Model Comparison
Gemini 2.5 Flash vs Gemini 3.1 Flash-LiteWhich is better in 2026?
Gemini 3.1 Flash-Lite shows notably better performance in the majority of benchmarks. Gemini 3.1 Flash-Lite is 1.5x cheaper per token.
Verdict: Gemini 2.5 Flash vs Gemini 3.1 Flash-Lite — which is better?
Gemini 2.5 Flash (by Google) and Gemini 3.1 Flash-Lite (by Google) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Gemini 2.5 Flash outperforms in 1 benchmarks (FACTS Grounding), while Gemini 3.1 Flash-Lite is better at 3 benchmarks (GPQA, Humanity's Last Exam, SimpleQA). Gemini 3.1 Flash-Lite shows notably better performance in the majority of benchmarks.
On price, Gemini 3.1 Flash-Lite is roughly 1.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Gemini 2.5 Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Gemini 2.5 Flash if…
- you process long inputs — it offers a 1,048,576 token context window
Choose Gemini 3.1 Flash-Lite if…
- you want the strongest raw capability — it leads on 3 of 4 shared benchmarks
- cost matters — it's about 1.5x cheaper per token
- you want the most recent training data — it shipped Mar 2026
Performance Benchmarks
Comparative analysis across standard metrics
Gemini 2.5 Flash outperforms in 1 benchmarks (FACTS Grounding), while Gemini 3.1 Flash-Lite is better at 3 benchmarks (GPQA, Humanity's Last Exam, SimpleQA).
Gemini 3.1 Flash-Lite shows notably better performance in the majority of benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 2.5 Flash ($0.30/1M tokens) is 1.2x more expensive than Gemini 3.1 Flash-Lite ($0.25/1M tokens).
For output processing, Gemini 2.5 Flash ($2.50/1M tokens) is 1.7x more expensive than Gemini 3.1 Flash-Lite ($1.50/1M tokens).
In conclusion, Gemini 2.5 Flash is more expensive than Gemini 3.1 Flash-Lite.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 2.5 Flash accepts 1,048,576 input tokens compared to Gemini 3.1 Flash-Lite's 1,000,000 tokens. Both models can generate responses up to 65,536 tokens.
Input Capabilities
Supported data types and modalities
Both Gemini 2.5 Flash and Gemini 3.1 Flash-Lite support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 2.5 Flash
Gemini 3.1 Flash-Lite
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Gemini 2.5 Flash was released on 2025-05-20, while Gemini 3.1 Flash-Lite was released on 2026-03-03.
Gemini 3.1 Flash-Lite is 10 months newer than Gemini 2.5 Flash.
May 20, 2025
1.2 years ago
Mar 3, 2026
4 months ago
9mo newerKnowledge Cutoff
When training data ends
Both models have the same knowledge cutoff date of 2025-01-31.
They should have similar awareness of historical events and information up to this date.
Jan 2025
Jan 2025
Provider Availability
Gemini 2.5 Flash is available from Google. Gemini 3.1 Flash-Lite is available from Google.
Gemini 2.5 Flash
Gemini 3.1 Flash-Lite
Outputs Comparison
Key Takeaways
Gemini 2.5 FlashGemini 3.1 Flash-LiteDetailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Gemini 2.5 Flash and Gemini 3.1 Flash-Lite side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Gemini 2.5 Flash vs Gemini 3.1 Flash-Lite.