Noometry

Model comparison

Claude Sonnet 5.5 vs GLM-4.5-Air

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 38.9 on the Noometry Index. GLM-4.5-Air costs 9.4× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

Last verified . 12 shared benchmarks.

Claude Sonnet 5.5 Anthropic

61.9

Rank #10 Confirmed

GLM-4.5-Air Z.ai (Zhipu)

38.9

Rank #177 Confirmed

Summary

  • They share 12 benchmarks with published results for both. Claude Sonnet 5.5 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 Sonnet 5.5 leads 87.9 to 36.2.
  • GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.5.
  • Claude Sonnet 5.5 accepts more context: 1M tokens versus 131K.
  • GLM-4.5-Air has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 5.5GLM-4.5-Air
ProviderAnthropicZ.ai (Zhipu)
Noometry Index61.938.9
Released2026-09-282025-07-20
WeightsProprietaryOpen
Context window1M131K
Max output128K98K
Input $ / M tokens$2$0.20
Output $ / M tokens$10$1.10
Results tracked3227

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 67.3 (#6), GLM-4.5-Air: 33.3 (#259)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Coding15131397
FrontierCode52.1%—
CursorBench55.5%—
LMArena WebDev1774—
FrontierSWE61.9%—
SciCode61%—
GSO—2.9%
ALE-Bench1,819—

Agentic & Tool Use Not comparable

Claude Sonnet 5.5: 45.0 (#16), GLM-4.5-Air: —

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
APEX-Agents75.5%—

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 54.0 (#28), GLM-4.5-Air: 24.1 (#166)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Hard Prompts14951379
Kagi LLM Benchmark—43%
NYT Connections (extended)80.5%—
CritPt31.4%—
Mystery Game Puzzles65%—
Epoch Capabilities Index165.03—
ForecastBench—59.2

Math Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 87.9 (#6), GLM-4.5-Air: 36.2 (#170)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Math15101396
FrontierMath (Tiers 1-3)88.8%—
FrontierMath Tier 480.5%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
Omni-MATH—39.1%
FrontierMath Erdős2.9%—

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#12), GLM-4.5-Air: 35.0 (#191)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Expert15401370
GPQA Diamond95.6%—
Humanity's Last Exam—8.1%
SimpleQA Verified46.5%—
MMLU-Pro—76.2%
Vectara Hallucination Rate—9.3%
GPQA (HELM)—59.4%

Multimodal Not comparable

Claude Sonnet 5.5: 51.5 (#6), GLM-4.5-Air: —

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Vision1289—
Furniture Assembly75%—

Multilingual Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 55.3 (#30), GLM-4.5-Air: 49.1 (#135)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Non-English14521366
LMArena Chinese15221426
LMArena Russian14511373
LMArena French—1399
LMArena German—1377
LMArena Japanese—1348
LMArena Korean—1308
LMArena Spanish—1386

Instruction Following Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 78.3 (#11), GLM-4.5-Air: 69.6 (#171)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Instruction Following14951354
IFEval—81.2%

Long Context Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.9 (#28), GLM-4.5-Air: 41.6 (#135)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Longer Query14981366

Writing & Preference Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#40), GLM-4.5-Air: 55.9 (#139)

BenchmarkClaude Sonnet 5.5GLM-4.5-Air
LMArena Text14711384
LMArena Creative Writing14651343
LMArena Multi-Turn14741371
WildBench—78.9%

Frequently asked questions

Is Claude Sonnet 5.5 better than GLM-4.5-Air?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 38.9 on the Noometry Index. GLM-4.5-Air costs 9.4× less per token, which makes it the better buy when Claude Sonnet 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 5.5 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 Sonnet 5.5 lists at $2 and $10.

Is Claude Sonnet 5.5 or GLM-4.5-Air better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 33.3 in the Noometry coding category.

Which has the bigger context window?

Claude Sonnet 5.5 does, with 1M tokens against 131K.

How many benchmarks do Claude Sonnet 5.5 and GLM-4.5-Air share?

12 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and GLM-4.5-Air has 27.

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