Claude Sonnet 4.5 vs Qwen3.5-122B-A10B

Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. Qwen3.5-122B-A10B only becomes the better choice if reasoning is the priority or you want the cheaper token bill.

Claude Sonnet 4.5 finishes one point ahead on BenchLM's provisional leaderboard, 66 to 65. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

Claude Sonnet 4.5's sharpest advantage is in coding, where it averages 77.2 against 72. The single biggest benchmark swing on the page is SWE-bench Verified, 77.2% to 72%. Qwen3.5-122B-A10B does hit back in reasoning, so the answer changes if that is the part of the workload you care about most.

Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Qwen3.5-122B-A10B. That is roughly Infinityx on output cost alone. Qwen3.5-122B-A10B is the reasoning model in the pair, while Claude Sonnet 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. Qwen3.5-122B-A10B gives you the larger context window at 262K, compared with 200K for Claude Sonnet 4.5.