Security for apps built on Replit
Replit's agent can build and host a full app from a prompt. That convenience is also how secrets end up exposed and data ends up public. Start with a free external snapshot, then check what lives inside.
Built and hosted in one place, exposed in one place too
Because Replit builds and deploys together, it is easy to ship quickly, and just as easy to ship with a secret committed into the code, a database left open, or default settings that expose more than you intended. The app runs fine either way, which is why these slip through.
The outside view can’t see this
Exposed secrets and open data
The recurring issues are secrets (API keys, tokens, database URLs) left in the code or in a public repl rather than in Replit's secrets manager, and datastores reachable without authentication. An external check reads only your public surface, so it can't see either: they need checking in your project and your code.
What the free Surface Check covers for your Replit app
- HTTPS and HSTS on your custom domain, so traffic can't be silently downgraded to plain HTTP.
- Security headers (Content-Security-Policy, clickjacking protection, nosniff) on your front-end.
- Your TLS certificate's health and how soon it expires.
- Cookie flags (HttpOnly, Secure, SameSite) on any session or auth cookies you set.
- Email spoofing: SPF, DKIM and DMARC on your domain, so attackers can't send email as you.
See your external surface in about a minute
A free, passive snapshot with an A-to-F Surface Score and every issue scored by severity and fix effort. No sign-up, and nothing is stored.
Run the free Surface Check →Frequently asked
Does the check log into my Replit project?
No. It is passive and reads only your public external surface: headers, TLS, cookies and DNS. It never signs in and never reads your code or data.
Where should my secrets live?
In Replit's secrets manager (environment variables), never committed into the code or left in a public repl. Any secret that has been public should be rotated.
How would I know if my data is open?
It won't show as an error, which is the problem. It has to be checked against your datastore's access rules directly; a full Secvura review checks this as standard.
Is it free?
Yes, free and with no sign-up, with an A-to-F Surface Score and every issue scored by severity and fix effort.
More free checks