Grok 4.1 Fast vs Seed 1.6

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

Grok 4.1 Fast is clearly ahead on the aggregate, 76 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Grok 4.1 Fast's sharpest advantage is in coding, where it averages 59.5 against 42.4. The single biggest benchmark swing on the page is AIME 2023, 96 to 72.

Seed 1.6 is the reasoning model in the pair, while Grok 4.1 Fast 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. Grok 4.1 Fast gives you the larger context window at 1M, compared with 256K for Seed 1.6.

Quick Verdict

Pick Grok 4.1 Fast if you want the stronger benchmark profile. Seed 1.6 only becomes the better choice if you want the stronger reasoning-first profile.

Agentic

Grok 4.1 Fast

Grok 4.1 Fast

71

Seed 1.6

62.3

74
Terminal-Bench 2.0
63
73
BrowseComp
67
66
OSWorld-Verified
58

Coding

Grok 4.1 Fast

Grok 4.1 Fast

59.5

Seed 1.6

42.4

86
HumanEval
64
68
SWE-bench Verified
46
54
LiveCodeBench
38
63
SWE-bench Pro
46

Multimodal & Grounded

Grok 4.1 Fast

Grok 4.1 Fast

87.4

Seed 1.6

79.6

91
MMMU-Pro
80
83
OfficeQA Pro
79

Reasoning

Grok 4.1 Fast

Grok 4.1 Fast

88.3

Seed 1.6

74.5

90
SimpleQA
69
88
MuSR
69
87
BBH
86
87
LongBench v2
77
89
MRCRv2
78

Knowledge

Grok 4.1 Fast

Grok 4.1 Fast

69.2

Seed 1.6

56.4

94
MMLU
73
92
GPQA
72
90
SuperGPQA
70
88
OpenBookQA
68
81
MMLU-Pro
75
20
HLE
11
83
FrontierScience
68

Instruction Following

Grok 4.1 Fast

Grok 4.1 Fast

90

Seed 1.6

87

90
IFEval
87

Multilingual

Grok 4.1 Fast

Grok 4.1 Fast

84.8

Seed 1.6

83.4

88
MGSM
88
83
MMLU-ProX
81

Mathematics

Grok 4.1 Fast

Grok 4.1 Fast

92.3

Seed 1.6

75.9

96
AIME 2023
72
98
AIME 2024
74
97
AIME 2025
73
92
HMMT Feb 2023
68
94
HMMT Feb 2024
70
93
HMMT Feb 2025
69
95
BRUMO 2025
71
89
MATH-500
82

Frequently Asked Questions

Which is better, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast is ahead overall, 76 to 65. The biggest single separator in this matchup is AIME 2023, where the scores are 96 and 72.

Which is better for knowledge tasks, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for knowledge tasks in this comparison, averaging 69.2 versus 56.4. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for coding in this comparison, averaging 59.5 versus 42.4. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for math in this comparison, averaging 92.3 versus 75.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for reasoning in this comparison, averaging 88.3 versus 74.5. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for agentic tasks in this comparison, averaging 71 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, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for multimodal and grounded tasks in this comparison, averaging 87.4 versus 79.6. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for instruction following in this comparison, averaging 90 versus 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Grok 4.1 Fast or Seed 1.6?

Grok 4.1 Fast has the edge for multilingual tasks in this comparison, averaging 84.8 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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