Try it before you share it

Before you share your app with the world, you'll test it the way a real user would, and let the agent and the platform run their own checks too.

1. Walk through your app like a visitor

Open the live preview (see Previewing & iterating if you need a refresher) and test like a visitor would:

Click every button - navigation links, submit buttons, "Learn More" cards - to make sure they all do something.
Alignment - Check if any alignment issues when you change screen sizes or zoom or open in a new tab or incognito tabs.
Fill out forms - type into fields, pick dropdowns, toggle checkboxes. Hit submit and watch for success messages or errors.
Test full flows- if you have set up OTP or payment flows (or any other process flows), check them end to end: whether OTPs are generated, each time it is different, payments are landing correctly etc.
Navigate between pages - use menus, back buttons, and links to move around. Nothing should break or show a blank screen.
Footers - if required, add links to terms & conditions, legal policies, contact, social media etc at the bottom of the page and verify the links work

2. Quick visual & data checklist

Before you publish or share the link, scan for these common gotchas:

Images load - no broken placeholders or missing icons.

-- Uploads work - if your app asks the user to upload something, verify the uploads work, and do resolution and format checks.

Text is readable - font sizes work on small screens, colors have enough contrast.
Forms validate - try submitting empty fields or wrong formats (like "abc" in an email box). The app should show helpful error messages.
Data appears - if your app fetches data (from its database or a connected service), confirm it shows up. Check the browser console for red error messages if something's missing.

3. Let the agent test it

You can ask the agent to test what it built (but don't skip the manual checks after this):

Test the app end to end and report anything broken

The agent has a built-in testing capability and runs checks toward the end of a build; asking explicitly makes it exercise the flows you care about. For how the agent uses your feedback to debug, see Debugging & testing with the agent.

4. Check it on a real device

Click the view(desktop/mobile/tablet) button in the preview pane, or open the preview URL on your phone. Make sure text doesn't overlap, buttons aren't cut off, and everything still works.
Check the web app works cross-platform: windows vs mac, android vs iOS.
Building a mobile app? Scan the QR code from inside the Expo Go app (not your camera app), see Pre-publish health check for the full walkthrough.

Report what's broken

When you find a bug, describe exactly what you did, what you expected, and what actually happened in the chat. The more detail you give, the faster the agent can fix it.

Good example:

I clicked the "Add to Cart" button on the product detail page.
I expected the item count in the cart icon to go up, but nothing happened.
Screenshot attached.

Not enough detail:

The button doesn't work.

If the issue is visual, attach a screenshot (drag the image into the chat). If you see red text in the browser console (right-click anywhere on the page → Inspect → Console tab), copy the entire error message, right-click the error and select "Copy" to grab the full output including the stack trace, and paste it into the chat. Then tell the agent exactly how to trigger the bug:

Which page were you on?
What did you click or type?
Did it happen the first time, or only after doing something else first?

This context helps the agent fix issues that only show up under certain conditions.

If something still looks wrong after a fix

The agent will rebuild the preview after every change. Give it a few seconds, then test the same flow again to confirm the fix worked. If the bug persists:

Try the steps one more time - be extra specific about what's still broken.
Check if the error message changed (that means the agent is making progress).
If you're stuck after a couple of rounds, When something breaks has the full triage path, including how to tell a config problem from a code problem, and what to send support.

Once everything works smoothly in the preview, you're ready to publish and share it with real users.

Go deeper: Pre-publish health check for web apps