Claude Sonnet 4.5 vs Gemma 4 31B

Treat this as a split decision. Claude Sonnet 4.5 makes more sense if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model; Gemma 4 31B is the better fit if you want the cheaper token bill or you need the larger 256K context window.

Claude Sonnet 4.5 and Gemma 4 31B finish on the same provisional overall score, so this is less about a single winner and more about where the edge shows up. The provisional headline says tie; the benchmark table is where the real choice happens.

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 Gemma 4 31B. That is roughly Infinityx on output cost alone. Gemma 4 31B 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. Gemma 4 31B gives you the larger context window at 256K, compared with 200K for Claude Sonnet 4.5.