TL;DR: The best vibe coding security tools are a stack, not a single pick. You need four layers: a secret scanner (gitleaks), a dependency checker (npm audit), a headers checker (Mozilla Observatory or our free tool), and a URL-based readiness scanner for your live app. Each layer catches what the others miss. Every layer has a free option, listed below.
If you built your app with Lovable, Bolt, Cursor, or Replit, the working part works. The safe part is a separate job. AI tools ship features fast. They skip the guard rails an engineer would add without being asked.
This roundup is sorted by category, not by brand. For each layer you get: what it catches, what it misses, and the free tool to run first. We sell one of these layers. We will be plain about which one, and about what it cannot see.
Why one tool never covers it
AI-written code fails in more than one place at once. CMU's SusVibes study found 61% of AI-written code had at least one security flaw. Symbiotic Security scanned 1,072 AI-built apps. 98% had at least one flaw. 16% had critical issues.
Those flaws live in different places. A key in your git history. A bad package deep in your lockfile. A missing header on your server. An open table behind your API. No single tool reads all four places. Four places, four checks. That is why the honest answer to "what is the best tool" is a short stack of them.
The four layers at a glance
| Layer | What it catches | What it misses | Free option |
|---|---|---|---|
| Secret scanner | Keys, tokens, and passwords in your code and git history. | Flaws in logic, packages, or the live deploy. | gitleaks. |
| Dependency checker | Packages with known flaws in your lockfile. | Your own code. Secrets. Server config. | npm audit. |
| Headers checker | Missing CSP, HSTS, X-Frame-Options, and friends. | Everything behind the response headers. | Mozilla Observatory, or our headers checker. |
| URL-based readiness scanner | What your live app exposes to the public: leaked keys, open endpoints, no rate limits, weak headers. | Anything that needs repo access, like internal logic. | Our free scan. |
Layer 1: secret scanners
AI tools hardcode keys. Not out of malice — the shortest path to working code puts the key next to the call. Once a key is committed, it stays in your git history. Deleting the file does not remove it.
gitleaks is the free standard here. It scans your repo and its full history for key patterns. Stripe, Supabase, AWS, and hundreds more. We run gitleaks inside our own audit engine. This is not a courtesy pick. It is part of how we work.
One rule to keep: if gitleaks finds a live key, rotate the key. Removing it from the code does not un-leak it. Our guide on finding exposed secrets in AI bundles covers the browser-side check too. That one finds keys sitting in the code your visitors download.
Layer 2: dependency checkers
AI builders add a package every time they need a shortcut. Nobody checks the list after that. Some of those packages carry known flaws. Some are years old on the day they land.
npm audit ships with Node and takes one command. It checks your lockfile against a public flaw list. Then it prints what to upgrade. For Python projects, pip-audit does the same job. Run it before every launch. Run it again after any AI build session that touched packages.
A related habit: read your lockfile diff when the AI adds packages. If you do not know why a package is there, ask the tool that added it. It will tell you.
Layer 3: headers checkers
Security headers are the cheapest fix on this page. CSP, HSTS, X-Frame-Options — one config block on your host. Nothing breaks on screen when they are missing. That is why AI tools skip them. What you lose is the browser's own guard. It is what keeps a script injection from turning into session theft.
Mozilla Observatory is the well-known free checker. Our own security headers checker does the same check with a plain-English fix list per header. Either way, this takes under a minute. Do it today.
Just keep it in scale. Headers are the easy part, not the whole job. A perfect header score on top of an open database is still an open database.
Layer 4: URL-based readiness scanners
This is the layer we build. So here is the honest version.
A URL-based scan tests your live, deployed app from the outside — the same view an attacker gets. It looks for keys readable in your bundle. It probes endpoints that answer without auth. It checks rate limits under load, headers, and platform tells. It can also tell which AI tool built the app. Then it checks that platform's known weak spots.
The load engine reports missing throttles word for word as "No rate limiting detected under concurrent load." (k6Scanner.js:170). It is one of the most frequent findings we raise.
What it cannot do: see inside your repo. A URL scan cannot read your database policies line by line or review your auth logic. It sees what is exposed, which is where real attacks start — but it is one layer, like everything else on this page. Across 100 AI-built apps we scanned, the average score was 42/100. The free scan gives you yours in about 30 seconds. Our methodology page lists each check.
Free database and API checks
Vibe-coded apps lean on Supabase and Firebase. The single most common deep gap we find is Row Level Security left off. CVE-2025-48757 exposed 170+ Lovable apps that way. The Quittr Firebase breach showed the same failure on the Firebase side.
Three of our free tools cover this layer, no signup:
- Supabase RLS checker — tests whether your tables answer to the public anon key.
- RLS policy checker — checks your policies for the
USING (true)trap that allows everyone. - API rate limit checker — hits one endpoint and tells you if anything throttles it.
If any of these fail, fix the database first. Our Supabase RLS guide walks through owner-scoped policies step by step.
Where paid audits fit
Run the free layers first. If they come back clean and your app is a side project, you may be done. If real users and real money touch the app, a full audit earns its price. It reviews all four dimensions: security, reliability, performance, and monitoring. It ranks every finding, so you fix in the right order.
| Option | Price | Best for |
|---|---|---|
| Free scan | $0 | First pass on any live URL. Score out of 100. |
| Launch Readiness Audit | $499, one time | Pre-launch. Branded report. Ranked fix plan with time estimates. Benchmark vs 200+ audited apps. Senior review of every finding. |
| Daily scans | From $149/mo | Ongoing checks after launch, weekly digest. |
| Done-for-you setup | $1,999 | We ship the fixes as PRs you approve. Leads into a monthly retainer. |
Full details sit on the pricing page, and you can read a sample report before spending anything.
The compliance layer
Security tools handle attackers. Rules are a second front. If your app has EU users, GDPR applies no matter where you sit. If it has an AI feature, the EU AI Act's transparency rules (Article 50) apply from August 2, 2026. Users must be told they are talking to an AI. Fines for that breach run up to €15 million or 3% of global turnover.
None of the tools above check any of that. Our Compliance Wing does, and the GDPR guide for vibe-coded apps covers the data side in plain words.
Start with the layer that takes 30 seconds
Scan your live URL free. Launch Readiness Score out of 100. No code access, no signup.
Run the free scanFAQ
What are the best vibe coding security tools for a solo founder?
Start free. Run gitleaks on your repo, npm audit on your packages, a headers check on your domain, and a URL-based readiness scan on your live app. All four take under an hour and cost nothing.
Is a free security scanner enough before launch?
It is the right start, not the finish. Free scans catch what is exposed to the public. They cannot see your database policies from the inside or review your auth flow line by line. Treat each one as a layer.
What does gitleaks do?
It scans your git history for keys, tokens, and passwords that were ever committed. AI tools hardcode keys often, so this one check pays off fast. If it finds a live key, rotate the key. Deleting the file is not enough.
Do I need a dependency checker for an AI-built app?
Yes. AI builders add packages every time they need a shortcut. Nobody checks the list after that. A checker like npm audit flags the ones with known flaws in seconds.
How much does a full security audit cost in 2026?
Our free scan is $0. The full Launch Readiness Audit is $499, one time. Daily scan plans start at $149 per month. Done-for-you setup is $1,999 and leads into a monthly retainer.
Can I fix the findings myself?
Often, yes. Headers are one config block. Secret moves and rate limits are small code changes. Database policies take more care. Any AI tool will write the fix once a scan names it.
The full checklist behind this stack lives in our vibe coding security guide. The short version fits in one line: the code works, the defaults do not. Four free checks close most of the gap — and the first one takes 30 seconds.