2.5 Pro. On a mix of 3 tokens read for each 1 written, Gemini 2.5 Pro costs 4 times as much.

### Which is better, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite scores 145 on the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks (GPT-5 is 150). Gemini 2.5 Pro has no independent score yet, so the only fair test is to run the same 10 tasks on both.

### What does a support bot cost a month on Gemini 2.5 Pro and Gemini 3.5 Flash-Lite?

At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $345 a month on Gemini 2.5 Pro and $84.60 on Gemini 3.5 Flash-Lite: Gemini 2.5 Pro costs 4.1 times as much for this job.

### What does an AI agent task cost on Gemini 2.5 Pro and Gemini 3.5 Flash-Lite?

One 40-turn task that reads 2,800,000 tokens in all, 90 percent of them from cache, and writes 40,000, costs $1.07 on Gemini 2.5 Pro and 26 cents on Gemini 3.5 Flash-Lite. At 10 tasks a day that is $320 and $77.88 a month.

### Which has the larger context window, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Neither: both hold 1.05M tokens at once, about 1,572.9 pages of English text.

### Does the same text take the same number of tokens on Gemini 2.5 Pro and Gemini 3.5 Flash-Lite?

Yes, both are counted the same way: our lesson "How AI writes", 1,700 words long, is about 2,200 tokens on each.

### Is it cheaper to move from Gemini 2.5 Pro to Gemini 3.5 Flash-Lite?

Yes, per token: Gemini 3.5 Flash-Lite costs $0.30 per million tokens read and $2.50 written, against $1.25 and $10 on Gemini 2.5 Pro, which costs 4 times as much for the same tokens. Run your own tasks on it before you switch, since answers, length and thinking can differ.

### Can I pay less on Gemini 2.5 Pro and Gemini 3.5 Flash-Lite for work that can wait?

Not with a batch price: neither maker's price page lists one for these models. A cache still lowers the price of text the model reads again.

## Sources

- [Google: API prices](https://ai.google.dev/gemini-api/docs/pricing)
- [Epoch Capabilities Index, by Epoch AI (CC BY 4.0)](https://epoch.ai/benchmarks/eci)

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