Is GPT-5.3 Chat or DeepSeek V4 Flash cheaper?

DeepSeek V4 Flash is cheaper on output tokens ($0.28 vs $14.00 per 1M).

Which has the larger context window, GPT-5.3 Chat or DeepSeek V4 Flash?

DeepSeek V4 Flash has the larger context window (1M tokens).

GPT-5.3 Chat vs DeepSeek V4 Flash

DeepSeek V4 Flash is cheaper on output tokens, while DeepSeek V4 Flash offers a larger context window. Choose GPT-5.3 Chat or DeepSeek V4 Flash based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT-5.3 Chat	DeepSeek V4 Flash
Provider	ZenMux	ZenMux
Input / 1M tokens	$1.75	$0.14
Output / 1M tokens	$14.00	$0.28
Context window	128K	1M
Parameters	—	284B
Open weights	No	Yes
Released	Mar 2026	Apr 2026

GPT-5.3 Chat details →DeepSeek V4 Flash details →

FAQ

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