Gemini 2.5 has three stable options. Pro focuses on deep reasoning and accuracy. Flash gives the best balance of quality, latency, and cost. Flash Lite maximizes throughput and savings for very large volumes.
TLDR
- Gemini 2.5 Pro: Choose for complex briefs, technical topics, and high risk content where correctness matters most.
- Gemini 2.5 Flash: Choose for most product and content workflows where you want strong quality with low latency and sensible cost.
- Gemini 2.5 Flash Lite: Choose for bulk generation, translations, and programmatic SEO at scale when cost and speed matter more than the last few points of quality.
What changed since the 1.x era
| Feature | Details |
|---|---|
| Input Types | All three accept text, images, video, and audio as input. Output is text. |
| Context Window | All three offer about 1,048,576 input tokens and about 65,536 output tokens. |
| Thinking Capability | Thinking is part of the models. You can set a thinking budget on Flash and Flash Lite. Pro thinks by default. |
| Migration Notice | 1.5 models are marked deprecated in the Gemini API. Plan a migration to 2.5. |
Modality and context
| Model | Inputs | Output | Input context | Output limit | Good to know |
|---|---|---|---|---|---|
| 2.5 Pro | Text, images, video, audio, PDF | Text | 1,048,576 tokens | 65,536 | Best reasoning and coding. Supports function calling, code execution, Search Grounding, caching. |
| 2.5 Flash | Text, images, video, audio | Text | 1,048,576 | 65,536 | Great price performance and latency. Thinking budget available. |
| 2.5 Flash Lite | Text, images, video, audio, PDF | Text | 1,048,576 | 65,536 | Most cost efficient. Built for high throughput and real time use. |
Features at a glance
- Thinking controls: Help you trade accuracy for cost and latency when needed.
- Tools: Function calling, code execution, Search Grounding, and caching across the family.
- Batch mode: Cuts cost for large jobs.
Pricing in USD per 1M tokens
Standard API
| Model | Input text image video | Input audio | Output |
|---|---|---|---|
| 2.5 Pro | $1.25 up to 200k tokens, $2.50 above | — | $10.00 up to 200k, $15.00 above |
| 2.5 Flash | $0.30 | $1.00 | $2.50 |
| 2.5 Flash Lite | $0.10 | $0.30 | $0.40 |
Search Grounding on paid tier is free up to about 1,500 requests per day and then about $35 per 1,000 requests. Context caching storage is about $4.50 per 1M tokens per hour for Pro and about $1.00 for Flash and Flash Lite in Standard mode.
Batch API
| Model | Input text image video | Input audio | Output |
|---|---|---|---|
| 2.5 Pro | $0.625 up to 200k, $1.25 above | — | $5.00 up to 200k, $7.50 above |
| 2.5 Flash | $0.15 | $0.50 | $1.25 |
| 2.5 Flash Lite | $0.05 | $0.15 | $0.20 |
Batch Search Grounding over the free allowance is about $17.50 per 1,000 grounded requests. Batch caching storage is about $2.25 per 1M tokens per hour for Pro and about $0.50 for Flash and Flash Lite.
Migration notes from 1.5 and 1.0
- Start with 2.5 Flash: Move first to 2.5 Flash as a safe default. Promote critical flows to Pro.
- Thinking budgets: Set thinking budgets by use case. Higher for fact dense drafts. Lower or zero for bulk metadata.
- Context caching: Use context caching for brand voice, product catalogs, and style guides to cut cost.
Verdict
| Model | Best For |
|---|---|
| 2.5 Pro | Correctness first work |
| 2.5 Flash | Most day to day product and content tasks |
| 2.5 Flash Lite | Massive scale and near real time experiences |
Frequently Asked Questions
What's the main difference between Gemini 2.5 Pro, Flash, and Flash Lite?
Pro prioritizes accuracy and reasoning for complex tasks. Flash balances quality, speed, and cost for general use. Flash Lite maximizes speed and cost efficiency for high-volume, simple tasks.
When should I adjust the thinking budget?
Increase the budget for complex reasoning and high stakes drafts. Reduce or disable it for bulk metadata and simple rewrites where speed and cost matter more.
Which model should I use for programmatic SEO at scale?
Use Flash Lite with Batch for the lowest cost and highest throughput. Use Flash when you need a bit more quality without a large cost jump. Promote to Pro only for flows where accuracy directly saves human editing time.