GPT-5.2 Instant vs Gemini 3.1 Flash-Lite

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

GPT-5.2 Instant is clearly ahead on the aggregate, 85 to 53. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.2 Instant's sharpest advantage is in coding, where it averages 75.5 against 24.7. The single biggest benchmark swing on the page is SWE-bench Verified, 75 to 22.

GPT-5.2 Instant is also the more expensive model on tokens at $1.50 input / $6.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Gemini 3.1 Flash-Lite. That is roughly 15.0x on output cost alone. GPT-5.2 Instant 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 128K for GPT-5.2 Instant.

Quick Verdict

Pick GPT-5.2 Instant 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 Instant

GPT-5.2 Instant

79.6

Gemini 3.1 Flash-Lite

49.2

83
Terminal-Bench 2.0
47
82
BrowseComp
60
74
OSWorld-Verified
44

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

Gemini 3.1 Flash-Lite

24.7

87
HumanEval
55
75
SWE-bench Verified
22
74
LiveCodeBench
21
77
SWE-bench Pro
29

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

Gemini 3.1 Flash-Lite

73.1

94
MMMU-Pro
74
92
OfficeQA Pro
72

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

Gemini 3.1 Flash-Lite

65.8

95
SimpleQA
60
93
MuSR
58
96
BBH
74
89
LongBench v2
69
84
MRCRv2
73

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

Gemini 3.1 Flash-Lite

45.3

98
MMLU
63
97
GPQA
62
95
SuperGPQA
60
93
OpenBookQA
58
88
MMLU-Pro
63
43
HLE
1
91
FrontierScience
55

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

Gemini 3.1 Flash-Lite

79

95
IFEval
79

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

Gemini 3.1 Flash-Lite

69.8

95
MGSM
73
94
MMLU-ProX
68

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

Gemini 3.1 Flash-Lite

66.1

99
AIME 2023
63
99
AIME 2024
65
98
AIME 2025
64
95
HMMT Feb 2023
59
97
HMMT Feb 2024
61
96
HMMT Feb 2025
60
96
BRUMO 2025
62
98
MATH-500
71

Frequently Asked Questions

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

GPT-5.2 Instant is ahead overall, 85 to 53. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 75 and 22.

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

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 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 Instant or Gemini 3.1 Flash-Lite?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 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 Instant or Gemini 3.1 Flash-Lite?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 66.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

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

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 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 Instant or Gemini 3.1 Flash-Lite?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 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 Instant or Gemini 3.1 Flash-Lite?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 73.1. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

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

GPT-5.2 Instant 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 Instant or Gemini 3.1 Flash-Lite?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 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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