Take your Replit app from prototype to production
Practical guides to shipping Replit Agent apps: what breaks after you publish, and how to fix it step by step, with a copy-paste prompt for Agent in every fix.
Getting started
Is Replit production-ready? An honest answer for business apps
Can you run a real business app on Replit? What the platform handles well, where AI-built apps fall short, and a 10-point test before you launch.
Read the guide →ComparisonReplit vs Lovable vs Bolt for business apps: which should you choose?
An independent comparison of Replit, Lovable and Bolt for real business apps: backend, database, deployment, background jobs and code ownership.
Read the guide →Security
Replit Agent security checklist: 15 checks before you launch
15 security checks for Replit Agent apps before launch: secrets, authorization, validation, data, dependencies and costs, with how to test and fix each.
Read the guide →Security · SupabaseSupabase's October 30 grants change: what breaks, and the prompt that fixes it
From Oct 30, 2026, new Supabase tables in public need an explicit GRANT or the Data API returns 42501. The fix, a Lovable/Bolt prompt and a self-check.
Read the guide →SecurityReplit Secrets: how to store API keys safely
How Replit Secrets work, how to read them in Node.js and Python, how to keep keys out of the browser and Agent chats, and what to do after a leak.
Read the guide →Deployment
How to deploy a Replit app to production, step by step
A launch runbook for Replit apps: pick the deployment type, set production secrets, prepare the database, connect a custom domain and add monitoring.
Read the guide →DeploymentReplit Autoscale vs Reserved VM vs Static vs Scheduled: which deployment should you choose?
Autoscale, Reserved VM, Static or Scheduled? How each Replit deployment type works, cold starts, background jobs and costs, plus a 30-second decision tree.
Read the guide →DeploymentReplit deployment failed: fix the port and 0.0.0.0 errors
Publishing fails at the promote step, or the live app says it failed to respond? Fix the host, PORT and .replit port settings that break Replit deployments.
Read the guide →DeploymentReplit app works in preview but not after deploy
Your Replit Agent app works in the preview but breaks once published: missing data, failed API calls, login or payments. The checklist that finds the cause.
Read the guide →DeploymentReplit secrets not working in deployment? How to fix it
Your API key works in the workspace but is undefined in the published Replit app. Check deployment secrets, sync, republishing and frontend build variables.
Read the guide →DeploymentReplit custom domain or SSL not working? Fix the DNS
Custom domain stuck on Verifying, SSL errors, or "deployment could not be reached" on Replit? Fix the A and TXT records, Cloudflare proxy, AAAA and CAA issues.
Read the guide →DeploymentReplit app shows 404 on page refresh? Fix SPA routing
Your React app on Replit works from the homepage, but deep links and refresh return 404. Add the right fallback route or rewrite without breaking APIs.
Read the guide →DeploymentReplit deployment build failed: how to read the logs and fix it
Replit publish fails during the build, gets stuck, or says the image exceeds 8 GiB? Read the build log, find the first error and fix the usual causes.
Read the guide →DeploymentReplit Autoscale cold starts: why the first load is slow
Your Replit app takes seconds to load after a quiet period? That is an Autoscale cold start. Shorten startup, or choose Reserved VM when it really matters.
Read the guide →DeploymentReplit cron jobs not running in production? Here is why
Your setInterval or node-cron job works in the preview but not on Replit Autoscale. Move it to a Scheduled deployment or a protected endpoint on a schedule.
Read the guide →DeploymentReplit changes not showing after deploy? 5 reasons and fixes
You published, but the live Replit app still shows the old version. Republish, fix index.html caching and service workers, and check the data source.
Read the guide →Data
Replit development vs production database: how it works, and how not to lose data
How Replit's dev and production databases work, what Agent can't touch, how schema changes reach production, and 5 habits to never lose customer data.
Read the guide →DataReplit database connection errors in production: how to fix them
DATABASE_URL not set, endpoint disabled, SSL required or pool exhausted in your published Replit app? Diagnose the error and fix the Postgres connection.
Read the guide →DataUploaded files disappear after you redeploy on Replit? Fix it
User uploads, avatars or generated PDFs vanish after a Replit republish or restart. The published filesystem is not persistent: move files to App Storage.
Read the guide →DataHow to run database migrations on Replit production safely
Schema changes work in dev but break the published Replit app, or publishing warns about data loss. Apply migrations to production without dropping data.
Read the guide →Costs
Replit Agent costs: 12 ways to cut your bill without slowing down
Why Replit Agent bills climb under effort-based pricing, where the money goes (Agent, deployments, databases) and 12 habits to keep spend predictable.
Read the guide →CostsReplit deployment costs too high? How to find and cut them
Your Replit hosting bill is higher than expected. Find what drives it, then fix timers, keep-alive pingers, machine size, max machines and heavy files.
Read the guide →Troubleshooting
Replit Agent keeps breaking your app? How to stop the fix loop
Why Replit Agent fixes one bug and breaks another, how to roll back safely with checkpoints, and a prompting workflow that stops the loop.
Read the guide →PaymentsStripe webhook not working on Replit? How to fix it
Payments succeed but your Replit app never updates? Fix the webhook URL, signing secret, raw body, test vs live mode and middleware that block Stripe.
Read the guide →AuthGoogle sign-in fails on Replit with redirect_uri_mismatch: fix it
Google login works in the preview but fails on your published Replit app with Error 400 redirect_uri_mismatch. Register the right URLs and fix the callback.
Read the guide →AuthLogin not working after deploy on Replit? Fix sessions and cookies
Users log in on your Replit app, then get logged out on the next click or loop back to login. Fix trust proxy, secure cookies, session secret and store.
Read the guide →TroubleshootingCORS error on your Replit deployment? How to fix it
Blocked by CORS policy after publishing on Replit? Use relative API URLs, allow only your real origins, handle credentials, and spot crashes posing as CORS.
Read the guide →TroubleshootingReplit 502 Bad Gateway or 500 error after publishing: how to fix it
Your published Replit app returns 502 Bad Gateway, a 500 error or Application failed to respond. Find the crash in the logs, fix it, or roll back fast.
Read the guide →TroubleshootingVite environment variables undefined on Replit? Here is why
import.meta.env values are undefined in your Replit React app, or process is not defined in the browser. Fix the VITE_ prefix and build-time values safely.
Read the guide →SEOReplit app not indexed by Google? How to fix it
Google ignores your Replit app, robots.txt or sitemap.xml returns HTML, or every page has the same title. Fix the technical SEO basics of a Replit Agent app.
Read the guide →Replit AgentHow to roll back Replit Agent changes (and what happens to your data)
Agent broke your app? How Replit checkpoints and rollbacks work, why the database is not restored by default, and how to update the live app afterwards.
Read the guide →