When Thunkable's live preview won't connect to your iPhone or stops updating, the cause is usually network, account, or app-version related. Here's a focused fix guide.
Thunkable's live preview lets you see your project running on a real iPhone as you edit, and when it breaks it stalls your whole workflow.
The frustration is that the fix is rarely in your app — it's almost always the connection between the web editor and the companion app.
The live preview relies on your computer and your phone communicating, and on both being signed into the same project and account.
When any link in that chain breaks, you get a preview that won't load, won't connect, or won't reflect your latest changes.
This guide works through the causes in the order most likely to solve your problem, so you can get back to building quickly.
The single most common cause of live-preview failure is a network mismatch.
Your computer and iPhone should be on the same Wi-Fi network. A laptop on Wi-Fi and a phone on cellular data is a classic silent failure.
Turn off cellular data on your phone temporarily, or explicitly connect both devices to the same network, and try again.
Restrictive networks are the next culprit. Corporate, school, and public Wi-Fi frequently block the communication live preview needs.
If you suspect this, switch to a personal hotspot or a home network. This resolves a large share of connection problems instantly and is worth trying early.
If the network is fine, check that both ends are looking at the same thing.
Confirm you're signed into the companion app on your iPhone with the same account you're using in the web editor. A different account won't show your project.
Make sure you actually opened the project you intend to preview, and that you're scanning the current QR code or selecting the right project in the app.
If you recently switched accounts or projects, sign out and back in on the companion app to refresh its state.
These mismatches are easy to overlook and quick to fix, so rule them out before assuming something is broken.
An outdated companion app is a frequent, non-obvious cause of trouble.
The Thunkable editor evolves, and an old version of the live app may fail against newer features or simply behave unpredictably.
Open the App Store and update the Thunkable companion app to the latest version.
If it's already current but misbehaving, force-quit and reopen it. If problems persist, delete and reinstall the app to clear a corrupted state.
After reinstalling, sign back in and grant the permissions your project needs.
Keeping the companion app current eliminates a whole category of mysterious preview failures.
A different symptom: the app loads, but your latest edits don't appear.
First, confirm the edit actually saved in the editor. Refresh the web editor to be sure it's showing your current work.
Sometimes the live connection drifts. Disconnect and reconnect — re-scan the QR code or reopen the project in the companion app to re-establish a fresh link.
A weak or congested network can also delay updates. Move closer to your router or switch networks if changes are lagging badly.
If a specific new component won't render, force-quit and relaunch the companion app so it reloads the project cleanly.
Re-establishing the connection resolves most "it won't update" cases.
Sometimes preview connects and updates, but one feature just won't behave.
Start with permissions. If it's a camera, location, microphone, or notification feature, check iOS Settings for the companion app and confirm the needed permission is granted.
Next, remember what live preview structurally can't do. Some capabilities — push notifications, in-app purchases, certain background tasks, and final performance — only work fully in a real installed build, not the preview host.
So a feature failing in live preview isn't always a bug; it may simply be outside what preview can demonstrate.
For those, build a real test version and install it to verify.
Separating "preview limitation" from "actual bug" saves you from chasing problems that aren't really there.
If nothing above worked, do a clean, systematic reset.
Close the companion app fully and close or refresh the web editor. Reconnect both devices to a known-good network, ideally a personal hotspot to rule out restrictions.
Update or reinstall the companion app, sign in with the correct account, and reopen the intended project.
Reconnect via a fresh QR scan.
Try a brand-new, minimal test project with a single button. If that connects and the problem project doesn't, the issue is specific to that project rather than your setup.
Isolating the variable this way tells you whether to keep debugging locally or to escalate.
If you've worked through network, account, app version, and a clean reset and preview still fails, it's time to ask for help.
Gather specifics before you do: your iOS version, the companion app version, the network type, exactly what happens, and what you've already tried.
Reach out to Thunkable's support channels or community forum with those details. Precise reports get faster, better answers than "it doesn't work."
Also check Thunkable's status and documentation in case there's a known issue or a recent change to the preview flow.
Most live-preview problems are environmental and solvable in minutes, but when they aren't, a well-documented report is your fastest route to a resolution.
A little discipline keeps most live-preview headaches from happening at all.
Before each session, connect both your computer and iPhone to the same reliable network, ideally one you control rather than restrictive corporate or public Wi-Fi.
Keep the companion app updated so it stays in step with editor changes, and keep your iOS version reasonably current.
Stay signed into the same account on both ends, and get in the habit of confirming which project is open before you scan the QR code.
Finally, remember the mental model: live preview is a fast iteration loop, not a substitute for a final installed build. Push notifications, in-app purchases, and some background behavior only work fully in a real signed build.
Build those habits and you'll spend your time creating instead of reconnecting. When you do finally publish, that same installed-build testing discipline carries straight into a smoother App Store submission.
Usually your computer and phone are on different networks, or a restrictive corporate or public Wi-Fi is blocking the connection. Put both devices on the same network or use a personal hotspot, then reconnect.
Confirm the edit saved and refresh the editor, then disconnect and reconnect the companion app to re-establish the link. A weak network can also delay updates.
Check that the companion app has the needed iOS permission. Also remember that push notifications, in-app purchases, and some background tasks only work in a real installed build, not the live preview.
If updating doesn't help, reinstalling clears a corrupted state and often fixes stubborn connection issues. Sign back in with the correct account and re-grant permissions afterward.