GPTvsGemini

GPT 5.1 vs Gemini 2.5 Flash-Lite

Side-by-side comparison of pricing, task quality, and projected cost at higher scale.

Pricing

Side-by-side pricing

GPT 5.1

Mid-tier

Gemini 2.5 Flash-Lite

Fast / Budget
Input $/MTok
$1.25
$0.10
Output $/MTok
$10.00
$0.40
Cache discount
90% off
90% off
Context
272K
1,048.576K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
0
vs
0
Code Review
0
vs
0
Summarization
0
vs
0
Q&A
0
vs
0
Extraction
0
vs
0
Reasoning
0
vs
0
Classification
0
vs
0
Creative Writing
0
vs
0
GPT 5.1
Gemini 2.5 Flash-Lite

Guidance

When to use GPT 5.1 vs Gemini 2.5 Flash-Lite

Choose GPT 5.1 when...

  • Similar performance; consider provider preference or ecosystem fit.

Choose Gemini 2.5 Flash-Lite when...

  • -Cost matters: 92% cheaper on input tokens
  • -You need a larger context window (1,048.576K vs 272K)

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5.1
Gemini 2.5 Flash-Lite
100K tokens
$0.39
$0.02Cheaper
1M tokens
$3.88
$0.19Cheaper
10M tokens
$38.75
$1.90Cheaper

FAQ

When should I use GPT 5.1 instead of Gemini 2.5 Flash-Lite?

GPT 5.1 and Gemini 2.5 Flash-Lite perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is Gemini 2.5 Flash-Lite cheaper than GPT 5.1?

Yes. Gemini 2.5 Flash-Lite input costs $0.10/MTok vs $1.25/MTok for GPT 5.1, saving 92% on input.

What are the context window sizes for GPT 5.1 and Gemini 2.5 Flash-Lite?

GPT 5.1 has a 272K token context window. Gemini 2.5 Flash-Lite has a 1,048.576K token context window.

Track your real costs

Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.