Does Replit have a built-in security scanner?

Yes, in layers. Replit's Security Agent audits your codebase for code, dependency, and privacy vulnerabilities.^[1] Separately, automatic dependency scans check your project's packages against public vulnerability records.^[2] A third, lighter check runs inline while the Agent is building your app.

All of these feed into the Project Security Center, which Replit describes as "the central place to find and fix security and privacy vulnerabilities in a Replit App."^[4] When a newly published vulnerability affects your packages, Replit sends at most one email per Workspace that summarizes all affected projects, so one alert can cover several apps.^[4]

The full Agent security scan reads your project's source code and flags code, dependency, and privacy vulnerabilities.^[1] It is available to all paid Replit builders, so a free account should not expect it.^[3] The dependency scans are a different tool: they match your packages against public vulnerability records rather than reading your own logic.^[2]

The table shows how Replit's own checks differ in what they test. The key column is the middle one.

The Agent scan does not attack your deployed app the way an outsider would. Replit's overview says to "use a Level 3 black-box pen test when you also need to test the running app from the outside," which places live-app testing in a separate offering.^[1] The inline check is even narrower: Replit calls it "an early, lightweight check in the Agent workflow rather than a full codebase review."^[2]

That matters because many real problems only show up at runtime. A user who can open another user's records, an admin page reachable without the admin role, or a misconfigured environment can all look fine in source code. Under Replit's shared responsibility model, catching those is on you: you are responsible for your application's contents and for configuring the tools Replit provides.^[5] For a deeper breakdown, see what the Replit Security Agent covers and what it leaves to you.

No, and Replit says so. Its docs state that "a scan is not a complete security review" and tell you to use it "alongside code review, tests, dependency review, and checks of the running app."^[3] Replit's own tutorial adds that "AI-generated code still needs security review."^[6]

The missing piece is an outside-in test of the app as it actually runs. If you add one, two habits make it safer and more useful:

• Test a copy, not your live workspace. Clone or fork the Replit project and point the outside scanner at the copy's URL, so test data and admin actions never touch production.
• Give the tester two roles. Provide at least two accounts with different privilege levels, such as Admin and User, so authorization and privilege escalation get tested properly. A source-code scan can't log in as both and compare what each one sees.

BattleTester runs that outside check: it logs in and explores your app like a real user, then gives you a detailed report and AI instructions you can hand to your agent to fix the issues. It is a complementary check, not a comprehensive security audit, and it does not replace a professional assessment. You can start with a free surface scan and no credit card.

Replit says it is SOC 2 Type II certified after a 12-month security audit with zero exceptions or comments.^[7] That is Replit's own statement about its own controls. It tells you the platform is run carefully, not that any app built on it is secure.

Replit's shared responsibility page draws the line clearly. Replit is responsible for the security of the Replit Agent, platform, and infrastructure your workload runs on.^[5] Your auth logic, database rules, stored secrets, and what your users can access sit on your side of that line. Past incidents show what can go wrong on either side, covered in what actually happened in Replit's 2023 and 2025 security incidents.

Replit handles transport encryption for you: it uses HTTPS by default for all applications.^[8] Most of the rest is yours, and Replit's checklist says you should implement more security measures for your specific application needs.^[8] Before you ship, run through these:

1. Sanitize user input. Replit tells builders to always validate and sanitize user input to prevent cross-site scripting (XSS).^[8]
2. Review AI-written code by hand around authentication, database queries, secrets, and data handling, since that code still needs security review.^[6]
3. Run the Agent security scan if you are on a paid plan, and fix what the Project Security Center reports.^[3]
4. Act on dependency alerts when the Workspace email arrives.
5. Test the running app from outside, on a cloned copy, with at least two user roles.

For the longer version, use the Replit security checklist to run before you ship. If your outside test flags missing headers, what a security headers check tells you and what it misses explains how much weight to give them.

If you want a deeper test, BattleTester's full pentest costs $15 and is charged only if the scan finds High or Critical vulnerabilities. If it finds none, you are not charged and the report stays fully accessible.