Grok 4.1 Fast vs Seed 1.6 Flash

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 56. 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 27.6. The single biggest benchmark swing on the page is SWE-bench Verified, 68 to 24.

Seed 1.6 Flash 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 Flash.

Quick Verdict

Pick Grok 4.1 Fast if you want the stronger benchmark profile. Seed 1.6 Flash 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 Flash

54.5

74
Terminal-Bench 2.0
52
73
BrowseComp
62
66
OSWorld-Verified
52

Coding

Grok 4.1 Fast

Grok 4.1 Fast

59.5

Seed 1.6 Flash

27.6

86
HumanEval
59
68
SWE-bench Verified
24
54
LiveCodeBench
25
63
SWE-bench Pro
31

Multimodal & Grounded

Grok 4.1 Fast

Grok 4.1 Fast

87.4

Seed 1.6 Flash

73.1

91
MMMU-Pro
74
83
OfficeQA Pro
72

Reasoning

Grok 4.1 Fast

Grok 4.1 Fast

88.3

Seed 1.6 Flash

66.8

90
SimpleQA
61
88
MuSR
59
87
BBH
75
87
LongBench v2
70
89
MRCRv2
74

Knowledge

Grok 4.1 Fast

Grok 4.1 Fast

69.2

Seed 1.6 Flash

47.3

94
MMLU
65
92
GPQA
64
90
SuperGPQA
62
88
OpenBookQA
60
81
MMLU-Pro
65
20
HLE
3
83
FrontierScience
57

Instruction Following

Grok 4.1 Fast

Grok 4.1 Fast

90

Seed 1.6 Flash

81

90
IFEval
81

Multilingual

Grok 4.1 Fast

Grok 4.1 Fast

84.8

Seed 1.6 Flash

72.8

88
MGSM
76
83
MMLU-ProX
71

Mathematics

Grok 4.1 Fast

Grok 4.1 Fast

92.3

Seed 1.6 Flash

67.1

96
AIME 2023
64
98
AIME 2024
66
97
AIME 2025
65
92
HMMT Feb 2023
60
94
HMMT Feb 2024
62
93
HMMT Feb 2025
61
95
BRUMO 2025
63
89
MATH-500
72

Frequently Asked Questions

Which is better, Grok 4.1 Fast or Seed 1.6 Flash?

Grok 4.1 Fast is ahead overall, 76 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 68 and 24.

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

Grok 4.1 Fast has the edge for knowledge tasks in this comparison, averaging 69.2 versus 47.3. 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 Flash?

Grok 4.1 Fast has the edge for coding in this comparison, averaging 59.5 versus 27.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

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

Grok 4.1 Fast has the edge for math in this comparison, averaging 92.3 versus 67.1. 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 Flash?

Grok 4.1 Fast has the edge for reasoning in this comparison, averaging 88.3 versus 66.8. 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 Flash?

Grok 4.1 Fast has the edge for agentic tasks in this comparison, averaging 71 versus 54.5. 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 Flash?

Grok 4.1 Fast has the edge for multimodal and grounded tasks in this comparison, averaging 87.4 versus 73.1. 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 Flash?

Grok 4.1 Fast has the edge for instruction following in this comparison, averaging 90 versus 81. 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 Flash?

Grok 4.1 Fast has the edge for multilingual tasks in this comparison, averaging 84.8 versus 72.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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