Noometry

Model comparison

GLM-4.5 vs GPT-5.3 Codex

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 42.0 on the Noometry Index. GLM-4.5 costs 4.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Last verified . 2 shared benchmarks.

GLM-4.5 Z.ai (Zhipu)

42.0

Rank #122 Confirmed

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

Summary

  • They share 2 benchmarks with published results for both. GLM-4.5 scores higher in 0 categories and GPT-5.3 Codex in 1 category; one gap is clear of the uncertainty.
  • The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 41.4.
  • The biggest single-benchmark swing is WeirdML: 40.6% for GLM-4.5 and 79.3% for GPT-5.3 Codex.
  • GLM-4.5 is cheaper at $0.60 / $2.20 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
  • GPT-5.3 Codex accepts more context: 400K tokens versus 131K.
  • GLM-4.5 has downloadable open weights; the other is API-only.

Side by side

GLM-4.5GPT-5.3 Codex
ProviderZ.ai (Zhipu)OpenAI
Noometry Index42.045.8
Released2025-07-272026-02-05
WeightsOpenProprietary
Context window131K400K
Max output98K128K
Input $ / M tokens$0.60$1.75
Output $ / M tokens$2.20$14
Results tracked278

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Category by category

Coding GPT-5.3 Codex leads

GLM-4.5: 41.4 (#125), GPT-5.3 Codex: 48.6 (#56)

BenchmarkGLM-4.5GPT-5.3 Codex
WeirdML40.6%79.3%
ALE-Bench344.821,655
SWE-bench Verified—74.8%
SWE-bench Verified (bash only)54.2%—
LMArena WebDev—1409
LMArena Coding1434—
AlgoTune1.52—

Agentic & Tool Use Not comparable

GLM-4.5: —, GPT-5.3 Codex: 48.0 (#9)

BenchmarkGLM-4.5GPT-5.3 Codex
Terminal-Bench—78.4%
METR Time Horizons—74.5%
Vending-Bench 2—5,940

Reasoning Not comparable

GLM-4.5: 28.6 (#100), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
Kagi LLM Benchmark57.9%—
LMArena Hard Prompts1429—
Epoch Capabilities Index—156.77

Math Not comparable

GLM-4.5: 39.0 (#116), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
LMArena Math1427—

Knowledge Not comparable

GLM-4.5: 35.9 (#179), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
Humanity's Last Exam8.3%—
Confabulations11.3%—
LMArena Expert1433—

Multilingual Not comparable

GLM-4.5: 52.8 (#77), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
LMArena Non-English1417—
LMArena Chinese1465—
LMArena French1418—
LMArena German1407—
LMArena Japanese1415—
LMArena Korean1380—
LMArena Russian1414—
LMArena Spanish1454—

Instruction Following Not comparable

GLM-4.5: 74.1 (#104), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
LMArena Instruction Following1404—

Long Context Not comparable

GLM-4.5: 38.2 (#201), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
Fiction.LiveBench58.3%—
LMArena Longer Query1412—

Writing & Preference Not comparable

GLM-4.5: 57.5 (#127), GPT-5.3 Codex: —

BenchmarkGLM-4.5GPT-5.3 Codex
LMArena Text1430—
LMArena Creative Writing1395—
Short-Story Creative Writing73.4%—
EQ-Bench Creative Writing1343—
LMArena Multi-Turn1415—

Frequently asked questions

Is GLM-4.5 better than GPT-5.3 Codex?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 42.0 on the Noometry Index. GLM-4.5 costs 4.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Which is cheaper, GLM-4.5 or GPT-5.3 Codex?

GLM-4.5 is cheaper. It lists at $0.60 per million input tokens and $2.20 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

Is GLM-4.5 or GPT-5.3 Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 41.4 in the Noometry coding category.

Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 131K.

How many benchmarks do GLM-4.5 and GPT-5.3 Codex share?

2 benchmarks have published results for both models. GLM-4.5 has 27 scored results on Noometry and GPT-5.3 Codex has 8.

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