Gemini 2.5 Flash vs GPT-4o Mini: Detailed Comparison
Choosing between Gemini 2.5 Flash (Google) and
GPT-4o Mini (OpenAI) comes down to three things:
per-token pricing, context window, and which capability matters most for your workload.
Gemini 2.5 Flash costs $0.30/M input vs
$0.15/M for GPT-4o Mini;
context windows are 1.0M vs
128K tokens. Detailed breakdown below.
Side-by-side specs
| Spec | Gemini 2.5 Flash | GPT-4o Mini |
|---|
| Provider | Google | OpenAI |
|---|
| Released | 2025-04-09 | 2024-07-18 |
|---|
| Input price |
$0.30/M |
$0.15/M |
| Output price |
$2.50/M |
$0.60/M |
| Cached input |
$0.0750/M |
$0.0750/M |
| Context window |
1.0M |
128K |
| Max output |
66K |
16K |
| Modalities |
text image audio video |
text image |
| Tokenizer |
gemini |
o200k_base |
Capability matrix
| Capability | Gemini 2.5 Flash | GPT-4o Mini |
|---|
| function calling |
Yes |
Yes |
| json mode |
Yes |
Yes |
| vision |
Yes |
Yes |
| streaming |
Yes |
Yes |
| audio |
Yes |
No |
| video |
Yes |
No |
Per-call cost on typical workloads
| Workload (in/out tokens) | Gemini 2.5 Flash | GPT-4o Mini | Cheaper by |
|---|
| Standard chat (1K / 500) |
$0.001550 |
$0.000450 |
GPT-4o Mini by $0.001100 |
| RAG (4K / 500) |
$0.002450 |
$0.000900 |
GPT-4o Mini by $0.001550 |
| Long doc (20K / 1K) |
$0.008500 |
$0.003600 |
GPT-4o Mini by $0.004900 |
| Very long context (100K / 2K) |
$0.033750 |
$0.015900 |
GPT-4o Mini by $0.017850 |
When to choose Gemini 2.5 Flash over GPT-4o Mini
- Larger context window (1.0M vs 128K) — relevant when whole documents or long histories must fit in a single call.
- Supports audio — GPT-4o Mini does not.
- Supports video — GPT-4o Mini does not.
When to choose GPT-4o Mini over Gemini 2.5 Flash
- Per-token input cost is 50% lower than Gemini 2.5 Flash.
Related comparisons