Last verified 2025-09-22 (left) · 2025-09-22 (right)
Gemini 2.5 Flash vs o3 — Pricing & Capability Comparison
Gemini 2.5 Flash charges $0.30 per million input tokens and $2.50 per million output tokens. o3 comes in at $2.00 / $8.00. Context windows span 1M vs 200K tokens respectively.
TL;DR — Quick Comparison
- ✓Gemini 2.5 Flash is cheaper overall: $2.80 per 1M tokens (in+out) vs $10.00 for o3 — saves $7.20 per 1M tokens
- ✓Input pricing: Gemini 2.5 Flash $0.30/1M vs o3 $2.00/1M
- ✓Output pricing: Gemini 2.5 Flash $2.50/1M vs o3 $8.00/1M
- ✓Context window: Gemini 2.5 Flash offers more (1M vs 200K)
- ✓Use our calculator below to estimate costs for your specific usage pattern
Input price (per 1M)
Gemini 2.5 Flash
$0.30
o3
$2.00
Gemini 2.5 Flash leads here
Output price (per 1M)
Gemini 2.5 Flash
$2.50
o3
$8.00
Gemini 2.5 Flash leads here
Context window
Gemini 2.5 Flash
1,000,000 tokens
o3
200,000 tokens
Gemini 2.5 Flash leads here
Cached input
Gemini 2.5 Flash
Not published
o3
Not published
No published data
Cost comparison for 10K-token workloads
Side-by-side pricing for identical workloads (10,000 total tokens per request) across different distributions.
| Scenario | Gemini 2.5 Flash | o3 |
|---|---|---|
Balanced conversation 50% input · 50% output | $0.0140 | $0.0500 |
Input-heavy workflow 80% input · 20% output | $0.0074 | $0.0320 |
Generation heavy 30% input · 70% output | $0.0184 | $0.0620 |
Cached system prompt 90% cached input · 10% fresh output | $0.0052 | $0.0260 |
Frequently asked questions
Which is cheaper: Gemini 2.5 Flash or o3?
Gemini 2.5 Flash is cheaper for input tokens at $0.30 per 1M tokens compared to $2.00. For output, Gemini 2.5 Flash costs $2.50 per 1M tokens versus $8.00 for o3.
What is the cost per 1M tokens for Gemini 2.5 Flash?
Gemini 2.5 Flash pricing: $0.30 per 1M input tokens and $2.50 per 1M output tokens. Context window: 1,000,000 tokens.
What is the cost per 1M tokens for o3?
o3 pricing: $2.00 per 1M input tokens and $8.00 per 1M output tokens. Context window: 200,000 tokens.
How much does it cost per 1K tokens?
Per 1K tokens: Gemini 2.5 Flash costs $0.0003 input / $0.0025 output. o3 costs $0.0020 input / $0.0080 output. This is useful for calculating small-scale usage costs.
Which model supports a larger context window?
Gemini 2.5 Flash offers 1,000,000 tokens (1M) versus 200K for o3.
What is the estimated monthly cost for typical usage?
For a typical workload of 10M input + 2M output tokens per month: Gemini 2.5 Flash would cost approximately $8.00, while o3 would cost $36.00. Gemini 2.5 Flash is more economical for this usage pattern.
Do these models support prompt caching?
Gemini 2.5 Flash does not publish cached pricing. o3 does not publish cached pricing.
Which model is best for my use case?
Choose Gemini 2.5 Flash for cost-sensitive applications with high input volume. Choose Gemini 2.5 Flash if you need 1M context for long documents or conversations. Consider prompt caching if you have repeated context. Use our token calculator to model your specific usage pattern.