I’m having a strange issue with my Node.js application on Replit. The Preview feature seems to be running an old version of my code, but when I manually start the server everything works perfectly.
Here’s what happened: I pushed my latest changes to the main branch and synced everything with Replit. Usually, the Preview tab picks up new code automatically, but this time my web app appears broken in Preview mode. The weird thing is that my code runs fine locally and in other environments.
When I open a terminal in Replit and execute npm run dev manually, the application works exactly as expected. This makes me think there might be some caching or version mismatch between what Preview uses versus the manual server startup.
Does anyone know if there’s a specific way to refresh or restart whatever server process the Preview tab uses? Maybe I need to trigger some kind of rebuild through the Replit interface to get Preview working with my latest code changes?
yeah, i’ve had this bug too - sometimes replit’s preview just gets stuck. try clearing your browser cache, that usually helps. also check the .cache folder for any old files & just delete em. if all else fails, do a hard refresh with ctrl+f5.
It seems you’re encountering a common issue with Replit’s Preview feature. Often, the Preview runs in a separate process that doesn’t always sync with the latest changes you push. A good approach to resolve this is to terminate any running processes; you can execute pkill node in the Shell or restart the project entirely through the three-dot menu. Following this, make a minor adjustment to your main file and save it—this usually prompts Replit to reload the Preview with the latest updates. Additionally, ensure that your .replit file has the correct run command; it should match your npm run dev script. Discrepancies there can lead to the behavior you’re seeing.
stop the repl completely with the stop button, then hit run again. preview sometimes gets stuck on old processes even after you kill nodes. also check for a .replit.nix file - it might be caching dependencies. delete it to force a fresh rebuild.
Had the same issue last month - turned out to be environment variables. Replit Preview loads different env settings than when you start the server manually, especially after updating secrets or config. Check your Secrets tab and compare what variables load with Preview vs manual startup. Add a quick console.log of process.env in your startup code to see the difference. Preview also has weird port binding that messes with hot reload, so if your app uses file watchers or auto-restart, Preview might not catch those changes.
Been there, dealt with this exact headache multiple times. The Preview tab caching issue is super annoying when you’re trying to iterate quickly.
What works better is automating the whole deployment process instead of relying on Replit’s wonky Preview system. You can set up a workflow that automatically deploys your latest code to a proper staging environment every time you push changes.
I use Latenode to create scenarios that watch my git repo, pull the latest changes, run tests, and deploy to a clean environment. Takes like 10 minutes to set up but saves hours of debugging these weird caching issues.
The automation handles everything - from detecting new commits to spinning up fresh instances with your latest code. No more guessing if Preview is showing old stuff or dealing with manual restarts.
Plus you get a real deployment pipeline that works the same way every time, unlike Replit’s Preview which seems to have a mind of its own.
This happens because Replit’s Preview tab runs a separate process that doesn’t always die when you make changes - so you end up running stale code. Here’s what works: go to the Processes tab in your sidebar and kill any running node processes. Then make a tiny edit to your main server file (add a space or comment) and save. This forces Replit to start fresh with your updated code. Also check your package.json scripts - Preview might use the default start command while you’re manually running dev, and if these point to different files or configs, you’ll get different behavior.