OpenAI: GPT-3.5 Turbo Instruct

GPT-3.5 Turbo Instruct is a text-in, text-out completion model from OpenAI with a 4,095-token context window. It does not support tool use, reasoning modes, or structured output, and accepts no image or audio input. The instruct variant is oriented toward direct completion tasks rather than back-and-forth conversation, making it a narrow-purpose option compared to chat-tuned alternatives. At $1.50 per million input tokens and $2.00 per million output tokens, it sits in the budget tier, which may appeal to developers running high-volume, straightforward text-generation workloads where short context is sufficient. The tradeoff is that no independent benchmark coverage exists for this model, so quality claims are currently unverifiable against external standards. Teams that need proven performance data before committing, or that require tools, structured output, or longer context, should look elsewhere until coverage improves.