Model comparison
Claude Opus 4.1 vs GLM-4.5-Air
Claude Opus 4.1 is the stronger model overall, scoring 41.0 to 38.9 on the Noometry Index. GLM-4.5-Air costs 71× less per token, which makes it the better buy when Claude Opus 4.1's lead doesn't matter for your workload.
Last verified . 20 shared benchmarks.
Summary
- They share 20 benchmarks with published results for both. Claude Opus 4.1 scores higher in 7 categories and GLM-4.5-Air in 1 category; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where GLM-4.5-Air leads 36.2 to 22.3.
- GLM-4.5-Air is cheaper at $0.20 / $1.10 per million input/output tokens, against $15 / $75 for Claude Opus 4.1.
- Claude Opus 4.1 accepts more context: 200K tokens versus 131K.
- GLM-4.5-Air has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 4.1 | GLM-4.5-Air | |
|---|---|---|
| Provider | Anthropic | Z.ai (Zhipu) |
| Noometry Index | 41.0 | 38.9 |
| Released | 2025-08-05 | 2025-07-20 |
| Weights | Proprietary | Open |
| Context window | 200K | 131K |
| Max output | 32K | 98K |
| Input $ / M tokens | $15 | $0.20 |
| Output $ / M tokens | $75 | $1.10 |
| Results tracked | 48 | 27 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Claude Opus 4.1 leads
Claude Opus 4.1: 44.4 (#73), GLM-4.5-Air: 33.3 (#259)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Coding | 1479 | 1397 |
| SWE-bench Verified | 73.3% | — |
| LMArena WebDev | 1390 | — |
| GSO | — | 2.9% |
| WeirdML | 45.9% | — |
| ALE-Bench | 674.77 | — |
| AlgoTune | 1.34 | — |
Agentic & Tool Use Not comparable
Claude Opus 4.1: 35.0 (#41), GLM-4.5-Air: —
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| Terminal-Bench | 38% | — |
| GDPval | 43.6% | — |
| Cybench | 42% | — |
| DeepResearch Bench | 48.3% | — |
| LMArena Search | 1148 | — |
| METR Time Horizons | 66.8% | — |
Reasoning Claude Opus 4.1 leads
Claude Opus 4.1: 32.2 (#76), GLM-4.5-Air: 24.1 (#166)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Hard Prompts | 1443 | 1379 |
| ForecastBench | 62 | 59.2 |
| SimpleBench | 60% | — |
| Kagi LLM Benchmark | — | 43% |
| Chess Puzzles | 7% | — |
| EnigmaEval | 7.2% | — |
| EBR-Bench | 7.9% | — |
| Mystery Game Puzzles | 21% | — |
| DTBench | 80% | — |
| LMCA | 37.1% | — |
| Epoch Capabilities Index | 144.12 | — |
Math GLM-4.5-Air leads
Claude Opus 4.1: 22.3 (#277), GLM-4.5-Air: 36.2 (#170)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Math | 1431 | 1396 |
| FrontierMath (Tiers 1-3) | 12.6% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 68.9% | — |
| Omni-MATH | — | 39.1% |
| FrontierMath (Feb 2025 set) | 7.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Claude Opus 4.1 leads
Claude Opus 4.1: 42.0 (#101), GLM-4.5-Air: 35.0 (#191)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| Humanity's Last Exam | 11.5% | 8.1% |
| Vectara Hallucination Rate | 11.8% | 9.3% |
| LMArena Expert | 1439 | 1370 |
| GPQA Diamond | 77.3% | — |
| MMLU-Pro | — | 76.2% |
| Confabulations | 17.1% | — |
| GPQA (HELM) | — | 59.4% |
Multimodal Not comparable
Claude Opus 4.1: 26.8 (#119), GLM-4.5-Air: —
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| VPCT | 35% | — |
Multilingual Claude Opus 4.1 leads
Claude Opus 4.1: 52.0 (#95), GLM-4.5-Air: 49.1 (#135)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Non-English | 1405 | 1366 |
| LMArena Chinese | 1427 | 1426 |
| LMArena French | 1431 | 1399 |
| LMArena German | 1413 | 1377 |
| LMArena Japanese | 1378 | 1348 |
| LMArena Korean | 1380 | 1308 |
| LMArena Russian | 1422 | 1373 |
| LMArena Spanish | 1448 | 1386 |
Instruction Following Claude Opus 4.1 leads
Claude Opus 4.1: 75.6 (#58), GLM-4.5-Air: 69.6 (#171)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Instruction Following | 1435 | 1354 |
| IFEval | — | 81.2% |
Long Context Claude Opus 4.1 leads
Claude Opus 4.1: 44.5 (#63), GLM-4.5-Air: 41.6 (#135)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Longer Query | 1455 | 1366 |
Writing & Preference Claude Opus 4.1 leads
Claude Opus 4.1: 62.4 (#74), GLM-4.5-Air: 55.9 (#139)
| Benchmark | Claude Opus 4.1 | GLM-4.5-Air |
|---|---|---|
| LMArena Text | 1419 | 1384 |
| LMArena Creative Writing | 1412 | 1343 |
| LMArena Multi-Turn | 1444 | 1371 |
| Short-Story Creative Writing | 84.7% | — |
| WildBench | — | 78.9% |
Frequently asked questions
Is Claude Opus 4.1 better than GLM-4.5-Air?
Claude Opus 4.1 is the stronger model overall, scoring 41.0 to 38.9 on the Noometry Index. GLM-4.5-Air costs 71× less per token, which makes it the better buy when Claude Opus 4.1's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 4.1 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 4.1 lists at $15 and $75.
Is Claude Opus 4.1 or GLM-4.5-Air better for coding?
Claude Opus 4.1 scores higher on coding benchmarks: 44.4 versus 33.3 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 4.1 does, with 200K tokens against 131K.
How many benchmarks do Claude Opus 4.1 and GLM-4.5-Air share?
20 benchmarks have published results for both models. Claude Opus 4.1 has 48 scored results on Noometry and GLM-4.5-Air has 27.