Promptly

Inspiration

We noticed that many students and professionals use AI tools daily but often struggle to write clear, powerful prompts. Since good prompts make all the difference, we wanted to create something that helps people learn prompt engineering in a fun, engaging way—while also improving their productivity.

What it does

Promptly is a Chrome extension that sits right inside ChatGPT. It gives you instant feedback on your prompts with a score, tips, and suggestions for improvement.

How we built it

We built a Chrome extension that injects UI elements directly into the ChatGPT interface. The backend calls the OpenAI API to analyse and rate prompts, using lightweight logic inspired by prompt engineering best practices. The frontend is kept simple and fast, so it feels natural to use.

Challenges we ran into

Injecting custom buttons into ChatGPT’s interface without breaking things.

Staying within our $10 budget while still demoing reliably with OpenAI.

Designing scoring criteria that feel meaningful, not random.

Making the experience fun instead of “just another productivity tool.”

Accomplishments that we're proud of

We got a fully working Chrome extension prototype in just a weekend.

Built a smooth UX where prompt scoring happens in one click.

What we learned

How to inject custom UI into existing websites with Chrome extensions.

Practical constraints of using AI APIs (tokens, budget, rate limits).

The importance of balancing utility with delight—people like tools that are fun.

Prompt engineering principles matter, but teaching them well takes creativity.

What's next for Promptly

Expand scoring to cover different “prompt styles” (creative writing, coding, tutoring).

Add multiplayer leaderboards so friends can compare prompt mastery.

Support exporting improved prompts to Notion/Obsidian for note-taking workflows.

Build an offline “rule-based” scoring mode for free unlimited use.

Built With

• cursor
• javascript
• openai