CO-STAR Extension
Structures your ChatGPT prompts using Singapore GovTech's CO-STAR framework instead of freeform text.
At a glance
Starts at
Free
Listed as free on the Chrome Web Store.
Free tier
Yes
Platforms
Chrome
Best for
People wanting a structured framework for ChatGPT prompts
Not for
Anyone comfortable freeform prompting without a fixed structure
5.0 out of 5
Scored by Alex after real useOur verdict
CO-STAR Extension takes the CO-STAR prompt framework built by Singapore's GovTech and turns filled-in fields into a formatted ChatGPT prompt, with a real-time preview before you send it. People who want a repeatable structure rather than guessing at prompt wording each time will get the most out of it. Locking prompts into one fixed framework means it won't suit every kind of request.
✓What it does well
Structured prompt frameworkApplies the CO-STAR framework to structure prompts consistently.
Real-time previewShows a live preview of the formatted prompt before sending.
Chrome integrationIntegrates directly into the Chrome toolbar for quick access.
✕Where it falls short
One fixed frameworkLocks prompts into a single framework, not flexible formats.
ChatGPT focusedIs built only around ChatGPT, not other AI chat tools.
Manual field fillingRequires filling in each CO-STAR field by hand.
Key features
CO-STAR fieldsProvides input fields for each part of the CO-STAR framework.
Auto-formattingFormats entered text into a structured prompt automatically.
Live previewPreviews the finished prompt in real time as you type.
Toolbar accessOpens directly from the Chrome toolbar icon.