Noometry

Model comparison

GLM-5.3-Flash vs Grok 4.1 Fast

GLM-5.3-Flash is the stronger model overall, scoring 49.6 to 40.9 on the Noometry Index.

Last verified . 21 shared benchmarks.

GLM-5.3-Flash Z.ai (Zhipu)

49.6

Rank #45 Confirmed

Grok 4.1 Fast xAI

40.9

Rank #131 Confirmed

Summary

  • They share 21 benchmarks with published results for both. GLM-5.3-Flash scores higher in 8 categories and Grok 4.1 Fast in 2 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GLM-5.3-Flash leads 58.4 to 32.6.
  • The biggest single-benchmark swing is ProofBench: 21% for GLM-5.3-Flash and 4% for Grok 4.1 Fast.
  • GLM-5.3-Flash is cheaper at $0.15 / $0.50 per million input/output tokens, against $0.20 / $0.50 for Grok 4.1 Fast.
  • GLM-5.3-Flash accepts more context: 1M tokens versus 128K.
  • GLM-5.3-Flash has downloadable open weights; the other is API-only.

Side by side

GLM-5.3-FlashGrok 4.1 Fast
ProviderZ.ai (Zhipu)xAI
Noometry Index49.640.9
Released2026-08-202025-06-27
WeightsOpenProprietary
Context window1M128K
Max output131K30K
Input $ / M tokens$0.15$0.20
Output $ / M tokens$0.50$0.50
Results tracked3632

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Category by category

Coding GLM-5.3-Flash leads

GLM-5.3-Flash: 53.7 (#26), Grok 4.1 Fast: 33.8 (#236)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena WebDev16141241
LMArena Coding15061411
ALE-Bench303.55394.93
DeepSWE63.4%—
FrontierCode31.8%—
SciCode51.6%—

Agentic & Tool Use Grok 4.1 Fast leads

GLM-5.3-Flash: 34.3 (#41), Grok 4.1 Fast: 36.1 (#35)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
APEX-Agents52.8%—
Berkeley Function Calling Leaderboard—69.6%
τ²-bench Banking—13.1%
GDP.pdf14%—
LMArena Search—1171
Vending-Bench 2—1,107

Reasoning Grok 4.1 Fast leads

GLM-5.3-Flash: 31.7 (#69), Grok 4.1 Fast: 42.3 (#45)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Hard Prompts14901407
SimpleBench—56%
NYT Connections (extended)—87.4%
CritPt15.4%—
Chess Puzzles14%—
Mystery Game Puzzles8%—
DTBench—87.7%
Surface Evolver Bench52.5%—
Bench to the Future 30.15—
Epoch Capabilities Index151.9—
ForecastBench—61

Math GLM-5.3-Flash leads

GLM-5.3-Flash: 53.1 (#38), Grok 4.1 Fast: 30.9 (#201)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
ProofBench21%4%
LMArena Math14991408
FrontierMath (Tiers 1-3)55.8%—
FrontierMath Tier 417.1%—
MathArena Final-Answer Competitions—60.9%
OTIS Mock AIME 2024-202593.9%—

Knowledge GLM-5.3-Flash leads

GLM-5.3-Flash: 58.4 (#33), Grok 4.1 Fast: 32.6 (#203)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Expert15121398
GPQA Diamond90.2%—
Vectara Hallucination Rate—17.8%

Multimodal GLM-5.3-Flash leads

GLM-5.3-Flash: 42.6 (#25), Grok 4.1 Fast: 36.3 (#71)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Vision13041201

Multilingual GLM-5.3-Flash leads

GLM-5.3-Flash: 56.2 (#24), Grok 4.1 Fast: 51.1 (#110)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Non-English14621391
LMArena Chinese15291441
LMArena French14951416
LMArena German14571404
LMArena Japanese14201347
LMArena Korean14431361
LMArena Russian14721387
LMArena Spanish14711411

Instruction Following GLM-5.3-Flash leads

GLM-5.3-Flash: 77.8 (#17), Grok 4.1 Fast: 72.8 (#127)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Instruction Following14801376

Long Context GLM-5.3-Flash leads

GLM-5.3-Flash: 45.3 (#41), Grok 4.1 Fast: 42.4 (#121)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Longer Query14791390

Writing & Preference GLM-5.3-Flash leads

GLM-5.3-Flash: 65.4 (#49), Grok 4.1 Fast: 57.4 (#126)

BenchmarkGLM-5.3-FlashGrok 4.1 Fast
LMArena Text14711408
LMArena Creative Writing14401394
LMArena Multi-Turn14711389
EQ-Bench Creative Writing—1327

Frequently asked questions

Is GLM-5.3-Flash better than Grok 4.1 Fast?

GLM-5.3-Flash is the stronger model overall, scoring 49.6 to 40.9 on the Noometry Index.

Which is cheaper, GLM-5.3-Flash or Grok 4.1 Fast?

GLM-5.3-Flash is cheaper. It lists at $0.15 per million input tokens and $0.50 per million output tokens; Grok 4.1 Fast lists at $0.20 and $0.50.

Is GLM-5.3-Flash or Grok 4.1 Fast better for coding?

GLM-5.3-Flash scores higher on coding benchmarks: 53.7 versus 33.8 in the Noometry coding category.

Which has the bigger context window?

GLM-5.3-Flash does, with 1M tokens against 128K.

How many benchmarks do GLM-5.3-Flash and Grok 4.1 Fast share?

21 benchmarks have published results for both models. GLM-5.3-Flash has 36 scored results on Noometry and Grok 4.1 Fast has 32.

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