Comparison · Google and OpenAI
Gemini 3.8 Flash vs GPT-5.4 Mini
Listed API prices of Gemini 3.8 Flash and GPT-5.4 Mini turned into the cost of the same three standard tasks, with speed from our own test requests in the United States and what each provider’s API documentation says about features that break on a switch. Output quality and answer length are not compared.
Calculated impact cost per task and per month
For an L2 task (deep analysis over a 50,000-token document, 3 steps), Gemini 3.8 Flash costs $0.131 and GPT-5.4 Mini $0.133 at the prices listed in the United States on , so Gemini 3.8 Flash is 1.7 % less than GPT-5.4 Mini, counting visible output only, without cache discounts or hidden reasoning.
| Task | Gemini 3.8 Flash, per task | GPT-5.4 Mini, per task | Gemini 3.8 Flash, per month | GPT-5.4 Mini, per month | Gemini 3.8 Flash vs GPT-5.4 Mini, per task |
|---|---|---|---|---|---|
| L1Micro-task (classification or strict JSON extraction) | $0.0019per L1 task | $0.0020per L1 task | $27.38per month | $29.57per month | −7.4 % |
| L2Deep analysis over a 50,000-token document | $0.131per L2 task | $0.133per L2 task | $1,905.30per month | $1,938.15per month | −1.7 % |
| L3Agentic coding loop, 15 steps | $1.02per L3 task | $1.03per L3 task | $14,897.47per month | $14,996.02per month | −0.7 % |
Calculated Per month: 20 tasks an hour around the clock, 730 hours.
Prices USD per 1M tokens
| Price | Gemini 3.8 Flash | GPT-5.4 Mini |
|---|---|---|
| Input, per 1M tokens | $0.750 | $0.750 |
| Output, per 1M tokens | $3.75 | $4.50 |
| Price from | Provider's price list · source page Published | Provider's price list · source page Published |
| Read | · the United States | · the United States |
| Context window | 1,048,576 tokens | 400,000 tokens |
What can I use it for? six common tasks, our data checks
Quality on your task: not measured by Measured Lab yet.
| Task | Gemini 3.8 Flash | GPT-5.4 Mini |
|---|---|---|
| Answer customer messages | Fits on price and context | Fits on price and context |
| Pull data from invoices and documents with strict JSON and page images | Fits on price and context | Fits on price and context |
| Summarize documents and meetings | Fits on price and context | Fits on price and context |
| Translate content | Fits on price and context | Fits on price and context |
| Chat assistant on your website | Fits on price and context | Fits on price and context |
| Write and review code with tool calls | Fits on price and context | Fits on price and context |
| Tasks it fits | 6 of 6 | 6 of 6 |
Checks of our data for six common tasks: a published price, a context window and answer length for the task and, where the task needs them, strict JSON output, page images and tool calls; prices, cost a month and terms for each model on its model card. Compare models for your own task in the model picker.
Speed in the US Observed our test requests
In our test requests from the United States, the median time to the first answer token was 6,955 ms for Gemini 3.8 Flash (Direct API · Google) and 663 ms for GPT-5.4 Mini (Direct API · OpenAI).
| Model and route | Time to first answer token, median | Output speed, median | Answers |
|---|---|---|---|
| Gemini 3.8 FlashDirect API · Google | 6,955 ms range 1,021 ms–10,510 ms | 200 tokens/s range 103 tokens/s–365 tokens/s | 95 answers on 19 dates |
| GPT-5.4 MiniDirect API · OpenAI | 663 ms range 319 ms–30,568 ms | 156 tokens/s range 47.6 tokens/s–265 tokens/s | 120 answers on 23 dates |
The same short request to every model, sent from a measurement point in the United States; medians of successful answers on at least 2 different dates, latest on . How we measure
What breaks when you switch Published provider documentation
Moving from Google to OpenAI: every feature that Google’s documentation lists as supported is also listed as supported by OpenAI.
Moving from OpenAI to Google, 1 of the 5 features may not carry over, by each provider’s documentation:
- Cache covers tool definitions — OpenAI: yes; Google: not stated. Where the cache does not cover tool definitions, a long tool list is paid as fresh input on every request.
| Feature of the API | OpenAI | |
|---|---|---|
| Strict JSON schemas | Yes | Yes |
| Parallel tool calls | Yes | Yes |
| Streamed tool arguments | Yes | Yes |
| Reasoning with tools | Yes | Yes |
| Cache covers tool definitions | Not stated | Yes |
What each provider’s own API documentation says, read ; “not stated” is not the same as “no”. Quotes and sources: what breaks when you switch AI APIs.