Claude Sonnet 5.5 vs GLM 5.3 Flash
Claude Sonnet 5.5 
GLM 5.3 Flash Verdict
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 62.2.
- Claude Sonnet 5.5 (max) is stronger in agents & tools, coding, composite, knowledge, long context, maths, reasoning.
- GLM 5.3 Flash is stronger in human preference, multimodal.
- GLM 5.3 Flash is 17× cheaper ($0.238 vs $4.00 per 1M blended).
- Claude Sonnet 5.5 (max) streams 2.7× faster (141 vs 53 tokens per second).
| Metric | Claude Sonnet 5.5 (max) | GLM 5.3 Flash |
|---|---|---|
| BenchLeader Index | 67.6 | 62.2 |
| Agents & tools score | 69.5 | 62.7 |
| Coding score | 69.8 | 63.4 |
| Composite score | 72.6 | 58.6 |
| Knowledge score | 65.4 | 65.0 |
| Long context score | 66.6 | 65.2 |
| Maths score | 72.9 | 69.0 |
| Reasoning score | 81.1 | 67.0 |
| Human preference score | – | 67.0 |
| Multimodal score | – | 64.2 |
| Blended price $/M | $4.00 | $0.238 |
| Output speed | 141 tok/s | 53 tok/s |
| Time to first answer | 487.1 s | 41.0 s |
| Context window | 1M | 1M |
| GPQA Diamond | 95.6% | – |
| FrontierMath Tiers 1–3 | 88.8% | – |
| FrontierMath Tier 4 | 80.5% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 46.5% | – |
| Terminal-Bench | 61.8% | – |
| SciCode | 61.0% | 51.6% |
| APEX-Agents | 75.5% | 52.8% |
| ProofBench | 100.0% | – |
| Epoch Capabilities Index | – | 151.9 |
| LMArena Text | – | 1475 |
| LMArena Hard Prompts | – | 1501 |
| LMArena Coding | – | 1525 |
| LMArena WebDev | – | 1609 |
| LMArena Vision | – | 1296 |
| LMArena Agent | 12 | -1 |
| LiveBench | 75.7% | 71.6% |
| LiveBench Reasoning | 91.6% | 77.6% |
| LiveBench Coding | 91.4% | 79.0% |
| LiveBench Agentic Coding | 56.3% | 56.8% |
| LiveBench Mathematics | 96.1% | 81.2% |
| LiveBench Data Analysis | 59.5% | 76.4% |
| LiveBench Language | 78.0% | 77.3% |
| LiveBench Instruction Following | 56.8% | 52.8% |
| AA Intelligence Index v4.3.2 | 56 | 41.8 |
| AA-LCR | 82.7% | 80.0% |
| AA-Omniscience | 32.3 | 7.5 |
| GPQA Diamond (AA) | – | 91.2% |
| Humanity's Last Exam (AA) | 55.0% | 39.9% |
| SciCode (AA) | 61.0% | 51.6% |
| CritPt | 31.4% | 15.4% |
| GDPval-AA v2.1 | 67.0% | 57.2% |
| τ³-Banking (AA) | – | 47.2% |
| ITBench SRE (AA) | – | 51.2% |
| Analyst Agent (AA) | 57.5% | – |
| LMArena Maths | – | 1502 |
| LMArena Creative Writing | – | 1435 |
| LMArena Instruction Following | – | 1472 |
| LMArena Multi-turn | – | 1472 |
| LMArena Longer Queries | – | 1481 |
| Mystery Game Puzzles | 65.0% | – |
| CursorBench | 55.5% | – |
| FrontierSWE | 61.9% | – |
| BTF-3 | – | 14.9% |
| Terminal-Bench 4.0 (AA) | 63.6% | 32.8% |
| Terminal-Bench 2.1 (AA) | – | 84.3% |
| AutomationBench | 71.8% | 60.4% |
| GDP.pdf | 25.8% | 15.4% |
| MLCR | 75.0% | 51.1% |
| Harvey LAB | 2.8% | 0.8% |
| EnterpriseOps-Gym | – | 33.2% |
| AA-Omniscience: accuracy | 54.0% | 27.5% |
| AA-Omniscience: non-hallucination | 53.0% | 72.4% |
| AA-Briefcase v1.1 | 1823 | 1454 |
| AA Openness Index | – | 44.4 |
Data as of 2026-10-11. Best configuration of each model; every score links to its source on the model pages.
Claude Sonnet 5.5 vs GLM 5.3 Flash: questions
- Is Claude Sonnet 5.5 better than GLM 5.3 Flash?
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 62.2. The BenchLeader Index combines every independent quality benchmark; Claude Sonnet 5.5 (max) is ahead overall as of 2026-10-11, but check the category scores for your use.
- Is Claude Sonnet 5.5 better than GLM 5.3 Flash for coding?
- Claude Sonnet 5.5 scores higher in coding (70 vs 63 on the category index, where 50 is average).
- Is Claude Sonnet 5.5 better than GLM 5.3 Flash for agentic tasks?
- Claude Sonnet 5.5 scores higher in agentic tasks (70 vs 63 on the category index, where 50 is average).
- Which is cheaper, Claude Sonnet 5.5 or GLM 5.3 Flash?
- GLM 5.3 Flash is cheaper: $0.238 against $4.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Sonnet 5.5 or GLM 5.3 Flash?
- Claude Sonnet 5.5 streams faster: 141 against 53 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.