DeepSeek V4 Flash vs Grok 4.20

Pick Grok 4.20 if you want the stronger benchmark profile. DeepSeek V4 Flash only becomes the better choice if agentic is the priority or you want the cheaper token bill.

Grok 4.20 is clearly ahead on the provisional aggregate, 76 to 59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Grok 4.20's sharpest advantage is in coding, where it averages 61 against 57.1. The single biggest benchmark swing on the page is SWE-bench Verified, 73.7% to 76.7%. DeepSeek V4 Flash does hit back in agentic, so the answer changes if that is the part of the workload you care about most.

Grok 4.20 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash. That is roughly 21.4x on output cost alone. Grok 4.20 is the reasoning model in the pair, while DeepSeek V4 Flash 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. Grok 4.20 gives you the larger context window at 2M, compared with 1M for DeepSeek V4 Flash.