Model comparison

GLM-4.5-Air vs GPT-5 Mini

GPT-5 Mini is the stronger model overall, scoring 41.8 to 38.9 on the Noometry Index. GLM-4.5-Air costs 1.6× less per token, which makes it the better buy when GPT-5 Mini's lead doesn't matter for your workload.

Last verified . 26 shared benchmarks.

GLM-4.5-Air Z.ai (Zhipu)

38.9

Rank #177 Confirmed

GPT-5 Mini OpenAI

41.8

Rank #128 Confirmed

Summary

  • They share 26 benchmarks with published results for both. GLM-4.5-Air scores higher in 3 categories and GPT-5 Mini in 5 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GPT-5 Mini leads 45.6 to 35.0.
  • The biggest single-benchmark swing is Omni-MATH: 39.1% for GLM-4.5-Air and 72.2% for GPT-5 Mini.
  • GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $0.25 / $2 for GPT-5 Mini.
  • GPT-5 Mini accepts more context: 400K tokens versus 131K.
  • GLM-4.5-Air has downloadable open weights; the other is API-only.

Side by side

GLM-4.5-Air and GPT-5 Mini specifications
GLM-4.5-AirGPT-5 Mini
ProviderZ.ai (Zhipu)OpenAI
Noometry Index38.941.8
Released2025-07-202025-08-07
WeightsOpenProprietary
Context window131K400K
Max output98K128K
Input $ / M tokens$0.20$0.25
Output $ / M tokens$1.10$2
Results tracked2760

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Category by category

Coding GPT-5 Mini leads

GLM-4.5-Air: 33.3 (#259), GPT-5 Mini: 40.1 (#146)

Coding benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
LMArena Coding13971406
SWE-bench Verified—64.7%
SWE-bench Verified (bash only)—59.8%
SWE-bench Multilingual—39.7%
SciCode—39.2%
GSO2.9%—
WeirdML—52.7%
ALE-Bench—799.77
AlgoTune—1.38

Agentic & Tool Use Not comparable

GLM-4.5-Air: —, GPT-5 Mini: 31.1 (#70)

Agentic & Tool Use benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
Terminal-Bench—34.8%
Berkeley Function Calling Leaderboard—55.5%
Vending-Bench 2—-31.18

Reasoning Too close to call

GLM-4.5-Air: 24.1 (#166), GPT-5 Mini: 23.9 (#168)

Reasoning benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
Kagi LLM Benchmark43%70.3%
LMArena Hard Prompts13791380
ForecastBench59.261
ARC-AGI-2—4.4%
ARC-AGI-1—54.3%
CritPt—0%
Chess Puzzles—30%
EnigmaEval—8.2%
Mystery Game Puzzles—10%
DTBench—80.5%
LMCA—34.2%
Epoch Capabilities Index—145.52

Math GPT-5 Mini leads

GLM-4.5-Air: 36.2 (#170), GPT-5 Mini: 46.7 (#69)

Math benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
Omni-MATH39.1%72.2%
LMArena Math13961378
FrontierMath (Tiers 1-3)—46.7%
FrontierMath Tier 4—12.2%
OTIS Mock AIME 2024-2025—86.7%
ProofBench—9%
MATH Level 5—97.8%
FrontierMath (Feb 2025 set)—27.2%
FrontierMath Tier 4 (v1)—6.3%

Knowledge GPT-5 Mini leads

GLM-4.5-Air: 35.0 (#191), GPT-5 Mini: 45.6 (#86)

Knowledge benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
Humanity's Last Exam8.1%19.4%
MMLU-Pro76.2%83.5%
Vectara Hallucination Rate9.3%12.9%
GPQA (HELM)59.4%75.6%
LMArena Expert13701379
GPQA Diamond—75%
SimpleQA Verified—21.6%
Confabulations—13.3%

Multimodal Not comparable

GLM-4.5-Air: —, GPT-5 Mini: 35.6 (#85)

Multimodal benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
LMArena Vision—1202
VPCT—40.2%

Multilingual Too close to call

GLM-4.5-Air: 49.1 (#135), GPT-5 Mini: 48.9 (#137)

Multilingual benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
LMArena Non-English13661363
LMArena Chinese14261385
LMArena French13991386
LMArena German13771366
LMArena Japanese13481341
LMArena Korean13081308
LMArena Russian13731362
LMArena Spanish13861355

Instruction Following GPT-5 Mini leads

GLM-4.5-Air: 69.6 (#171), GPT-5 Mini: 76.2 (#46)

Instruction Following benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
IFEval81.2%92.7%
LMArena Instruction Following13541357

Long Context Too close to call

GLM-4.5-Air: 41.6 (#135), GPT-5 Mini: 41.9 (#132)

Long Context benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
LMArena Longer Query13661355
Fiction.LiveBench—69.4%

Writing & Preference Too close to call

GLM-4.5-Air: 55.9 (#139), GPT-5 Mini: 55.2 (#148)

Writing & Preference benchmarks
BenchmarkGLM-4.5-AirGPT-5 Mini
LMArena Text13841373
LMArena Creative Writing13431325
WildBench78.9%85.5%
LMArena Multi-Turn13711363
Short-Story Creative Writing—83.1%
EQ-Bench Creative Writing—1313

Frequently asked questions

Is GLM-4.5-Air better than GPT-5 Mini?

GPT-5 Mini is the stronger model overall, scoring 41.8 to 38.9 on the Noometry Index. GLM-4.5-Air costs 1.6× less per token, which makes it the better buy when GPT-5 Mini's lead doesn't matter for your workload.

Which is cheaper, GLM-4.5-Air or GPT-5 Mini?

GLM-4.5-Air is cheaper. It lists at $0.20 per million input tokens and $1.10 per million output tokens; GPT-5 Mini lists at $0.25 and $2.

Is GLM-4.5-Air or GPT-5 Mini better for coding?

GPT-5 Mini scores higher on coding benchmarks: 40.1 versus 33.3 in the Noometry coding category.

Which has the bigger context window?

GPT-5 Mini does, with 400K tokens against 131K.

How many benchmarks do GLM-4.5-Air and GPT-5 Mini share?

26 benchmarks have published results for both models. GLM-4.5-Air has 27 scored results on Noometry and GPT-5 Mini has 60.

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