GPT-5.1-Codex-Max vs Seed-2.0-Mini

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

GPT-5.1-Codex-Max is clearly ahead on the aggregate, 84 to 53. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.1-Codex-Max'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 Pro, 84 to 29.

GPT-5.1-Codex-Max is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Seed-2.0-Mini. That is roughly 20.0x on output cost alone. GPT-5.1-Codex-Max is the reasoning model in the pair, while Seed-2.0-Mini 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. GPT-5.1-Codex-Max gives you the larger context window at 400K, compared with 256K for Seed-2.0-Mini.

Quick Verdict

Pick GPT-5.1-Codex-Max if you want the stronger benchmark profile. Seed-2.0-Mini only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

86

Seed-2.0-Mini

46.2

90
Terminal-Bench 2.0
43
85
BrowseComp
53
82
OSWorld-Verified
45

Coding

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

75.5

Seed-2.0-Mini

24.7

94
HumanEval
55
75
SWE-bench Verified
22
67
LiveCodeBench
21
84
SWE-bench Pro
29

Multimodal & Grounded

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

88.2

Seed-2.0-Mini

73.1

85
MMMU-Pro
74
92
OfficeQA Pro
72

Reasoning

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

92.1

Seed-2.0-Mini

64.8

94
SimpleQA
59
92
MuSR
57
92
BBH
73
90
LongBench v2
68
93
MRCRv2
72

Knowledge

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

72.6

Seed-2.0-Mini

44.6

98
MMLU
62
96
GPQA
61
94
SuperGPQA
59
92
OpenBookQA
57
82
MMLU-Pro
62
27
HLE
1
84
FrontierScience
54

Instruction Following

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

91

Seed-2.0-Mini

80

91
IFEval
80

Multilingual

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

87.7

Seed-2.0-Mini

71.8

89
MGSM
75
87
MMLU-ProX
70

Mathematics

GPT-5.1-Codex-Max

GPT-5.1-Codex-Max

94.9

Seed-2.0-Mini

65.1

99
AIME 2023
62
99
AIME 2024
64
98
AIME 2025
63
95
HMMT Feb 2023
58
97
HMMT Feb 2024
60
96
HMMT Feb 2025
59
96
BRUMO 2025
61
93
MATH-500
70

Frequently Asked Questions

Which is better, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max is ahead overall, 84 to 53. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 84 and 29.

Which is better for knowledge tasks, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for knowledge tasks in this comparison, averaging 72.6 versus 44.6. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for coding in this comparison, averaging 75.5 versus 24.7. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for math in this comparison, averaging 94.9 versus 65.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for reasoning in this comparison, averaging 92.1 versus 64.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for agentic tasks in this comparison, averaging 86 versus 46.2. 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-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for multimodal and grounded tasks in this comparison, averaging 88.2 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-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for instruction following in this comparison, averaging 91 versus 80. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.1-Codex-Max or Seed-2.0-Mini?

GPT-5.1-Codex-Max has the edge for multilingual tasks in this comparison, averaging 87.7 versus 71.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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