Step 3.5 Flash vs Grok 3 [Beta]

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

Step 3.5 Flash is clearly ahead on the aggregate, 66 to 38. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Step 3.5 Flash's sharpest advantage is in mathematics, where it averages 84.5 against 49.1. The single biggest benchmark swing on the page is MuSR, 82 to 38.

Step 3.5 Flash gives you the larger context window at 256K, compared with 128K for Grok 3 [Beta].

Quick Verdict

Pick Step 3.5 Flash if you want the stronger benchmark profile. Grok 3 [Beta] only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.

Agentic

Step 3.5 Flash

Step 3.5 Flash

60.2

Grok 3 [Beta]

35.7

62
Terminal-Bench 2.0
32
66
BrowseComp
41
54
OSWorld-Verified
36

Coding

Step 3.5 Flash

Step 3.5 Flash

47.1

Grok 3 [Beta]

16.3

77
HumanEval
34
48
SWE-bench Verified
19
45
LiveCodeBench
11
49
SWE-bench Pro
21

Multimodal & Grounded

Step 3.5 Flash

Step 3.5 Flash

66.7

Grok 3 [Beta]

43.2

64
MMMU-Pro
40
70
OfficeQA Pro
47

Reasoning

Step 3.5 Flash

Step 3.5 Flash

78.3

Grok 3 [Beta]

47.4

82
SimpleQA
40
82
MuSR
38
83
BBH
62
74
LongBench v2
53
73
MRCRv2
52

Knowledge

Step 3.5 Flash

Step 3.5 Flash

60.8

Grok 3 [Beta]

34

84
MMLU
42
83
GPQA
41
81
SuperGPQA
39
79
OpenBookQA
37
76
MMLU-Pro
53
12
HLE
3
71
FrontierScience
40

Instruction Following

Step 3.5 Flash

Step 3.5 Flash

87

Grok 3 [Beta]

67

87
IFEval
67

Multilingual

Step 3.5 Flash

Step 3.5 Flash

82.8

Grok 3 [Beta]

58.7

86
MGSM
60
81
MMLU-ProX
58

Mathematics

Step 3.5 Flash

Step 3.5 Flash

84.5

Grok 3 [Beta]

49.1

85
AIME 2023
42
87
AIME 2024
44
86
AIME 2025
43
81
HMMT Feb 2023
38
83
HMMT Feb 2024
40
82
HMMT Feb 2025
39
84
BRUMO 2025
41
85
MATH-500
59

Frequently Asked Questions

Which is better, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash is ahead overall, 66 to 38. The biggest single separator in this matchup is MuSR, where the scores are 82 and 38.

Which is better for knowledge tasks, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for knowledge tasks in this comparison, averaging 60.8 versus 34. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for coding in this comparison, averaging 47.1 versus 16.3. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for math in this comparison, averaging 84.5 versus 49.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for reasoning in this comparison, averaging 78.3 versus 47.4. Inside this category, MuSR is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for agentic tasks in this comparison, averaging 60.2 versus 35.7. 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, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 66.7 versus 43.2. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for instruction following in this comparison, averaging 87 versus 67. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Step 3.5 Flash or Grok 3 [Beta]?

Step 3.5 Flash has the edge for multilingual tasks in this comparison, averaging 82.8 versus 58.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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