GPT-3.5 Turbo Instruct
GPT-3.5 Turbo Instruct is a specialized variant of GPT-3.5 that exposes the legacy completion (non-chat) API endpoint, optimized for prompt-response instruction tasks rather than multi-turn dialogue. Unlike the chat-based 3.5 Turbo models, this variant accepts a plain text prompt and returns a completion, making it compatible with software built against the older completions API.
It is useful for classic NLP tasks — text transformation, rewriting, extraction, and classification — where a single-turn instruction format fits naturally and the application architecture expects a completion-style interface. It also suits fine-tuning workflows and legacy integrations that have not migrated to the chat endpoint.
Key Features
Completions API compatibility for legacy non-chat integrations
Optimized for single-turn instruction-following and prompt-response tasks
Text transformation: rewriting, summarizing, classifying, extracting
Supports fine-tuning via the OpenAI fine-tuning API
Low-latency responses suitable for real-time applications
Familiar behavior for teams migrating from earlier GPT-3 or Davinci models
Ideal Use Cases
Powering legacy applications built on the OpenAI completions API
Text transformation pipelines: paraphrasing, style transfer, extraction
Fine-tuning a custom instruction-following model for domain-specific tasks
Single-turn question answering or command-execution interfaces
Example Prompts for GPT-3.5 Turbo Instruct
Technical Specifications
| Provider | OpenAI |
| Category | Text |
| Modality | Text -> Text |
| Context Window | 4,096 tokens |
| Training Cutoff | September 2021 |
Frequently Asked Questions
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