A deployment that stopped
A crashed process, a redeploy that failed, a plan limit reached: the app is down and the only sign is in a tab you closed.
Monitoring for Replit apps
Your Replit app is live. Who tells you when it isn't?
Replit Agent builds it and Replit runs it. Deployments sleep, secrets get edited, domains lapse, and the editor looks the same whether the app is up or not.
Where it runs: Replit hosts the app on *.replit.app or a custom domain, with its own database and secrets.
Paste your app's address. We propose the checks, you say yes:
We read the page once and propose the checks it needs. Nothing is created until you say so.
Or just check it once, no account:
What breaks after launch
None of these show up in the editor. All of them show up to your users first.
The custom domain
The *.replit.app address is Replit's; the domain you attached is yours to renew, and its DNS must keep pointing where Replit expects.
Secrets and keys
Every outside service the agent connected has a key in Secrets. Rotate one in the provider's dashboard and the feature that used it fails without a message on the page.
The database
The built-in Postgres or the outside one: a paused database returns errors the page may not show.
Scheduled deployments
A scheduled job that fails does so where nobody is looking.
The email problem
Replit apps send mail through a provider the agent set up (Resend, SendGrid, Gmail via SMTP) with a key in Secrets and, if you set it up, a domain of your own with SPF and DKIM. The sending path breaks on the provider side (key, quota, billing) and the DNS side (records edited, domain lapsed) and the app cannot tell: the call was made, the response was accepted, the mail never arrived. ServerInspector checks the deployed app and its domain from outside on a schedule; on Pro, an API test calls the route that sends and tells you when the answer changes.
How to set it up
Nothing is installed in the app. Monitoring happens from outside, the way your users reach it.
- 1
Type your app's address into the free check above. It tells you in twenty seconds whether the site answers, how fast, whether the certificate and domain are in order, and which security headers are missing.
- 2
Create a free account and add the same address as a monitor. It is checked every five minutes (every minute on Pro), and you get an email when it stops answering and another when it is back.
- 3
Add your custom domain under Domains. Expiry is tracked and you are reminded 30, 14, 7 and 1 day before renewal.
- 4
If your app has an API, add its health route as a monitor with an expected status. A sleeping or crashed deployment answers differently.
- 5
On Pro, an API test for the sending route with a test flag, every fifteen minutes.
Free plan: 10 monitors or domains, 5-minute checks, commercial use welcome, no card.