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Medium complexityWon Singapore GPT-4 Competition

CO-STAR Framework

Context · Objective · Style · Tone · Audience · Response

The Singapore GPT-4 competition winner. Maximum control over voice, audience, and output format.

Definition
The CO-STAR framework (Context · Objective · Style · Tone · Audience · Response) is a prompt engineering structure that breaks your AI request into 6 discrete fields. It is best suited for business communication and marketing copy.

The 6 Fields

1

Context

Background information the AI needs to understand the task and situation.

2

Objective

The specific goal or outcome you want the AI to achieve.

3

Style

The writing style — e.g., formal, conversational, journalistic, academic.

4

Tone

The emotional register — e.g., persuasive, empathetic, authoritative, friendly.

5

Audience

Who the output is for. Shapes vocabulary, depth, and assumptions.

6

Response

The exact output format — e.g., bullet list, 500-word article, JSON, table.

Real Example

Scenario: Writing a product launch email for a SaaS tool targeting CTOs

CO-STAR Prompt

Context: PromptQuorum is a multi-model AI tool launching in April 2026. Objective: Write a product launch email that drives signups. Style: Clear and direct, no fluff. Tone: Confident and professional. Audience: CTOs at mid-size tech companies. Response: 200-word email with subject line.

When to Use CO-STAR

Best for
  • Business communication and marketing copy
  • Content where voice and tone matter (brand writing)
  • Professional writing for a specific audience
  • Any task where you need to control style separately from tone
Not ideal for
  • Quick one-off queries where structure adds no value
  • Sequential multi-step tasks (use RISEN instead)
  • Technical tasks where examples matter more (use TRACE)

Frequently Asked Questions

What does CO-STAR stand for?

CO-STAR stands for Context, Objective, Style, Tone, Audience, and Response — six fields that give you precise control over AI output.

Why did CO-STAR win the Singapore GPT-4 competition?

CO-STAR won because it separates Style (presentation) from Tone (emotion), giving more precise control than frameworks that treat them as one field.

When should I use CO-STAR vs CRAFT?

Use CO-STAR when you need fine-grained control over voice and audience. Use CRAFT when you want a Role-based framing with a clear Target persona.

Related Frameworks

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CO-STAR Prompt Framework — Fields, Examples & When To Use It | PromptQuorum