o3-mini vs Gemini 3.1 Flash-Lite

Side-by-side benchmark comparison across knowledge, coding, math, and reasoning.

o3-mini finishes one point ahead overall, 56 to 55. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

o3-mini's sharpest advantage is in knowledge, where it averages 82.1 against 51.2. The single biggest benchmark swing on the page is SWE-bench Verified, 49.3 to 22.

o3-mini is also the more expensive model on tokens at $1.10 input / $4.40 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Gemini 3.1 Flash-Lite. That is roughly 11.0x on output cost alone. o3-mini is the reasoning model in the pair, while Gemini 3.1 Flash-Lite is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Gemini 3.1 Flash-Lite gives you the larger context window at 1M, compared with 200K for o3-mini.

Quick Verdict

Pick o3-mini if you want the stronger benchmark profile. Gemini 3.1 Flash-Lite only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.

Knowledge

o3-mini

o3-mini

82.1

Gemini 3.1 Flash-Lite

51.2

86.9
MMLU
63
77.2
GPQA
62
-
SuperGPQA
60
-
OpenBookQA
58
-
MMLU-Pro
63
-
HLE
1

Coding

o3-mini

o3-mini

49.3

Gemini 3.1 Flash-Lite

32.7

49.3
SWE-bench Verified
22
-
HumanEval
55
-
LiveCodeBench
21

Mathematics

o3-mini

o3-mini

87.3

Gemini 3.1 Flash-Lite

63.1

87.3
AIME 2024
65
-
AIME 2023
63
-
AIME 2025
64
-
HMMT Feb 2023
59
-
HMMT Feb 2024
61
-
HMMT Feb 2025
60
-
BRUMO 2025
62
-
MATH-500
71

Reasoning

Gemini 3.1 Flash-Lite
-
SimpleQA
60
-
MuSR
58
-
BBH
74

Instruction Following

o3-mini

o3-mini

93.9

Gemini 3.1 Flash-Lite

79

93.9
IFEval
79

Multilingual

Gemini 3.1 Flash-Lite
-
MGSM
73

Frequently Asked Questions

Which is better, o3-mini or Gemini 3.1 Flash-Lite?

o3-mini is ahead overall, 56 to 55. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 49.3 and 22.

Which is better for knowledge tasks, o3-mini or Gemini 3.1 Flash-Lite?

o3-mini has the edge for knowledge tasks in this comparison, averaging 82.1 versus 51.2. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, o3-mini or Gemini 3.1 Flash-Lite?

o3-mini has the edge for coding in this comparison, averaging 49.3 versus 32.7. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, o3-mini or Gemini 3.1 Flash-Lite?

o3-mini has the edge for math in this comparison, averaging 87.3 versus 63.1. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for instruction following, o3-mini or Gemini 3.1 Flash-Lite?

o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 79. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.