Which one
Default todeepseek-v4-flash for new work — it gives you 1M context, native
reasoning, and the same family behaviour at a fraction of the cost. Stay on
deepseek-v3 if you have a production workload already tuned to it.
deepseek-r1 is the reasoning specialist: slower, and worth it for maths and
step-by-step analysis where you want the chain of thought exposed.