# Gemini 2.5 Flash vs GPT-4o mini

GPT-4o mini is the cheaper of the 2: for the same tokens, 3 read for each 1 written, Gemini 2.5 Flash costs 3.2 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-flash-vs-gpt-4o-mini
- Makers: Gemini 2.5 Flash from Google, GPT-4o mini from OpenAI

## Price per million tokens, in US dollars

| | Gemini 2.5 Flash | GPT-4o mini |
| --- | --: | --: |
| Input | $0.30 | $0.15 |
| Cached input | $0.03 | $0.075 |
| Cache write | not listed | not listed |
| Output | $2.50 | $0.60 |
| Blend, 3 read for each 1 written | $0.85 | $0.2625 |
| Batch input | not listed | $0.075 |
| Batch output | not listed | $0.30 |
| Context window, tokens | 1.05M | 128K |
| Capability score (Epoch Capabilities Index; GPT-5 is 150) | not listed | 127 |
| Longest answer, tokens | 66K | 16K |

Gemini 2.5 Flash: Audio input is $1.

## The same text, counted by each maker

Our lesson "How AI writes" (https://tecyfy.com/learn/how-ai-works/how-ai-writes), about 1,700 words of English:

- Gemini 2.5 Flash: about 2,200 tokens. Google does not publish the Gemini tokenizer. Its rule is that a token is about 4 characters, so the count is the characters divided by 4.
- GPT-4o mini: about 2,100 tokens. GPT-5.6 is counted with o200k_base, the tokenizer OpenAI publishes for it, so its count is exact. OpenAI has not published the tokenizer of GPT-6, so its count is the same o200k_base figure, marked as about.

## 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 Flash | GPT-4o mini |
| --- | --- | --: | --: |
| A chat question | 300, 500, 100 | $4.02 | $1.04 |
| A hard question, with thinking | 300, 1,400, 100 | $10.77 | $2.66 |
| A long report, summarised | 60,000, 2,000, 20 | $13.80 | $6.12 |
| A 40-turn agent task | 2,800,000, 40,000, 10 | $77.88 | too long for its window |
| A support bot's reply | 4,000, 300, 2,000 | $84.60 | $37.80 |
| Sort a message into a category | 250, 5, 50,000 | $131 | $60.75 |
| Read an invoice into fields | 1,500, 250, 1,000 | $32.25 | $11.25 |
| Review a pull request | 25,000, 4,500, 50 | $28.13 | $9.67 |

## Questions

### Which is cheaper, Gemini 2.5 Flash or GPT-4o mini?

GPT-4o mini is cheaper: $0.15 per million tokens read and $0.60 per million written, against $0.30 and $2.50 on Gemini 2.5 Flash. On a mix of 3 tokens read for each 1 written, Gemini 2.5 Flash costs 3.2 times as much.

### Which is better, Gemini 2.5 Flash or GPT-4o mini?

GPT-4o mini scores 127 on the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks (GPT-5 is 150). Gemini 2.5 Flash 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 Flash and GPT-4o mini?

At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $84.60 a month on Gemini 2.5 Flash and $37.80 on GPT-4o mini: Gemini 2.5 Flash costs 2.2 times as much for this job.

### Which has the larger context window, Gemini 2.5 Flash or GPT-4o mini?

Gemini 2.5 Flash, with 1.05M tokens against 128K on GPT-4o mini. The window holds your instructions, the files you attach, the conversation so far and the answer, all at once.

### Does the same text take the same number of tokens on Gemini 2.5 Flash and GPT-4o mini?

No. Our lesson "How AI writes", 1,700 words long, is about 2,200 tokens on Gemini 2.5 Flash and about 2,100 on GPT-4o mini. Each maker cuts text its own way, and every extra token is paid for at the model's price.

### Can I pay less on Gemini 2.5 Flash and GPT-4o mini for work that can wait?

On GPT-4o mini only: with a batch, where you collect the answers later, it costs $0.075 per million tokens read and $0.30 written. Google's price page lists no batch price for Gemini 2.5 Flash.

## Sources

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

## Other comparisons

- [GPT-4o mini vs GPT-6 Astra](https://tecyfy.com/prices/compare/gpt-4o-mini-vs-gpt-6-astra.md)
- [GPT-4o mini vs GPT-6.1 Sol](https://tecyfy.com/prices/compare/gpt-4o-mini-vs-gpt-6-1-sol.md)
- [GPT-4o mini vs GPT-6 Luna](https://tecyfy.com/prices/compare/gpt-4o-mini-vs-gpt-6-luna.md)
- [Gemini 2.5 Flash vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-2-5-flash-vs-gemini-4-argon.md)
- [Gemini 2.5 Flash vs Gemini 3.8 Flash](https://tecyfy.com/prices/compare/gemini-2-5-flash-vs-gemini-3-8-flash.md)
- [Gemini 2.5 Flash vs Gemini 3.5 Flash-Lite](https://tecyfy.com/prices/compare/gemini-2-5-flash-vs-gemini-3-5-flash-lite.md)