Seed 1.6 vs Qwen3.5 397B

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

Seed 1.6 has the cleaner overall profile here, landing at 65 versus 62. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Seed 1.6's sharpest advantage is in multimodal & grounded, where it averages 79.6 against 61.4. The single biggest benchmark swing on the page is MMMU-Pro, 80 to 56. Qwen3.5 397B does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

Seed 1.6 is also the more expensive model on tokens at $0.25 input / $2.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Qwen3.5 397B. That is roughly Infinityx on output cost alone. Seed 1.6 is the reasoning model in the pair, while Qwen3.5 397B 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. Seed 1.6 gives you the larger context window at 256K, compared with 128K for Qwen3.5 397B.

Quick Verdict

Pick Seed 1.6 if you want the stronger benchmark profile. Qwen3.5 397B only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Agentic

Seed 1.6

Seed 1.6

62.3

Qwen3.5 397B

56.9

63
Terminal-Bench 2.0
58
67
BrowseComp
62
58
OSWorld-Verified
52

Coding

Seed 1.6

Seed 1.6

42.4

Qwen3.5 397B

40.7

64
HumanEval
75
46
SWE-bench Verified
42
38
LiveCodeBench
39
46
SWE-bench Pro
42

Multimodal & Grounded

Seed 1.6

Seed 1.6

79.6

Qwen3.5 397B

61.4

80
MMMU-Pro
56
79
OfficeQA Pro
68

Reasoning

Qwen3.5 397B

Seed 1.6

74.5

Qwen3.5 397B

75.9

69
SimpleQA
80
69
MuSR
78
86
BBH
82
77
LongBench v2
72
78
MRCRv2
71

Knowledge

Qwen3.5 397B

Seed 1.6

56.4

Qwen3.5 397B

59.3

73
MMLU
83
72
GPQA
82
70
SuperGPQA
80
68
OpenBookQA
78
75
MMLU-Pro
73
11
HLE
10
68
FrontierScience
71

Instruction Following

Seed 1.6

Seed 1.6

87

Qwen3.5 397B

82

87
IFEval
82

Multilingual

Seed 1.6

Seed 1.6

83.4

Qwen3.5 397B

78.8

88
MGSM
82
81
MMLU-ProX
77

Mathematics

Qwen3.5 397B

Seed 1.6

75.9

Qwen3.5 397B

81.6

72
AIME 2023
83
74
AIME 2024
85
73
AIME 2025
84
68
HMMT Feb 2023
79
70
HMMT Feb 2024
81
69
HMMT Feb 2025
80
71
BRUMO 2025
82
82
MATH-500
81

Frequently Asked Questions

Which is better, Seed 1.6 or Qwen3.5 397B?

Seed 1.6 is ahead overall, 65 to 62. The biggest single separator in this matchup is MMMU-Pro, where the scores are 80 and 56.

Which is better for knowledge tasks, Seed 1.6 or Qwen3.5 397B?

Qwen3.5 397B has the edge for knowledge tasks in this comparison, averaging 59.3 versus 56.4. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Seed 1.6 or Qwen3.5 397B?

Seed 1.6 has the edge for coding in this comparison, averaging 42.4 versus 40.7. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Seed 1.6 or Qwen3.5 397B?

Qwen3.5 397B has the edge for math in this comparison, averaging 81.6 versus 75.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Seed 1.6 or Qwen3.5 397B?

Qwen3.5 397B has the edge for reasoning in this comparison, averaging 75.9 versus 74.5. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Seed 1.6 or Qwen3.5 397B?

Seed 1.6 has the edge for agentic tasks in this comparison, averaging 62.3 versus 56.9. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Seed 1.6 or Qwen3.5 397B?

Seed 1.6 has the edge for multimodal and grounded tasks in this comparison, averaging 79.6 versus 61.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Seed 1.6 or Qwen3.5 397B?

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, Seed 1.6 or Qwen3.5 397B?

Seed 1.6 has the edge for multilingual tasks in this comparison, averaging 83.4 versus 78.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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