GPT-5.2 Instant vs Gemini 2.5 Flash

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 49. 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 21.7. The single biggest benchmark swing on the page is LiveCodeBench, 74 to 18.

GPT-5.2 Instant is also the more expensive model on tokens at $1.50 input / $6.00 output per 1M tokens, versus $0.15 input / $0.60 output per 1M tokens for Gemini 2.5 Flash. That is roughly 10.0x on output cost alone. GPT-5.2 Instant is the reasoning model in the pair, while Gemini 2.5 Flash 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 2.5 Flash 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 2.5 Flash 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 2.5 Flash

46.5

83
Terminal-Bench 2.0
44
82
BrowseComp
58
74
OSWorld-Verified
41

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

Gemini 2.5 Flash

21.7

87
HumanEval
42
75
SWE-bench Verified
23
74
LiveCodeBench
18
77
SWE-bench Pro
25

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

Gemini 2.5 Flash

67.7

94
MMMU-Pro
69
92
OfficeQA Pro
66

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

Gemini 2.5 Flash

59.2

95
SimpleQA
48
93
MuSR
46
96
BBH
75
89
LongBench v2
68
84
MRCRv2
68

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

Gemini 2.5 Flash

40.5

98
MMLU
50
97
GPQA
49
95
SuperGPQA
47
93
OpenBookQA
45
88
MMLU-Pro
64
43
HLE
1
91
FrontierScience
49

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

Gemini 2.5 Flash

79

95
IFEval
79

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

Gemini 2.5 Flash

70.8

95
MGSM
74
94
MMLU-ProX
69

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

Gemini 2.5 Flash

59.4

99
AIME 2023
50
99
AIME 2024
52
98
AIME 2025
51
95
HMMT Feb 2023
46
97
HMMT Feb 2024
48
96
HMMT Feb 2025
47
96
BRUMO 2025
49
98
MATH-500
72

Frequently Asked Questions

Which is better, GPT-5.2 Instant or Gemini 2.5 Flash?

GPT-5.2 Instant is ahead overall, 85 to 49. The biggest single separator in this matchup is LiveCodeBench, where the scores are 74 and 18.

Which is better for knowledge tasks, GPT-5.2 Instant or Gemini 2.5 Flash?

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 40.5. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Instant or Gemini 2.5 Flash?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 versus 21.7. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Instant or Gemini 2.5 Flash?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 59.4. 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 2.5 Flash?

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 versus 59.2. 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 2.5 Flash?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 versus 46.5. 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 2.5 Flash?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 67.7. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.2 Instant or Gemini 2.5 Flash?

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 2.5 Flash?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 versus 70.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 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.