GPT-5.2 Pro vs Gemini 3.1 Flash-Lite

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

GPT-5.2 Pro is clearly ahead on the aggregate, 90 to 53. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.2 Pro's sharpest advantage is in coding, where it averages 84.8 against 24.7. The single biggest benchmark swing on the page is SWE-bench Verified, 83 to 22.

GPT-5.2 Pro is also the more expensive model on tokens at $25.00 input / $150.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Gemini 3.1 Flash-Lite. That is roughly 375.0x on output cost alone. GPT-5.2 Pro 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 400K for GPT-5.2 Pro.

Quick Verdict

Pick GPT-5.2 Pro 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.

Agentic

GPT-5.2 Pro

GPT-5.2 Pro

85.9

Gemini 3.1 Flash-Lite

49.2

88
Terminal-Bench 2.0
47
88
BrowseComp
60
82
OSWorld-Verified
44

Coding

GPT-5.2 Pro

GPT-5.2 Pro

84.8

Gemini 3.1 Flash-Lite

24.7

93
HumanEval
55
83
SWE-bench Verified
22
81
LiveCodeBench
21
89
SWE-bench Pro
29

Multimodal & Grounded

GPT-5.2 Pro

GPT-5.2 Pro

96

Gemini 3.1 Flash-Lite

73.1

96
MMMU-Pro
74
96
OfficeQA Pro
72

Reasoning

GPT-5.2 Pro

GPT-5.2 Pro

95.2

Gemini 3.1 Flash-Lite

65.8

97
SimpleQA
60
95
MuSR
58
98
BBH
74
93
LongBench v2
69
95
MRCRv2
73

Knowledge

GPT-5.2 Pro

GPT-5.2 Pro

81.5

Gemini 3.1 Flash-Lite

45.3

99
MMLU
63
99
GPQA
62
97
SuperGPQA
60
95
OpenBookQA
58
90
MMLU-Pro
63
44
HLE
1
93
FrontierScience
55

Instruction Following

GPT-5.2 Pro

GPT-5.2 Pro

95

Gemini 3.1 Flash-Lite

79

95
IFEval
79

Multilingual

GPT-5.2 Pro

GPT-5.2 Pro

93.4

Gemini 3.1 Flash-Lite

69.8

96
MGSM
73
92
MMLU-ProX
68

Mathematics

GPT-5.2 Pro

GPT-5.2 Pro

98.2

Gemini 3.1 Flash-Lite

66.1

99
AIME 2023
63
99
AIME 2024
65
99
AIME 2025
64
96
HMMT Feb 2023
59
98
HMMT Feb 2024
61
97
HMMT Feb 2025
60
97
BRUMO 2025
62
99
MATH-500
71

Frequently Asked Questions

Which is better, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro is ahead overall, 90 to 53. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 83 and 22.

Which is better for knowledge tasks, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for knowledge tasks in this comparison, averaging 81.5 versus 45.3. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for coding in this comparison, averaging 84.8 versus 24.7. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for math in this comparison, averaging 98.2 versus 66.1. Inside this category, HMMT Feb 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for reasoning in this comparison, averaging 95.2 versus 65.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for agentic tasks in this comparison, averaging 85.9 versus 49.2. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 96 versus 73.1. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for instruction following in this comparison, averaging 95 versus 79. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.2 Pro or Gemini 3.1 Flash-Lite?

GPT-5.2 Pro has the edge for multilingual tasks in this comparison, averaging 93.4 versus 69.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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