Model comparison

Grok 4.1 Fast vs Grok 4.6

Grok 4.6 is the stronger model overall, scoring 56.8 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 11× less per token, which makes it the better buy when Grok 4.6's lead doesn't matter for your workload.

Last verified . 25 shared benchmarks.

Grok 4.1 Fast xAI

40.9

Rank #131 Confirmed

Grok 4.6 xAI

56.8

Rank #19 Confirmed

Summary

  • They share 25 benchmarks with published results for both. Grok 4.1 Fast scores higher in 0 categories and Grok 4.6 in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Grok 4.6 leads 66.8 to 30.9.
  • The biggest single-benchmark swing is ProofBench: 4% for Grok 4.1 Fast and 51% for Grok 4.6.
  • Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $2 / $6 for Grok 4.6.
  • Grok 4.6 accepts more context: 500K tokens versus 128K.

Side by side

Grok 4.1 Fast and Grok 4.6 specifications
Grok 4.1 FastGrok 4.6
ProviderxAIxAI
Noometry Index40.956.8
Released2025-06-272026-08-12
WeightsProprietaryProprietary
Context window128K500K
Max output30K500K
Input $ / M tokens$0.20$2
Output $ / M tokens$0.50$6
Results tracked3249

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Category by category

Coding Grok 4.6 leads

Grok 4.1 Fast: 33.8 (#236), Grok 4.6: 58.0 (#14)

Coding benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena WebDev12411620
LMArena Coding14111464
ALE-Bench394.931,508
DeepSWE—67.5%
FrontierCode—48%
CursorBench—41.4%
FrontierSWE—25.3%
SciCode—56.5%
WeirdML—67.3%

Agentic & Tool Use Grok 4.6 leads

Grok 4.1 Fast: 36.1 (#35), Grok 4.6: 39.4 (#25)

Agentic & Tool Use benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
Vending-Bench 21,1079,047
APEX-Agents—65.3%
Berkeley Function Calling Leaderboard69.6%—
τ²-bench Banking13.1%—
GDP.pdf—17.2%
LMArena Search1171—

Reasoning Grok 4.6 leads

Grok 4.1 Fast: 42.3 (#45), Grok 4.6: 61.3 (#18)

Reasoning benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
SimpleBench56%75.9%
NYT Connections (extended)87.4%80%
LMArena Hard Prompts14071445
DTBench87.7%97.3%
ARC-AGI-2—67.1%
ARC-AGI-1—87.5%
CritPt—19.7%
Chess Puzzles—40%
EBR-Bench—30.5%
Mystery Game Puzzles—34%
LMCA—48.5%
Epoch Capabilities Index—156.48
ForecastBench61—

Math Grok 4.6 leads

Grok 4.1 Fast: 30.9 (#201), Grok 4.6: 66.8 (#19)

Math benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
ProofBench4%51%
LMArena Math14081416
FrontierMath (Tiers 1-3)—66%
FrontierMath Tier 4—31.7%
MathArena Final-Answer Competitions60.9%—
OTIS Mock AIME 2024-2025—99.2%

Knowledge Grok 4.6 leads

Grok 4.1 Fast: 32.6 (#203), Grok 4.6: 63.3 (#18)

Knowledge benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Expert13981463
GPQA Diamond—94%
SimpleQA Verified—49.3%
Vectara Hallucination Rate17.8%—

Multimodal Grok 4.6 leads

Grok 4.1 Fast: 36.3 (#71), Grok 4.6: 43.9 (#18)

Multimodal benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Vision12011265
Blueprint-Bench 2—33.2%
Furniture Assembly—40%
LMArena Document—1452

Multilingual Grok 4.6 leads

Grok 4.1 Fast: 51.1 (#110), Grok 4.6: 53.3 (#67)

Multilingual benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Non-English13911422
LMArena Chinese14411479
LMArena French14161458
LMArena German14041425
LMArena Japanese13471383
LMArena Korean13611395
LMArena Russian13871427
LMArena Spanish14111408

Instruction Following Grok 4.6 leads

Grok 4.1 Fast: 72.8 (#127), Grok 4.6: 75.6 (#59)

Instruction Following benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Instruction Following13761431

Long Context Grok 4.6 leads

Grok 4.1 Fast: 42.4 (#121), Grok 4.6: 44.4 (#62)

Long Context benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Longer Query13901453

Writing & Preference Grok 4.6 leads

Grok 4.1 Fast: 57.4 (#126), Grok 4.6: 62.5 (#77)

Writing & Preference benchmarks
BenchmarkGrok 4.1 FastGrok 4.6
LMArena Text14081427
LMArena Creative Writing13941430
LMArena Multi-Turn13891422
EQ-Bench Creative Writing1327—

Frequently asked questions

Is Grok 4.1 Fast better than Grok 4.6?

Grok 4.6 is the stronger model overall, scoring 56.8 to 40.9 on the Noometry Index. Grok 4.1 Fast costs 11× less per token, which makes it the better buy when Grok 4.6's lead doesn't matter for your workload.

Which is cheaper, Grok 4.1 Fast or Grok 4.6?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Grok 4.6 lists at $2 and $6.

Is Grok 4.1 Fast or Grok 4.6 better for coding?

Grok 4.6 scores higher on coding benchmarks: 58.0 versus 33.8 in the Noometry coding category.

Which has the bigger context window?

Grok 4.6 does, with 500K tokens against 128K.

How many benchmarks do Grok 4.1 Fast and Grok 4.6 share?

25 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Grok 4.6 has 49.

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