Model comparison
Claude Opus 4.8 vs GLM-5.1
Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 47.8 on the Noometry Index. GLM-5.1 costs 4.7× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.
Last verified . 38 shared benchmarks.
Summary
- They share 38 benchmarks with published results for both. Claude Opus 4.8 scores higher in 9 categories and GLM-5.1 in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 4.8 leads 78.4 to 49.7.
- The biggest single-benchmark swing is GBAEval: 70.9% for Claude Opus 4.8 and 0% for GLM-5.1.
- GLM-5.1 is cheaper at $1.40 / $4.40 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.
- Claude Opus 4.8 accepts more context: 1M tokens versus 200K.
- GLM-5.1 has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 4.8 | GLM-5.1 | |
|---|---|---|
| Provider | Anthropic | Z.ai (Zhipu) |
| Noometry Index | 60.7 | 47.8 |
| Released | 2026-05-28 | 2026-04-07 |
| Weights | Proprietary | Open |
| Context window | 1M | 200K |
| Max output | 128K | 131K |
| Input $ / M tokens | $5 | $1.40 |
| Output $ / M tokens | $25 | $4.40 |
| Results tracked | 65 | 41 |
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Category by category
Coding Claude Opus 4.8 leads
Claude Opus 4.8: 59.9 (#12), GLM-5.1: 48.7 (#55)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena WebDev | 1556 | 1508 |
| SciCode | 53.5% | 43.8% |
| WeirdML | 82.9% | 57.1% |
| LMArena Coding | 1490 | 1485 |
| ALE-Bench | 1,564 | 887.1 |
| SWE-bench Verified | — | 74.2% |
| DeepSWE | 59% | — |
| FrontierCode | 46.5% | — |
| GSO | 47.1% | — |
Agentic & Tool Use Claude Opus 4.8 leads
Claude Opus 4.8: 47.6 (#11), GLM-5.1: 24.9 (#113)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| APEX-Agents | 48.9% | 40.9% |
| GBAEval | 70.9% | 0% |
| Vending-Bench 2 | 5,787 | 5,634 |
| OSWorld 2.0 | 20.6% | — |
| Remote Labor Index | 8.3% | — |
| τ²-bench Banking | 39.7% | — |
| DeepResearch Bench | 50.2% | — |
| PostTrainBench | 33.8% | — |
| ExploitBench | — | 18.1% |
| GDP.pdf | 24% | — |
| LMArena Search | 1204 | — |
Reasoning Claude Opus 4.8 leads
Claude Opus 4.8: 64.7 (#16), GLM-5.1: 39.1 (#60)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| SimpleBench | 64.8% | 55.1% |
| NYT Connections (extended) | 91.1% | 77.7% |
| CritPt | 20.9% | 4.6% |
| Chess Puzzles | 34% | 19% |
| LMArena Hard Prompts | 1482 | 1472 |
| Epoch Capabilities Index | 158.21 | 149.84 |
| ARC-AGI-2 | 72.1% | — |
| Kagi LLM Benchmark | 88.8% | — |
| ARC-AGI-1 | 92.5% | — |
| EnigmaEval | 23.5% | — |
| Thematic Generalization | — | 69.8% |
| EBR-Bench | 28.6% | — |
| Mystery Game Puzzles | 36% | — |
| DTBench | 94.9% | — |
| LMCA | 57.5% | — |
| Surface Evolver Bench | 87.5% | — |
| Bench to the Future 3 | 0.14 | — |
| ForecastBench | 59.9 | — |
Math Claude Opus 4.8 leads
Claude Opus 4.8: 78.4 (#13), GLM-5.1: 49.7 (#60)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 80% | 36.8% |
| MathArena Final-Answer Competitions | 91.8% | 67.1% |
| OTIS Mock AIME 2024-2025 | 98.3% | 93.3% |
| ProofBench | 69% | 22.2% |
| LMArena Math | 1487 | 1473 |
| FrontierMath (Feb 2025 set) | 47.2% | 33.4% |
| FrontierMath Tier 4 (v1) | 31.3% | 12.5% |
| FrontierMath Tier 4 | 56.1% | — |
Knowledge Claude Opus 4.8 leads
Claude Opus 4.8: 61.3 (#29), GLM-5.1: 54.9 (#50)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| GPQA Diamond | 91% | 89.9% |
| SimpleQA Verified | 53% | 34% |
| LMArena Expert | 1502 | 1476 |
Multimodal Not comparable
Claude Opus 4.8: 42.9 (#26), GLM-5.1: —
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena Vision | 1294 | — |
| Blueprint-Bench 2 | 14.5% | — |
| Furniture Assembly | 42.5% | — |
| LMArena Document | 1475 | — |
Multilingual Too close to call
Claude Opus 4.8: 55.2 (#33), GLM-5.1: 55.0 (#36)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena Non-English | 1450 | 1447 |
| LMArena Chinese | 1507 | 1515 |
| LMArena French | 1481 | 1474 |
| LMArena German | 1472 | 1465 |
| LMArena Japanese | 1440 | 1434 |
| LMArena Korean | 1432 | 1418 |
| LMArena Russian | 1474 | 1454 |
| LMArena Spanish | 1466 | 1469 |
Instruction Following Claude Opus 4.8 leads
Claude Opus 4.8: 77.4 (#24), GLM-5.1: 76.3 (#42)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena Instruction Following | 1476 | 1451 |
Long Context Too close to call
Claude Opus 4.8: 45.4 (#35), GLM-5.1: 44.9 (#53)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena Longer Query | 1483 | 1466 |
Writing & Preference Claude Opus 4.8 leads
Claude Opus 4.8: 72.0 (#16), GLM-5.1: 66.9 (#31)
| Benchmark | Claude Opus 4.8 | GLM-5.1 |
|---|---|---|
| LMArena Text | 1461 | 1461 |
| LMArena Creative Writing | 1454 | 1453 |
| EQ-Bench Creative Writing | 1840 | 1592 |
| LMArena Multi-Turn | 1476 | 1472 |
| EQ-Bench 4 | 1281 | — |
Frequently asked questions
Is Claude Opus 4.8 better than GLM-5.1?
Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 47.8 on the Noometry Index. GLM-5.1 costs 4.7× 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-5.1?
GLM-5.1 is cheaper. It lists at $1.40 per million input tokens and $4.40 per million output tokens; Claude Opus 4.8 lists at $5 and $25.
Is Claude Opus 4.8 or GLM-5.1 better for coding?
Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 48.7 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 4.8 does, with 1M tokens against 200K.
How many benchmarks do Claude Opus 4.8 and GLM-5.1 share?
38 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and GLM-5.1 has 41.