Is Step 3.5 Flash 2603 or Phi-4 cheaper?

Step 3.5 Flash 2603 is cheaper on output tokens ($0.30 vs $0.50 per 1M).

Which has the larger context window, Step 3.5 Flash 2603 or Phi-4?

Step 3.5 Flash 2603 has the larger context window (256K tokens).

Step 3.5 Flash 2603 vs Phi-4

Step 3.5 Flash 2603 is cheaper on output tokens, while Step 3.5 Flash 2603 offers a larger context window. Choose Step 3.5 Flash 2603 or Phi-4 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	Step 3.5 Flash 2603	Phi-4
Provider	StepFun AI	Azure
Input / 1M tokens	$0.10	$0.13
Output / 1M tokens	$0.30	$0.50
Context window	256K	128K
Parameters	—	—
Open weights	Yes	Yes
Released	Apr 2026	Dec 2024

Step 3.5 Flash 2603 details →Phi-4 details →

FAQ

Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.