Skip to main content
TC
TokenCost

Gemini 2.5 Flash vs Gemini 3.1 Flash-Lite

Complete pricing and performance comparison between Google's Gemini 2.5 Flash and Google's Gemini 3.1 Flash-Lite.

Quick Verdict

Cheaper
Gemini 3.1 Flash-Lite
1.2x cheaper input, 1.7x cheaper output
Larger Context
Gemini 2.5 Flash
1.0M vs 1.0M
Higher Quality
Gemini 3.1 Flash-Lite
Score: 34 vs 21
Faster
Gemini 2.5 Flash
231 vs 219 tok/s

Pricing Comparison

SpecGemini 2.5 FlashGemini 3.1 Flash-LiteDifference
ProviderGoogleGoogle
Input / 1M tokens$0.3$0.25Gemini 3.1 Flash-Lite is 17% more expensive
Output / 1M tokens$2.5$1.5Gemini 3.1 Flash-Lite is 40% more expensive
Context Window1.0M1.0MSame
Max Output66K66K

Performance Benchmarks

MetricGemini 2.5 FlashGemini 3.1 Flash-LiteWinner
Quality Index2134Gemini 3.1 Flash-Lite
Output Speed231 tok/s219 tok/sGemini 2.5 Flash
Time to First Token0.42s7.76sGemini 2.5 Flash
Value (Quality/$)68.7134.0Higher = 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).

UsageGemini 2.5 FlashGemini 3.1 Flash-LiteSavings
Single request
1K in / 300 out
$0.0010$0.0007Same
10 requests
10K in / 3K out
$0.010$0.0070Gemini 3.1 Flash-Lite saves $0.0035
100 requests
100K in / 30K out
$0.105$0.070Gemini 3.1 Flash-Lite saves $0.035
1,000 requests
1M in / 300K out
$1.05$0.700Gemini 3.1 Flash-Lite saves $0.350
10,000 requests
10M in / 3M out
$10.50$7.00Gemini 3.1 Flash-Lite saves $3.50
1M requests/mo
1B in / 300M out
$1050.00$700.00Gemini 3.1 Flash-Lite saves $350.00

Pros & Cons

Gemini 2.5 Flash Strengths

  • +Faster output (231 vs 219 tok/s)
  • +Lower latency (faster first token)

Gemini 3.1 Flash-Lite Strengths

  • +Cheaper input tokens
  • +Cheaper output tokens
  • +Higher quality score (34 vs 21)

When to Use Each Model

Choose Gemini 2.5 Flash for

  • →Real-time applications, chat, or autocomplete

Choose Gemini 3.1 Flash-Lite for

  • →Budget-conscious projects where cost is the primary factor
  • →Tasks requiring maximum accuracy and reasoning

Frequently Asked Questions

Which is cheaper, Gemini 2.5 Flash or Gemini 3.1 Flash-Lite?
For input tokens, Gemini 3.1 Flash-Lite is 1.2x cheaper at $0.25/1M tokens. For output tokens, Gemini 3.1 Flash-Lite is 1.7x cheaper at $1.5/1M tokens. At typical usage (1M input + 300K output), Gemini 2.5 Flash costs $1.05 vs Gemini 3.1 Flash-Lite at $0.700.
What's the context window difference?
Gemini 2.5 Flash supports 1.0M context (1,048,576 tokens), while Gemini 3.1 Flash-Lite supports 1.0M (1,048,576 tokens). Gemini 3.1 Flash-Lite can handle 1x more context in a single request.
Which model has better benchmarks?
Quality Index: Gemini 2.5 Flash scores 21 vs Gemini 3.1 Flash-Lite at 34. Speed: Gemini 2.5 Flash generates 231 tok/s vs Gemini 3.1 Flash-Lite at 219 tok/s. Time to first token: Gemini 2.5 Flash at 0.42s vs Gemini 3.1 Flash-Lite at 7.76s.
When should I choose Gemini 2.5 Flash over Gemini 3.1 Flash-Lite?
Choose Gemini 2.5 Flash when you need: Faster output (231 vs 219 tok/s), Lower latency (faster first token). Choose Gemini 3.1 Flash-Lite when you need: Cheaper input tokens, Cheaper output tokens, Higher quality score (34 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 3.1 Flash-Lite = $7.00. At 10K input + 1K output per request (longer conversations): Gemini 2.5 Flash = $55.00, Gemini 3.1 Flash-Lite = $40.00.

Related Comparisons

Gemini 3.1 Flash-Lite vs GPT-5.4
$0.25 vs $2.5 per 1M input
Gemini 2.5 Flash vs GPT-5.4
$0.3 vs $2.5 per 1M input
Gemini 3.1 Flash-Lite vs GPT-5.4 Mini
$0.25 vs $0.75 per 1M input
Gemini 2.5 Flash vs GPT-5.4 Mini
$0.3 vs $0.75 per 1M input
Gemini 3.1 Flash-Lite vs GPT-5.4 Nano
$0.25 vs $0.2 per 1M input
Gemini 2.5 Flash vs GPT-5.4 Nano
$0.3 vs $0.2 per 1M input
Gemini 2.5 Flash DetailsGemini 3.1 Flash-Lite DetailsFull Pricing TableCost Calculator