Is Step 3.5 Flash or GPT-5.1 cheaper?

Step 3.5 Flash is cheaper on output tokens ($0.30 vs $9.00 per 1M).

Which has the larger context window, Step 3.5 Flash or GPT-5.1?

GPT-5.1 has the larger context window (400K tokens).

Step 3.5 Flash vs GPT-5.1

Step 3.5 Flash is cheaper on output tokens, while GPT-5.1 offers a larger context window. Choose Step 3.5 Flash or GPT-5.1 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	Step 3.5 Flash	GPT-5.1
Provider	StepFun AI	Poe
Input / 1M tokens	$0.10	$1.10
Output / 1M tokens	$0.30	$9.00
Context window	256K	400K
Parameters	—	—
Open weights	Yes	No
Released	Jan 2026	Nov 2025

Step 3.5 Flash details →GPT-5.1 details →

FAQ

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