Claude Sonnet 4.6 vs Seed 1.6

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

Claude Sonnet 4.6 is clearly ahead on the aggregate, 78 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Sonnet 4.6's sharpest advantage is in mathematics, where it averages 94.1 against 75.9. The single biggest benchmark swing on the page is HumanEval, 93 to 64.

Claude Sonnet 4.6 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.25 input / $2.00 output per 1M tokens for Seed 1.6. That is roughly 7.5x on output cost alone. Seed 1.6 is the reasoning model in the pair, while Claude Sonnet 4.6 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 200K for Claude Sonnet 4.6.

Quick Verdict

Pick Claude Sonnet 4.6 if you want the stronger benchmark profile. Seed 1.6 only becomes the better choice if you want the cheaper token bill or you need the larger 256K context window.

Agentic

Claude Sonnet 4.6

Claude Sonnet 4.6

71.1

Seed 1.6

62.3

70
Terminal-Bench 2.0
63
77
BrowseComp
67
68
OSWorld-Verified
58

Coding

Claude Sonnet 4.6

Claude Sonnet 4.6

60

Seed 1.6

42.4

93
HumanEval
64
69
SWE-bench Verified
46
54
LiveCodeBench
38
64
SWE-bench Pro
46

Multimodal & Grounded

Claude Sonnet 4.6

Claude Sonnet 4.6

91.9

Seed 1.6

79.6

95
MMMU-Pro
80
88
OfficeQA Pro
79

Reasoning

Claude Sonnet 4.6

Claude Sonnet 4.6

87.6

Seed 1.6

74.5

95
SimpleQA
69
93
MuSR
69
88
BBH
86
83
LongBench v2
77
79
MRCRv2
78

Knowledge

Claude Sonnet 4.6

Claude Sonnet 4.6

71.8

Seed 1.6

56.4

99
MMLU
73
97
GPQA
72
95
SuperGPQA
70
93
OpenBookQA
68
83
MMLU-Pro
75
21
HLE
11
85
FrontierScience
68

Instruction Following

Claude Sonnet 4.6

Claude Sonnet 4.6

91

Seed 1.6

87

91
IFEval
87

Multilingual

Claude Sonnet 4.6

Claude Sonnet 4.6

89.7

Seed 1.6

83.4

91
MGSM
88
89
MMLU-ProX
81

Mathematics

Claude Sonnet 4.6

Claude Sonnet 4.6

94.1

Seed 1.6

75.9

99
AIME 2023
72
99
AIME 2024
74
98
AIME 2025
73
95
HMMT Feb 2023
68
97
HMMT Feb 2024
70
96
HMMT Feb 2025
69
96
BRUMO 2025
71
91
MATH-500
82

Frequently Asked Questions

Which is better, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 is ahead overall, 78 to 65. The biggest single separator in this matchup is HumanEval, where the scores are 93 and 64.

Which is better for knowledge tasks, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for knowledge tasks in this comparison, averaging 71.8 versus 56.4. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for coding in this comparison, averaging 60 versus 42.4. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for math in this comparison, averaging 94.1 versus 75.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for reasoning in this comparison, averaging 87.6 versus 74.5. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for agentic tasks in this comparison, averaging 71.1 versus 62.3. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for multimodal and grounded tasks in this comparison, averaging 91.9 versus 79.6. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for instruction following in this comparison, averaging 91 versus 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Claude Sonnet 4.6 or Seed 1.6?

Claude Sonnet 4.6 has the edge for multilingual tasks in this comparison, averaging 89.7 versus 83.4. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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