Gemini 2.5 Flash vs Gemini 3 Flash
Complete pricing and performance comparison between Google's Gemini 2.5 Flash and Google's Gemini 3 Flash.
Quick Verdict
Cheaper
Gemini 2.5 Flash
1.7x cheaper input, 1.2x cheaper output
Larger Context
Gemini 2.5 Flash
1.0M vs 1.0M
Higher Quality
Gemini 3 Flash
Score: 35 vs 21
Faster
Gemini 2.5 Flash
231 vs 192 tok/s
Pricing Comparison
| Spec | Gemini 2.5 Flash | Gemini 3 Flash | Difference |
|---|---|---|---|
| Provider | |||
| Input / 1M tokens | $0.3 | $0.5 | Gemini 2.5 Flash is 40% more expensive |
| Output / 1M tokens | $2.5 | $3 | Gemini 2.5 Flash is 17% more expensive |
| Context Window | 1.0M | 1.0M | Same |
| Max Output | 66K | 66K |
Performance Benchmarks
| Metric | Gemini 2.5 Flash | Gemini 3 Flash | Winner |
|---|---|---|---|
| Quality Index | 21 | 35 | Gemini 3 Flash |
| Output Speed | 231 tok/s | 192 tok/s | Gemini 2.5 Flash |
| Time to First Token | 0.42s | 1.28s | Gemini 2.5 Flash |
| Value (Quality/$) | 68.7 | 70.0 | Higher = better value |
Benchmark data from Artificial Analysis. Quality Index is a composite score across reasoning, coding, and knowledge tasks.
Cost at Scale
Estimated cost at different usage levels (3:1 input-to-output token ratio, typical for chat).
| Usage | Gemini 2.5 Flash | Gemini 3 Flash | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0010 | $0.0014 | Same |
10 requests 10K in / 3K out | $0.010 | $0.014 | Gemini 2.5 Flash saves $0.0035 |
100 requests 100K in / 30K out | $0.105 | $0.140 | Gemini 2.5 Flash saves $0.035 |
1,000 requests 1M in / 300K out | $1.05 | $1.40 | Gemini 2.5 Flash saves $0.350 |
10,000 requests 10M in / 3M out | $10.50 | $14.00 | Gemini 2.5 Flash saves $3.50 |
1M requests/mo 1B in / 300M out | $1050.00 | $1400.00 | Gemini 2.5 Flash saves $350.00 |
Pros & Cons
Gemini 2.5 Flash Strengths
- +Cheaper input tokens
- +Cheaper output tokens
- +Faster output (231 vs 192 tok/s)
- +Lower latency (faster first token)
Gemini 3 Flash Strengths
- +Higher quality score (35 vs 21)
When to Use Each Model
Choose Gemini 2.5 Flash for
- →Budget-conscious projects where cost is the primary factor
- →Real-time applications, chat, or autocomplete
Choose Gemini 3 Flash for
- →Tasks requiring maximum accuracy and reasoning
Frequently Asked Questions
Which is cheaper, Gemini 2.5 Flash or Gemini 3 Flash?
For input tokens, Gemini 2.5 Flash is 1.7x cheaper at $0.3/1M tokens. For output tokens, Gemini 2.5 Flash is 1.2x cheaper at $2.5/1M tokens. At typical usage (1M input + 300K output), Gemini 2.5 Flash costs $1.05 vs Gemini 3 Flash at $1.40.
What's the context window difference?
Gemini 2.5 Flash supports 1.0M context (1,048,576 tokens), while Gemini 3 Flash supports 1.0M (1,048,576 tokens). Gemini 3 Flash can handle 1x more context in a single request.
Which model has better benchmarks?
Quality Index: Gemini 2.5 Flash scores 21 vs Gemini 3 Flash at 35. Speed: Gemini 2.5 Flash generates 231 tok/s vs Gemini 3 Flash at 192 tok/s. Time to first token: Gemini 2.5 Flash at 0.42s vs Gemini 3 Flash at 1.28s.
When should I choose Gemini 2.5 Flash over Gemini 3 Flash?
Choose Gemini 2.5 Flash when you need: Cheaper input tokens, Cheaper output tokens, Faster output (231 vs 192 tok/s), Lower latency (faster first token). Choose Gemini 3 Flash when you need: Higher quality score (35 vs 21).
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): Gemini 2.5 Flash = $10.50, Gemini 3 Flash = $14.00. At 10K input + 1K output per request (longer conversations): Gemini 2.5 Flash = $55.00, Gemini 3 Flash = $80.00.
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