GPT-5 mini vs Seed 1.6

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

GPT-5 mini is clearly ahead on the aggregate, 69 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5 mini's sharpest advantage is in mathematics, where it averages 87.2 against 75.9. The single biggest benchmark swing on the page is AIME 2023, 90 to 72. Seed 1.6 does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.

Seed 1.6 gives you the larger context window at 256K, compared with 128K for GPT-5 mini.

Quick Verdict

Pick GPT-5 mini if you want the stronger benchmark profile. Seed 1.6 only becomes the better choice if instruction following is the priority or you need the larger 256K context window.

Agentic

GPT-5 mini

GPT-5 mini

65.7

Seed 1.6

62.3

68
Terminal-Bench 2.0
63
70
BrowseComp
67
60
OSWorld-Verified
58

Coding

GPT-5 mini

GPT-5 mini

42.8

Seed 1.6

42.4

80
HumanEval
64
41
SWE-bench Verified
46
37
LiveCodeBench
38
49
SWE-bench Pro
46

Multimodal & Grounded

GPT-5 mini

GPT-5 mini

83.8

Seed 1.6

79.6

86
MMMU-Pro
80
81
OfficeQA Pro
79

Reasoning

GPT-5 mini

GPT-5 mini

81.8

Seed 1.6

74.5

84
SimpleQA
69
82
MuSR
69
87
BBH
86
80
LongBench v2
77
79
MRCRv2
78

Knowledge

GPT-5 mini

GPT-5 mini

62.8

Seed 1.6

56.4

88
MMLU
73
86
GPQA
72
84
SuperGPQA
70
82
OpenBookQA
68
73
MMLU-Pro
75
16
HLE
11
75
FrontierScience
68

Instruction Following

Seed 1.6

GPT-5 mini

82

Seed 1.6

87

82
IFEval
87

Multilingual

Seed 1.6

GPT-5 mini

80.1

Seed 1.6

83.4

82
MGSM
88
79
MMLU-ProX
81

Mathematics

GPT-5 mini

GPT-5 mini

87.2

Seed 1.6

75.9

90
AIME 2023
72
92
AIME 2024
74
91
AIME 2025
73
86
HMMT Feb 2023
68
88
HMMT Feb 2024
70
87
HMMT Feb 2025
69
89
BRUMO 2025
71
85
MATH-500
82

Frequently Asked Questions

Which is better, GPT-5 mini or Seed 1.6?

GPT-5 mini is ahead overall, 69 to 65. The biggest single separator in this matchup is AIME 2023, where the scores are 90 and 72.

Which is better for knowledge tasks, GPT-5 mini or Seed 1.6?

GPT-5 mini has the edge for knowledge tasks in this comparison, averaging 62.8 versus 56.4. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5 mini or Seed 1.6?

GPT-5 mini has the edge for coding in this comparison, averaging 42.8 versus 42.4. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5 mini or Seed 1.6?

GPT-5 mini has the edge for math in this comparison, averaging 87.2 versus 75.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5 mini or Seed 1.6?

GPT-5 mini has the edge for reasoning in this comparison, averaging 81.8 versus 74.5. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5 mini or Seed 1.6?

GPT-5 mini has the edge for agentic tasks in this comparison, averaging 65.7 versus 62.3. 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 mini or Seed 1.6?

GPT-5 mini has the edge for multimodal and grounded tasks in this comparison, averaging 83.8 versus 79.6. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5 mini or Seed 1.6?

Seed 1.6 has the edge for instruction following in this comparison, averaging 87 versus 82. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5 mini or Seed 1.6?

Seed 1.6 has the edge for multilingual tasks in this comparison, averaging 83.4 versus 80.1. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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