GPT-5.2 vs Seed 1.6 Flash

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

GPT-5.2 is clearly ahead on the aggregate, 88 to 56. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.2's sharpest advantage is in coding, where it averages 81.8 against 27.6. The single biggest benchmark swing on the page is SWE-bench Verified, 80 to 24.

GPT-5.2 is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.08 input / $0.30 output per 1M tokens for Seed 1.6 Flash. That is roughly 26.7x on output cost alone. GPT-5.2 gives you the larger context window at 400K, compared with 256K for Seed 1.6 Flash.

Quick Verdict

Pick GPT-5.2 if you want the stronger benchmark profile. Seed 1.6 Flash only becomes the better choice if you want the cheaper token bill.

Agentic

GPT-5.2

GPT-5.2

85.4

Seed 1.6 Flash

54.5

90
Terminal-Bench 2.0
52
84
BrowseComp
62
81
OSWorld-Verified
52

Coding

GPT-5.2

GPT-5.2

81.8

Seed 1.6 Flash

27.6

91
HumanEval
59
80
SWE-bench Verified
24
79
LiveCodeBench
25
85
SWE-bench Pro
31

Multimodal & Grounded

GPT-5.2

GPT-5.2

95

Seed 1.6 Flash

73.1

95
MMMU-Pro
74
95
OfficeQA Pro
72

Reasoning

GPT-5.2

GPT-5.2

93.2

Seed 1.6 Flash

66.8

95
SimpleQA
61
93
MuSR
59
96
BBH
75
91
LongBench v2
70
93
MRCRv2
74

Knowledge

GPT-5.2

GPT-5.2

79.5

Seed 1.6 Flash

47.3

99
MMLU
65
97
GPQA
64
95
SuperGPQA
62
93
OpenBookQA
60
88
MMLU-Pro
65
42
HLE
3
91
FrontierScience
57

Instruction Following

GPT-5.2

GPT-5.2

94

Seed 1.6 Flash

81

94
IFEval
81

Multilingual

GPT-5.2

GPT-5.2

92.4

Seed 1.6 Flash

72.8

95
MGSM
76
91
MMLU-ProX
71

Mathematics

GPT-5.2

GPT-5.2

97.2

Seed 1.6 Flash

67.1

99
AIME 2023
64
99
AIME 2024
66
98
AIME 2025
65
95
HMMT Feb 2023
60
97
HMMT Feb 2024
62
96
HMMT Feb 2025
61
96
BRUMO 2025
63
98
MATH-500
72

Frequently Asked Questions

Which is better, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 is ahead overall, 88 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 80 and 24.

Which is better for knowledge tasks, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for knowledge tasks in this comparison, averaging 79.5 versus 47.3. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for coding in this comparison, averaging 81.8 versus 27.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for math in this comparison, averaging 97.2 versus 67.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for reasoning in this comparison, averaging 93.2 versus 66.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for agentic tasks in this comparison, averaging 85.4 versus 54.5. 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 or Seed 1.6 Flash?

GPT-5.2 has the edge for multimodal and grounded tasks in this comparison, averaging 95 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 or Seed 1.6 Flash?

GPT-5.2 has the edge for instruction following in this comparison, averaging 94 versus 81. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.2 or Seed 1.6 Flash?

GPT-5.2 has the edge for multilingual tasks in this comparison, averaging 92.4 versus 72.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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