Claude Opus 4.6 vs Seed 1.6

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

Claude Opus 4.6 is clearly ahead on the aggregate, 85 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.6's sharpest advantage is in coding, where it averages 75.1 against 42.4. The single biggest benchmark swing on the page is LiveCodeBench, 75 to 38.

Claude Opus 4.6 is also the more expensive model on tokens at $15.00 input / $75.00 output per 1M tokens, versus $0.25 input / $2.00 output per 1M tokens for Seed 1.6. That is roughly 37.5x on output cost alone. Seed 1.6 is the reasoning model in the pair, while Claude Opus 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. Claude Opus 4.6 gives you the larger context window at 1M, compared with 256K for Seed 1.6.

Quick Verdict

Pick Claude Opus 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 want the stronger reasoning-first profile.

Agentic

Claude Opus 4.6

Claude Opus 4.6

79.2

Seed 1.6

62.3

80
Terminal-Bench 2.0
63
85
BrowseComp
67
74
OSWorld-Verified
58

Coding

Claude Opus 4.6

Claude Opus 4.6

75.1

Seed 1.6

42.4

91
HumanEval
64
80
SWE-bench Verified
46
75
LiveCodeBench
38
74
SWE-bench Pro
46

Multimodal & Grounded

Claude Opus 4.6

Claude Opus 4.6

94.6

Seed 1.6

79.6

95
MMMU-Pro
80
94
OfficeQA Pro
79

Reasoning

Claude Opus 4.6

Claude Opus 4.6

93.1

Seed 1.6

74.5

95
SimpleQA
69
93
MuSR
69
94
BBH
86
92
LongBench v2
77
92
MRCRv2
78

Knowledge

Claude Opus 4.6

Claude Opus 4.6

78.9

Seed 1.6

56.4

99
MMLU
73
97
GPQA
72
95
SuperGPQA
70
93
OpenBookQA
68
92
MMLU-Pro
75
38
HLE
11
88
FrontierScience
68

Instruction Following

Claude Opus 4.6

Claude Opus 4.6

95

Seed 1.6

87

95
IFEval
87

Multilingual

Claude Opus 4.6

Claude Opus 4.6

94.7

Seed 1.6

83.4

96
MGSM
88
94
MMLU-ProX
81

Mathematics

Claude Opus 4.6

Claude Opus 4.6

97.2

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
98
MATH-500
82

Frequently Asked Questions

Which is better, Claude Opus 4.6 or Seed 1.6?

Claude Opus 4.6 is ahead overall, 85 to 65. The biggest single separator in this matchup is LiveCodeBench, where the scores are 75 and 38.

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

Claude Opus 4.6 has the edge for knowledge tasks in this comparison, averaging 78.9 versus 56.4. Inside this category, HLE is the benchmark that creates the most daylight between them.

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

Claude Opus 4.6 has the edge for coding in this comparison, averaging 75.1 versus 42.4. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

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

Claude Opus 4.6 has the edge for math in this comparison, averaging 97.2 versus 75.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

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

Claude Opus 4.6 has the edge for reasoning in this comparison, averaging 93.1 versus 74.5. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

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

Claude Opus 4.6 has the edge for agentic tasks in this comparison, averaging 79.2 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 Opus 4.6 or Seed 1.6?

Claude Opus 4.6 has the edge for multimodal and grounded tasks in this comparison, averaging 94.6 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 Opus 4.6 or Seed 1.6?

Claude Opus 4.6 has the edge for instruction following in this comparison, averaging 95 versus 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.

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

Claude Opus 4.6 has the edge for multilingual tasks in this comparison, averaging 94.7 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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