Model comparison

Claude Opus 4.8 vs GLM-4.5-Air

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 38.9 on the Noometry Index. GLM-4.5-Air costs 24× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Last verified . 20 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

GLM-4.5-Air Z.ai (Zhipu)

38.9

Rank #177 Confirmed

Summary

  • They share 20 benchmarks with published results for both. Claude Opus 4.8 scores higher in 8 categories and GLM-4.5-Air in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.8 leads 78.4 to 36.2.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 88.8% for Claude Opus 4.8 and 43% for GLM-4.5-Air.
  • GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.
  • Claude Opus 4.8 accepts more context: 1M tokens versus 131K.
  • GLM-4.5-Air has downloadable open weights; the other is API-only.

Side by side

Claude Opus 4.8 and GLM-4.5-Air specifications
Claude Opus 4.8GLM-4.5-Air
ProviderAnthropicZ.ai (Zhipu)
Noometry Index60.738.9
Released2026-05-282025-07-20
WeightsProprietaryOpen
Context window1M131K
Max output128K98K
Input $ / M tokens$5$0.20
Output $ / M tokens$25$1.10
Results tracked6527

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), GLM-4.5-Air: 33.3 (#259)

Coding benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
GSO47.1%2.9%
LMArena Coding14901397
DeepSWE59%—
FrontierCode46.5%—
LMArena WebDev1556—
SciCode53.5%—
WeirdML82.9%—
ALE-Bench1,564—

Agentic & Tool Use Not comparable

Claude Opus 4.8: 47.6 (#11), GLM-4.5-Air: —

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
LMArena Search1204—
Vending-Bench 25,787—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), GLM-4.5-Air: 24.1 (#166)

Reasoning benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
Kagi LLM Benchmark88.8%43%
LMArena Hard Prompts14821379
ForecastBench59.959.2
ARC-AGI-272.1%—
SimpleBench64.8%—
NYT Connections (extended)91.1%—
ARC-AGI-192.5%—
CritPt20.9%—
Chess Puzzles34%—
EnigmaEval23.5%—
EBR-Bench28.6%—
Mystery Game Puzzles36%—
DTBench94.9%—
LMCA57.5%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
Epoch Capabilities Index158.21—

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.4 (#13), GLM-4.5-Air: 36.2 (#170)

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), GLM-4.5-Air: 35.0 (#191)

Knowledge benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Expert15021370
GPQA Diamond91%—
Humanity's Last Exam—8.1%
SimpleQA Verified53%—
MMLU-Pro—76.2%
Vectara Hallucination Rate—9.3%
GPQA (HELM)—59.4%

Multimodal Not comparable

Claude Opus 4.8: 42.9 (#26), GLM-4.5-Air: —

Multimodal benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Vision1294—
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Claude Opus 4.8 leads

Claude Opus 4.8: 55.2 (#33), GLM-4.5-Air: 49.1 (#135)

Multilingual benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Non-English14501366
LMArena Chinese15071426
LMArena French14811399
LMArena German14721377
LMArena Japanese14401348
LMArena Korean14321308
LMArena Russian14741373
LMArena Spanish14661386

Instruction Following Claude Opus 4.8 leads

Claude Opus 4.8: 77.4 (#24), GLM-4.5-Air: 69.6 (#171)

Instruction Following benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Instruction Following14761354
IFEval—81.2%

Long Context Claude Opus 4.8 leads

Claude Opus 4.8: 45.4 (#35), GLM-4.5-Air: 41.6 (#135)

Long Context benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Longer Query14831366

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), GLM-4.5-Air: 55.9 (#139)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8GLM-4.5-Air
LMArena Text14611384
LMArena Creative Writing14541343
LMArena Multi-Turn14761371
EQ-Bench Creative Writing1840—
WildBench—78.9%
EQ-Bench 41281—

Frequently asked questions

Is Claude Opus 4.8 better than GLM-4.5-Air?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 38.9 on the Noometry Index. GLM-4.5-Air costs 24× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 or GLM-4.5-Air?

GLM-4.5-Air is cheaper. It lists at $0.20 per million input tokens and $1.10 per million output tokens; Claude Opus 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or GLM-4.5-Air better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 33.3 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.8 does, with 1M tokens against 131K.

How many benchmarks do Claude Opus 4.8 and GLM-4.5-Air share?

20 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and GLM-4.5-Air has 27.

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