00 / Free check for sites made with v0
Your v0 app is live. Is it safe, legal, and solid?
v0 outputs Next.js, so patch level and auth placement matter. Paste the address and in 30 seconds you get a grade, what is wrong in plain words, and the exact text to paste back into v0 to fix it.
PASTE YOUR SITE'S ADDRESSNo signupWe only look, we change nothingYour pages are not stored
01 / What usually goes wrong on v0
The defaults that bite.
These are the mistakes we see most on sites built with v0. Not your fault: they are what the builder does unless you tell it otherwise.
01The Next.js version may be unpatched against the middleware auth-bypass (CVE-2025-29927).
02Authorization is sometimes enforced only in middleware, not in the data layer.
03Secrets can slip into client components.
The fix, in short
Run a patched Next.js version and enforce authorization inside Server Actions and Route Handlers.
02 / What the scan covers
The same 112 checks, whatever built your site.
A sample from each area. See every check.
SECURITY
A-01CRITICAL
Anyone can read your database
Your Supabase table answers to anyone who asks, no login needed. That is your users' data, readable by strangers. We ask once for a count only, never for a row, and report what came back.
A-04CRITICAL
Your Firebase database is open
Your Firebase data can be read without logging in.
S-01CRITICAL
Your master key is inside the page
The Supabase service key sits in your site's code. Whoever reads it owns your whole database, every lock ignored.
EU LEGAL INFORMATION
DE-IMP-01HIGH
No Impressum found
German law expects a provider page on commercial sites (§5 DDG). We say what we found and link the rule. General information, not legal advice.
DE-PRIV-01HIGH
No privacy notice found
EU law expects one (Art. 13 GDPR). We look for a linked page under the usual names. General information, not legal advice.
DE-IMP-04MEDIUM
Impressum is empty until JavaScript runs
The Impressum page exists, but the server sends it almost empty and the details only appear once JavaScript has run. With JavaScript off, in an archive, or to an automated check the page reads as blank. General information, not legal advice.
QUALITY
Q-16LOW
A file could not be checked
Our own request for robots.txt, sitemap.xml or the favicon got no answer, so we say that instead of claiming the file is missing. Costs no points.
Q-01HIGH
Search engines are told to stay away
A noindex tag or header, or a robots.txt that blocks everything, is still on. Preview builds ship with it; a launched site with it is invisible.
Q-05cMEDIUM
Title is still the template default
The tab reads "Vite + React" or "Lovable App". That is the headline of your search result.