Claude Opus 4.5 vs Qwen3.5-27B

Pick Claude Opus 4.5 if you want the stronger benchmark profile. Qwen3.5-27B only becomes the better choice if instruction following is the priority or you want the cheaper token bill.

Claude Opus 4.5 is clearly ahead on the provisional aggregate, 77 to 63. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.5's sharpest advantage is in agentic, where it averages 62.5 against 51.6. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 59.3% to 41.6%. Qwen3.5-27B does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Qwen3.5-27B. That is roughly Infinityx on output cost alone. Qwen3.5-27B is the reasoning model in the pair, while Claude Opus 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Qwen3.5-27B gives you the larger context window at 262K, compared with 200K for Claude Opus 4.5.