Noometry

Model comparison

GLM-5.3-Flash vs GPT-5.5 Instant

GLM-5.3-Flash is the stronger model overall, scoring 51.8 to 42.7 on the Noometry Index.

Last verified . 26 shared benchmarks.

GLM-5.3-Flash Z.ai (Zhipu)

51.8

Rank #41 Confirmed

GPT-5.5 Instant OpenAI

42.7

Rank #110 Confirmed

Summary

  • They share 26 benchmarks with published results for both. GLM-5.3-Flash scores higher in 9 categories and GPT-5.5 Instant in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GLM-5.3-Flash leads 53.3 to 26.5.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 55.8% for GLM-5.3-Flash and 26.3% for GPT-5.5 Instant.
  • GLM-5.3-Flash has downloadable open weights; the other is API-only.

Side by side

GLM-5.3-FlashGPT-5.5 Instant
ProviderZ.ai (Zhipu)OpenAI
Noometry Index51.842.7
Released2026-08-202026-05-05
WeightsOpenProprietary
Context window1M—
Max output131K—
Input $ / M tokens$0.15—
Output $ / M tokens$0.50—
Results tracked4027

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Category by category

Coding GLM-5.3-Flash leads

GLM-5.3-Flash: 53.1 (#31), GPT-5.5 Instant: 44.3 (#74)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
SciCode51.6%48.6%
LMArena Coding15081433
DeepSWE63.4%—
FrontierCode31.8%—
CursorBench36.8%—
LMArena WebDev1609—
FrontierSWE18.1%—
ALE-Bench303.55—

Agentic & Tool Use Not comparable

GLM-5.3-Flash: 34.2 (#47), GPT-5.5 Instant: —

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
APEX-Agents52.8%—
GDP.pdf14%—

Reasoning GLM-5.3-Flash leads

GLM-5.3-Flash: 48.0 (#42), GPT-5.5 Instant: 24.9 (#155)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
CritPt15.4%0%
Chess Puzzles14%12%
LMArena Hard Prompts14911426
Epoch Capabilities Index151.88142.52
ARC-AGI-265.8%—
ARC-AGI-191%—
Mystery Game Puzzles8%—
Surface Evolver Bench52.5%—
Bench to the Future 30.15—

Math GLM-5.3-Flash leads

GLM-5.3-Flash: 53.3 (#47), GPT-5.5 Instant: 26.5 (#259)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
FrontierMath (Tiers 1-3)55.8%26.3%
FrontierMath Tier 417.1%2.4%
OTIS Mock AIME 2024-202593.9%68.1%
LMArena Math15001420
ProofBench21%—

Knowledge GLM-5.3-Flash leads

GLM-5.3-Flash: 58.4 (#36), GPT-5.5 Instant: 48.9 (#74)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
GPQA Diamond90.2%82.5%
LMArena Expert15131409

Multimodal GLM-5.3-Flash leads

GLM-5.3-Flash: 42.8 (#27), GPT-5.5 Instant: 40.0 (#52)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
LMArena Vision12961250
LMArena Document—1403

Multilingual GLM-5.3-Flash leads

GLM-5.3-Flash: 56.0 (#25), GPT-5.5 Instant: 52.8 (#80)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
LMArena Non-English14621417
LMArena Chinese15271456
LMArena French14961428
LMArena German14701411
LMArena Japanese14291408
LMArena Korean14461392
LMArena Russian14691431
LMArena Spanish14711429

Instruction Following GLM-5.3-Flash leads

GLM-5.3-Flash: 77.5 (#20), GPT-5.5 Instant: 74.2 (#100)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
LMArena Instruction Following14781406

Long Context GLM-5.3-Flash leads

GLM-5.3-Flash: 45.4 (#39), GPT-5.5 Instant: 43.4 (#96)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
LMArena Longer Query14821422

Writing & Preference GLM-5.3-Flash leads

GLM-5.3-Flash: 65.3 (#50), GPT-5.5 Instant: 61.8 (#85)

BenchmarkGLM-5.3-FlashGPT-5.5 Instant
LMArena Text14711419
LMArena Creative Writing14421419
LMArena Multi-Turn14671433

Frequently asked questions

Is GLM-5.3-Flash better than GPT-5.5 Instant?

GLM-5.3-Flash is the stronger model overall, scoring 51.8 to 42.7 on the Noometry Index.

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

GLM-5.3-Flash scores higher on coding benchmarks: 53.1 versus 44.3 in the Noometry coding category.

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

26 benchmarks have published results for both models. GLM-5.3-Flash has 40 scored results on Noometry and GPT-5.5 Instant has 27.

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