Noometry

Model comparison

Grok 4.1 Fast vs Grok Build 0.1

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 36.4 on the Noometry Index.

Last verified . 0 shared benchmarks.

Grok 4.1 Fast xAI

41.4

Rank #136 Confirmed

Grok Build 0.1 xAI

36.4

Rank #216 Reported

Summary

  • The widest gap is in agentic & tool use, where Grok 4.1 Fast leads 36.3 to 22.7.
  • Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $1 / $2 for Grok Build 0.1.
  • Grok Build 0.1 accepts more context: 256K tokens versus 128K.

Side by side

Grok 4.1 FastGrok Build 0.1
ProviderxAIxAI
Noometry Index41.436.4
Released2025-06-272026-04-16
WeightsProprietaryProprietary
Context window128K256K
Max output30K256K
Input $ / M tokens$0.20$1
Output $ / M tokens$0.50$2
Results tracked323

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Category by category

Coding Grok Build 0.1 leads

Grok 4.1 Fast: 34.1 (#245), Grok Build 0.1: 43.1 (#91)

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena WebDev1242—
SciCode—50.2%
LMArena Coding1411—
ALE-Bench394.93—

Agentic & Tool Use Grok 4.1 Fast leads

Grok 4.1 Fast: 36.3 (#39), Grok Build 0.1: 22.7 (#129)

BenchmarkGrok 4.1 FastGrok Build 0.1
Berkeley Function Calling Leaderboard69.6%—
τ²-bench Banking13.1%—
GBAEval—2.4%
LMArena Search1171—
Vending-Bench 21,107—

Reasoning Grok 4.1 Fast leads

Grok 4.1 Fast: 43.4 (#49), Grok Build 0.1: 32.2 (#77)

BenchmarkGrok 4.1 FastGrok Build 0.1
SimpleBench56%—
NYT Connections (extended)87.4%—
CritPt—9.1%
LMArena Hard Prompts1407—
DTBench87.7%—
ForecastBench61—

Math Not comparable

Grok 4.1 Fast: 31.9 (#221), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
MathArena Final-Answer Competitions60.9%—
ProofBench4%—
LMArena Math1408—

Knowledge Not comparable

Grok 4.1 Fast: 33.1 (#207), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
Vectara Hallucination Rate17.8%—
LMArena Expert1399—

Multimodal Not comparable

Grok 4.1 Fast: 37.0 (#76), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena Vision1201—

Multilingual Not comparable

Grok 4.1 Fast: 51.0 (#114), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena Non-English1391—
LMArena Chinese1441—
LMArena French1415—
LMArena German1404—
LMArena Japanese1349—
LMArena Korean1361—
LMArena Russian1387—
LMArena Spanish1413—

Instruction Following Not comparable

Grok 4.1 Fast: 72.7 (#133), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena Instruction Following1376—

Long Context Not comparable

Grok 4.1 Fast: 42.4 (#126), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena Longer Query1390—

Writing & Preference Not comparable

Grok 4.1 Fast: 57.2 (#131), Grok Build 0.1: —

BenchmarkGrok 4.1 FastGrok Build 0.1
LMArena Text1408—
LMArena Creative Writing1394—
EQ-Bench Creative Writing1327—
LMArena Multi-Turn1389—

Frequently asked questions

Is Grok 4.1 Fast better than Grok Build 0.1?

Grok 4.1 Fast is the stronger model overall, scoring 41.4 to 36.4 on the Noometry Index.

Which is cheaper, Grok 4.1 Fast or Grok Build 0.1?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Grok Build 0.1 lists at $1 and $2.

Is Grok 4.1 Fast or Grok Build 0.1 better for coding?

Grok Build 0.1 scores higher on coding benchmarks: 43.1 versus 34.1 in the Noometry coding category.

Which has the bigger context window?

Grok Build 0.1 does, with 256K tokens against 128K.

How many benchmarks do Grok 4.1 Fast and Grok Build 0.1 share?

0 benchmarks have published results for both models. Grok 4.1 Fast has 32 scored results on Noometry and Grok Build 0.1 has 3.

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