Gemini 2.5 Flash vs Gemini 3.5 Flash — Side-by-side pricing
Side-by-side API pricing and tokenizer details for Gemini 2.5 Flash (Google) and Gemini 3.5 Flash (Google).
Side-by-side pricing
| Feature | Gemini 2.5 Flash | Gemini 3.5 Flash |
|---|---|---|
| Provider | ||
| Input (per 1M tokens) | $0.300 | $1.50 |
| Output (per 1M tokens) | $2.50 | $9.00 |
| Context caching | Yes — 90% off cached tokens | Yes — 90% off cached tokens |
| Batch API discount | 50% off | 50% off |
| Context window | 1M tokens | 1M tokens |
| Tokenizer | Gemini tokenizer | Gemini tokenizer |
Real-world cost example
1,000 API requests per month, each with 500 input tokens and 200 output tokens (500K input + 200K output total).
Gemini 2.5 Flash
$0.6500
Input: $0.1500 +Output: $0.5000
Gemini 3.5 Flash
$2.5500
Input: $0.7500 +Output: $1.8000
Gemini 2.5 Flash is 75% cheaper for this workload — saving $1.9000 per month at this volume.
Frequently asked questions
Yes, Gemini 2.5 Flash is cheaper for the typical workload above. At $0.300/1M input and $2.50/1M output tokens, it costs $0.6500 versus $2.5500 for Gemini 3.5 Flash — a 75% difference. Costs scale linearly with request volume, so larger workloads amplify this gap.
Gemini 2.5 Flash supports a 1M token context window. Gemini 3.5 Flash supports a 1M token context window. A larger context window lets you include more text — documents, conversation history, or code — in a single API call.
Gemini 2.5 Flash supports context caching (90% off repeated tokens). It offers a 50% Batch API discount. Gemini 3.5 Flash supports context caching (90% off repeated tokens). It offers a 50% Batch API discount.
Yes, both Gemini 2.5 Flash and Gemini 3.5 Flash use the Gemini tokenizer. The same text produces identical token counts on both models, so any cost difference is purely due to the rate each provider charges per token.
Gemini 2.5 Flash (Google): $0.3 input / $2.5 output per 1M tokens. Gemini 3.5 Flash (Google): $1.5 input / $9 output per 1M tokens. Rates shown before caching or batch discounts.
For an 80% output / 20% input workload — typical for code generation or long-form writing — Gemini 2.5 Flash costs $2.0600 per 1M total tokens and Gemini 3.5 Flash costs $7.5000. Gemini 2.5 Flash is 73% cheaper for this pattern. For your exact ratio, paste a real prompt into the calculator above.
Gemini 2.5 Flash has a 1M-token context window — approximately 750K words or ~3K pages of standard text. Gemini 3.5 Flash has a 1M-token context window — approximately 750K words or ~3K pages. (Estimates assume ~0.75 words per token.)
Calculate costs for your actual prompt
Paste your prompt into the calculator and get exact token counts using each model's real tokenizer — all in your browser.
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