Gemini 3.1 Flash Lite vs GPT-5.1 Codex
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
Gemini 3.1 Flash Lite by Google wins on 5 of 7 benchmarks against GPT-5.1 Codex by OpenAI, which leads on 2. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
Coding: In coding, GPT-5.1 Codex scores 1197 on Design Arena ELO compared to Gemini 3.1 Flash Lite's 1090, while GPT-5.1 Codex scores 1174 on Website Arena ELO compared to Gemini 3.1 Flash Lite's 1095.
Reasoning: In reasoning, Gemini 3.1 Flash Lite scores 80.1% on GPQA Diamond compared to GPT-5.1 Codex's 65.0%.
Context: In context, Gemini 3.1 Flash Lite scores 1.0M on Context Length compared to GPT-5.1 Codex's 400K.
Pricing Comparison
Gemini 3.1 Flash Lite costs $0.25/1M input tokens and $1.5/1M output tokens, while GPT-5.1 Codex costs $1.3/1M input and $10.0/1M output. Gemini 3.1 Flash Lite is the more affordable option for API usage.
Verdict
Gemini 3.1 Flash Lite leads across the board in affordability, making it the stronger overall choice in this comparison.
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Gemini 3.1 Flash Lite vs GPT-5.1 Codex — FAQ
Which is better, Gemini 3.1 Flash Lite or GPT-5.1 Codex?
Gemini 3.1 Flash Lite wins on more benchmarks overall (5 vs 2). However, the best choice depends on your specific needs — each model excels in different areas.
How does Gemini 3.1 Flash Lite compare to GPT-5.1 Codex for coding?
SWE-bench Verified data is not available for both models. Check the detailed comparison charts above for other coding-related metrics.
Is Gemini 3.1 Flash Lite cheaper than GPT-5.1 Codex?
Yes, Gemini 3.1 Flash Lite is cheaper. Gemini 3.1 Flash Lite costs $0.25/1M input and $1.5/1M output tokens. GPT-5.1 Codex costs $1.3/1M input and $10.0/1M output tokens.
Which is faster, Gemini 3.1 Flash Lite or GPT-5.1 Codex?
Output speed data is not available for both models. Check the speed section of the comparison above for available performance data.
What benchmarks does the Gemini 3.1 Flash Lite vs GPT-5.1 Codex comparison cover?
This comparison covers 7 benchmarks including GPQA Diamond, Input Cost, Output Cost, Context Length, Cached Input Cost, Design Arena ELO, Website Arena ELO. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.