Comparing 2 models
Claude Opus 5.5 vs GLM 5.3 Flash
Benchmarks through
Verdict
Claude Opus 5.5 places higher on 9 of the 11 tasks where both are ranked. GLM 5.3 Flash costs 164.6x less per input token. GLM 5.3 Flash accepts 1.0x more context. Only GLM 5.3 Flash has open weights for self-hosting.
- Choose Claude Opus 5.5 for OpenClaw (#1), Goose (#1), OpenHands (#1).
- Choose GLM 5.3 Flash for JSON & Schema Output (#3), Structured Data Extraction (#3), you need to self-host.
Built from the published task rankings below; ranks come from each task's own weighted benchmarks, so a win on one task says nothing about another.
Measured head to head
Benchmarks both models were run on
| Evaluation | Claude Opus 5.5 | GLM 5.3 Flash | Source |
|---|---|---|---|
| Design Arena Coding | 1392 Elo | 1285 Elo | source · 2026-10-16 |
| Design Arena UI | 1378 Elo | 1318 Elo | source · 2026-10-16 |
| Design Arena Website | 1338 Elo | 1274 Elo | source · 2026-10-16 |
| FrontierMath Tiers 1-3 (Epoch AI) | 91.2% ± 1.7 | 55.8% ± 2.9 | source · 2026-09-22 |
| GPQA Diamond (Epoch AI) | 90.6% ± 1.9 | 90.2% ± 1.7 | source · 2026-09-22 |
| LiveBench Agentic Coding | 71.7% | 56.8% | source · 2026-10-16 |
| LiveBench Coding | 89.3% | 79.0% | source · 2026-10-16 |
| LiveBench Data Analysis | 80.3% | 76.4% | source · 2026-10-16 |
| LiveBench Instruction Following | 65.7% | 52.8% | source · 2026-10-16 |
| LiveBench Language | 86.3% | 77.3% | source · 2026-10-16 |
| LiveBench Math | 97.1% | 81.2% | source · 2026-10-16 |
| LiveBench Reasoning | 92.2% | 77.6% | source · 2026-10-16 |
| LMArena Agent | 17.2 | -1.1 | source · 2026-10-14 |
| LMArena Agent Bash Recovery | 13.6 | -5.7 | source · 2026-10-08 |
| LMArena Agent Steerability | 17.9 | -3 | source · 2026-10-14 |
| LMArena Agent Task Outcome | 19.4 | 3.9 | source · 2026-10-14 |
| LMArena Agent Tool Hallucination | 0.5 | 0.6 | source · 2026-10-14 |
| LMArena Creative Writing | 1534 Elo | 1441 Elo | source · 2026-10-15 |
| LMArena Instruction Following | 1536 Elo | 1478 Elo | source · 2026-10-15 |
| LMArena Long Query | 1531 Elo | 1482 Elo | source · 2026-10-15 |
| LMArena Math | 1508 Elo | 1505 Elo | source · 2026-10-15 |
| LMArena Text | 1508 Elo | 1474 Elo | source · 2026-10-15 |
| LMArena Text Factuality | 1509 Elo | 1463 Elo | source · 2026-10-15 |
| LMArena Vision | 1293 Elo | 1273 Elo | source · 2026-10-09 |
| LMArena Vision Diagrams | 1324 Elo | 1306 Elo | source · 2026-10-09 |
| LMArena Vision OCR | 1307 Elo | 1284 Elo | source · 2026-10-09 |
| LMArena WebDev | 1811 Elo | 1606 Elo | source · 2026-10-13 |
| LMArena WebDev Image-to-Web | 1749 Elo | 1581 Elo | source · 2026-10-09 |
| OTIS Mock AIME (Epoch AI) | 100% ± 0 | 93.9% ± 2.2 | source · 2026-09-22 |
| Terminal-Bench (4.0) | 64.8% | 35.8% | source · 2026-10-16 |
Values are as published by each evaluator, in its own units; rows from different evaluators are not on a common scale.
task evidence
How they place when the question changes
Lower ranks are better. “Best” marks the strongest option in this shortlist for that task.