Noometry

Model comparison

GLM-5.3 vs GPT-5.5 Instant

GLM-5.3 is the stronger model overall, scoring 54.6 to 42.5 on the Noometry Index.

Last verified . 25 shared benchmarks.

GLM-5.3 Z.ai (Zhipu)

54.6

Rank #25 Confirmed

GPT-5.5 Instant OpenAI

42.5

Rank #99 Confirmed

Summary

  • They share 25 benchmarks with published results for both. GLM-5.3 scores higher in 8 categories and GPT-5.5 Instant in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GLM-5.3 leads 62.1 to 26.1.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 68.8% for GLM-5.3 and 26.3% for GPT-5.5 Instant.
  • GLM-5.3 has downloadable open weights; the other is API-only.

Side by side

GLM-5.3GPT-5.5 Instant
ProviderZ.ai (Zhipu)OpenAI
Noometry Index54.642.5
Released2026-08-142026-05-05
WeightsOpenProprietary
Context window1M—
Max output131K—
Input $ / M tokens$1.40—
Output $ / M tokens$4.40—
Results tracked4127

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Category by category

Coding GLM-5.3 leads

GLM-5.3: 59.0 (#12), GPT-5.5 Instant: 43.7 (#73)

BenchmarkGLM-5.3GPT-5.5 Instant
SciCode59%48.6%
LMArena Coding14991433
DeepSWE69%—
FrontierCode40.1%—
LMArena WebDev1623—
FrontierSWE30.2%—
WeirdML75.4%—
ALE-Bench1,317—

Agentic & Tool Use Not comparable

GLM-5.3: 36.3 (#34), GPT-5.5 Instant: —

BenchmarkGLM-5.3GPT-5.5 Instant
APEX-Agents56.6%—
Vending-Bench 28,164—

Reasoning GLM-5.3 leads

GLM-5.3: 45.2 (#42), GPT-5.5 Instant: 24.2 (#149)

BenchmarkGLM-5.3GPT-5.5 Instant
CritPt19.1%0%
Chess Puzzles21%12%
LMArena Hard Prompts14911426
Epoch Capabilities Index155.56142.48
NYT Connections (extended)74.2%—
Mystery Game Puzzles33%—
DTBench87.7%—
LMCA55.5%—
Bench to the Future 30.15—

Math GLM-5.3 leads

GLM-5.3: 62.1 (#27), GPT-5.5 Instant: 26.1 (#241)

BenchmarkGLM-5.3GPT-5.5 Instant
FrontierMath (Tiers 1-3)68.8%26.3%
FrontierMath Tier 429.3%2.4%
OTIS Mock AIME 2024-202591.1%68.1%
LMArena Math14931420
ProofBench49%—

Knowledge GLM-5.3 leads

GLM-5.3: 58.3 (#34), GPT-5.5 Instant: 48.9 (#68)

BenchmarkGLM-5.3GPT-5.5 Instant
GPQA Diamond90.9%82.5%
LMArena Expert15121409
SimpleQA Verified41%—

Multimodal Not comparable

GLM-5.3: —, GPT-5.5 Instant: 39.3 (#48)

BenchmarkGLM-5.3GPT-5.5 Instant
LMArena Vision—1250
LMArena Document—1403

Multilingual GLM-5.3 leads

GLM-5.3: 55.9 (#27), GPT-5.5 Instant: 53.0 (#76)

BenchmarkGLM-5.3GPT-5.5 Instant
LMArena Non-English14571417
LMArena Chinese15231457
LMArena French14991428
LMArena German15051410
LMArena Japanese14381408
LMArena Korean14781393
LMArena Russian14601430
LMArena Spanish14441430

Instruction Following GLM-5.3 leads

GLM-5.3: 77.8 (#15), GPT-5.5 Instant: 74.4 (#94)

BenchmarkGLM-5.3GPT-5.5 Instant
LMArena Instruction Following14811407

Long Context GLM-5.3 leads

GLM-5.3: 45.5 (#32), GPT-5.5 Instant: 43.4 (#92)

BenchmarkGLM-5.3GPT-5.5 Instant
LMArena Longer Query14851422

Writing & Preference GLM-5.3 leads

GLM-5.3: 75.9 (#6), GPT-5.5 Instant: 62.0 (#81)

BenchmarkGLM-5.3GPT-5.5 Instant
LMArena Text14731419
LMArena Creative Writing14591420
LMArena Multi-Turn14731434
EQ-Bench Creative Writing2075—

Frequently asked questions

Is GLM-5.3 better than GPT-5.5 Instant?

GLM-5.3 is the stronger model overall, scoring 54.6 to 42.5 on the Noometry Index.

Is GLM-5.3 or GPT-5.5 Instant better for coding?

GLM-5.3 scores higher on coding benchmarks: 59.0 versus 43.7 in the Noometry coding category.

How many benchmarks do GLM-5.3 and GPT-5.5 Instant share?

25 benchmarks have published results for both models. GLM-5.3 has 41 scored results on Noometry and GPT-5.5 Instant has 27.

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