o3 vs Gemini 2.5 Pro: Detailed Comparison
Choosing between o3 (OpenAI) and
Gemini 2.5 Pro (Google) comes down to three things:
per-token pricing, context window, and which capability matters most for your workload.
o3 costs $2.00/M input vs
$1.25/M for Gemini 2.5 Pro;
context windows are 200K vs
2.0M tokens. Detailed breakdown below.
Side-by-side specs
| Spec | o3 | Gemini 2.5 Pro |
|---|
| Provider | OpenAI | Google |
|---|
| Released | 2025-04-16 | 2025-03-25 |
|---|
| Input price |
$2.00/M |
$1.25/M |
| Output price |
$8.00/M |
$10.00/M |
| Cached input |
$0.5000/M |
$0.3100/M |
| Context window |
200K |
2.0M |
| Max output |
100K |
66K |
| Modalities |
text image |
text image audio video |
| Tokenizer |
o200k_base |
gemini |
Capability matrix
| Capability | o3 | Gemini 2.5 Pro |
|---|
| function calling |
Yes |
Yes |
| json mode |
Yes |
Yes |
| vision |
Yes |
Yes |
| reasoning |
Yes |
No |
| streaming |
No |
Yes |
| audio |
No |
Yes |
| video |
No |
Yes |
| thinking |
No |
Yes |
Benchmark comparison
Higher is better for all benchmarks shown.
Per-call cost on typical workloads
| Workload (in/out tokens) | o3 | Gemini 2.5 Pro | Cheaper by |
|---|
| Standard chat (1K / 500) |
$0.006000 |
$0.006250 |
o3 by $0.000250 |
| RAG (4K / 500) |
$0.012000 |
$0.010000 |
Gemini 2.5 Pro by $0.002000 |
| Long doc (20K / 1K) |
$0.048000 |
$0.035000 |
Gemini 2.5 Pro by $0.013000 |
| Very long context (100K / 2K) |
$0.212000 |
$0.140000 |
Gemini 2.5 Pro by $0.072000 |
When to choose o3 over Gemini 2.5 Pro
- Supports reasoning — Gemini 2.5 Pro does not.
When to choose Gemini 2.5 Pro over o3
- Per-token input cost is 38% lower than o3.
- Larger context window (2.0M vs 200K).
- Supports streaming — o3 does not.
- Supports audio — o3 does not.
- Supports video — o3 does not.
- Supports thinking — o3 does not.
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