Claude Opus 5.5 vs GLM 5.3
Claude Opus 5.5 
GLM 5.3 Verdict
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 65.4.
- Claude Opus 5.5 (thinking) is stronger in composite, knowledge, long context, multimodal, reasoning.
- GLM 5.3 (max) is stronger in agents & tools, coding, human preference, maths.
- GLM 5.3 (max) is 3.7× cheaper ($2.15 vs $8.00 per 1M blended).
| Metric | Claude Opus 5.5 (thinking) | GLM 5.3 (max) |
|---|---|---|
| BenchLeader Index | 70.7 | 65.4 |
| Composite score | 95.0 | 83.8 |
| Knowledge score | 85.0 | 59.4 |
| Long context score | 68.5 | 66.0 |
| Multimodal score | 71.9 | – |
| Reasoning score | 95.0 | 70.9 |
| Agents & tools score | – | 62.0 |
| Coding score | – | 63.7 |
| Human preference score | – | 68.6 |
| Maths score | – | 62.7 |
| Blended price $/M | $8.00 | $2.15 |
| Output speed | 48 tok/s | 57 tok/s |
| Time to first answer | 4.2 s | 38.3 s |
| Context window | 1M | 1M |
| GPQA Diamond | – | 90.9% |
| FrontierMath Tiers 1–3 | – | 68.8% |
| FrontierMath Tier 4 | – | 29.3% |
| OTIS Mock AIME | – | 91.1% |
| SimpleQA Verified | – | 41.0% |
| Terminal-Bench | – | 41.8% |
| SciCode | – | 59.0% |
| WeirdML | – | 75.4% |
| FrontierCode | – | 40.1% |
| ProofBench | – | 49.0% |
| LMArena Text | – | 1483 |
| LMArena Hard Prompts | – | 1507 |
| LMArena Coding | – | 1524 |
| LMArena WebDev | – | 1614 |
| LMArena Agent | – | 3.1 |
| AA Intelligence Index | 57.6 | 44.8 |
| AA-LCR | 84.7% | 79.7% |
| MMMU-Pro | 87.7% | – |
| AA-Omniscience | 46.4 | 14.3 |
| GPQA Diamond (AA) | – | 91.7% |
| Humanity's Last Exam (AA) | 61.4% | 42.3% |
| SciCode (AA) | 66.9% | 59.0% |
| LiveCodeBench | – | 80.5% |
| MMLU-Pro | – | 86.8% |
| IOI | – | 68.4% |
| LegalBench | – | 84.8% |
| TaxEval | – | 72.4% |
| Terminal-Bench 2.1 (Vals) | – | 71.5% |
| SWE-bench (Vals) | – | 95.4% |
| GPQA Diamond (Vals) | – | 88.1% |
| Vals Index | – | 57.0 |
| CritPt | 31.7% | 19.1% |
| GDPval (AA) | 67.3% | 57.3% |
| τ²-Bench Banking (AA) | – | 50.3% |
| Code Migration | – | 44.2% |
| Excel Modeling Benchmark | – | 56.3% |
| Finance Agent v2 | – | 55.8% |
| Harvey's Legal Agent Benchmark | – | 8.3% |
| Legal Research Bench | – | 49.0% |
| MedCode | – | 42.9% |
| MedScribe | – | 88.8% |
| MysteryMechanism | – | 23.0% |
| ProgramBench | – | 1.5% |
| Public Benefits Bench | – | 68.5% |
| SkillsBench | – | 47.5% |
| Tax Agent Bench | – | 73.1% |
| Terminal-Bench 4.0 (Vals) | – | 25.3% |
| Terminal-Bench Science | – | 4.3% |
| Vibe Code Bench 1-100 | – | 20.0% |
| Vibe Code Bench v1.1 | – | 78.1% |
| FORTRESS | – | 28.2% |
| LMArena Maths | – | 1504 |
| LMArena Creative Writing | – | 1462 |
| LMArena Instruction Following | – | 1480 |
| LMArena Multi-turn | – | 1493 |
| LMArena Longer Queries | – | 1492 |
| Chess Puzzles | – | 21.0% |
| Mystery Game Puzzles | – | 33.0% |
| DeepSWE | – | 69.0% |
| FrontierSWE | – | 30.2% |
| Terminal-Bench 4.0 (AA) | 59.6% | 41.9% |
| Terminal-Bench 2.1 (AA) | – | 83.9% |
| AutomationBench | 69.5% | 62.2% |
| GDP.pdf | 26.2% | 11.2% |
| MLCR | – | 48.3% |
| Harvey LAB | 91.2% | – |
| EnterpriseOps-Gym | – | 36.4% |
| AA-Omniscience: accuracy | 66.2% | 33.9% |
| AA-Omniscience: non-hallucination | 41.4% | 70.5% |
| AA-Briefcase | 1822 | 1525 |
| AA Openness Index | – | 33.3 |
Data as of 2026-09-22. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 5.5 vs GLM 5.3: questions
- Is Claude Opus 5.5 better than GLM 5.3?
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 65.4. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5.5 (thinking) is ahead overall as of 2026-09-22, but check the category scores for your use.
- Which is cheaper, Claude Opus 5.5 or GLM 5.3?
- GLM 5.3 is cheaper: $2.15 against $8.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 5.5 or GLM 5.3?
- GLM 5.3 streams faster: 57 against 48 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.