Noometry

Model comparison

GLM-5.3-Flash vs GPT-5.1-Codex-mini

GLM-5.3-Flash has enough public results to be ranked (#45); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Last verified . 1 shared benchmarks.

GLM-5.3-Flash Z.ai (Zhipu)

49.6

Rank #45 Confirmed

GPT-5.1-Codex-mini OpenAI

36.9

Unranked Sparse

Summary

  • They share 1 benchmark with published results for both. GLM-5.3-Flash scores higher in 1 category and GPT-5.1-Codex-mini in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in coding, where GLM-5.3-Flash leads 53.7 to 31.4.
  • GLM-5.3-Flash is cheaper at $0.15 / $0.50 per million input/output tokens, against $0.25 / $2 for GPT-5.1-Codex-mini.
  • GLM-5.3-Flash accepts more context: 1M tokens versus 400K.
  • GLM-5.3-Flash has downloadable open weights; the other is API-only.

Side by side

GLM-5.3-FlashGPT-5.1-Codex-mini
ProviderZ.ai (Zhipu)OpenAI
Noometry Index49.636.9
Released2026-08-202025-11-12
WeightsOpenProprietary
Context window1M400K
Max output131K128K
Input $ / M tokens$0.15$0.25
Output $ / M tokens$0.50$2
Results tracked362

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Category by category

Coding GLM-5.3-Flash leads

GLM-5.3-Flash: 53.7 (#26), GPT-5.1-Codex-mini: 31.4

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena WebDev16141244
DeepSWE63.4%—
FrontierCode31.8%—
SciCode51.6%—
LMArena Coding1506—
ALE-Bench303.55—

Agentic & Tool Use GPT-5.1-Codex-mini leads

GLM-5.3-Flash: 34.3 (#41), GPT-5.1-Codex-mini: 38.3

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
Terminal-Bench—61.6%
APEX-Agents52.8%—
GDP.pdf14%—

Reasoning Not comparable

GLM-5.3-Flash: 31.7 (#69), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
CritPt15.4%—
Chess Puzzles14%—
LMArena Hard Prompts1490—
Mystery Game Puzzles8%—
Surface Evolver Bench52.5%—
Bench to the Future 30.15—
Epoch Capabilities Index151.9—

Math Not comparable

GLM-5.3-Flash: 53.1 (#38), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
FrontierMath (Tiers 1-3)55.8%—
FrontierMath Tier 417.1%—
OTIS Mock AIME 2024-202593.9%—
ProofBench21%—
LMArena Math1499—

Knowledge Not comparable

GLM-5.3-Flash: 58.4 (#33), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
GPQA Diamond90.2%—
LMArena Expert1512—

Multimodal Not comparable

GLM-5.3-Flash: 42.6 (#25), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena Vision1304—

Multilingual Not comparable

GLM-5.3-Flash: 56.2 (#24), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena Non-English1462—
LMArena Chinese1529—
LMArena French1495—
LMArena German1457—
LMArena Japanese1420—
LMArena Korean1443—
LMArena Russian1472—
LMArena Spanish1471—

Instruction Following Not comparable

GLM-5.3-Flash: 77.8 (#17), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena Instruction Following1480—

Long Context Not comparable

GLM-5.3-Flash: 45.3 (#41), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena Longer Query1479—

Writing & Preference Not comparable

GLM-5.3-Flash: 65.4 (#49), GPT-5.1-Codex-mini: —

BenchmarkGLM-5.3-FlashGPT-5.1-Codex-mini
LMArena Text1471—
LMArena Creative Writing1440—
LMArena Multi-Turn1471—

Frequently asked questions

Is GLM-5.3-Flash better than GPT-5.1-Codex-mini?

GLM-5.3-Flash has enough public results to be ranked (#45); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Which is cheaper, GLM-5.3-Flash or GPT-5.1-Codex-mini?

GLM-5.3-Flash is cheaper. It lists at $0.15 per million input tokens and $0.50 per million output tokens; GPT-5.1-Codex-mini lists at $0.25 and $2.

Is GLM-5.3-Flash or GPT-5.1-Codex-mini better for coding?

GLM-5.3-Flash scores higher on coding benchmarks: 53.7 versus 31.4 in the Noometry coding category.

Which has the bigger context window?

GLM-5.3-Flash does, with 1M tokens against 400K.

How many benchmarks do GLM-5.3-Flash and GPT-5.1-Codex-mini share?

1 benchmark has published results for both models. GLM-5.3-Flash has 36 scored results on Noometry and GPT-5.1-Codex-mini has 2.

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