Free Mixed Content Checker
Free tool
Scans your HTTPS page for scripts, images, iframes and other resources loaded over plain http:// that browsers block or upgrade. Pinpoints each offender with step-by-step fixes.
- HTTP resource detection
- Fix guidance
No credit card requiredRead-only, no exploitationNo setup or code required
Used by 5,000+ developers and engineering teams
What you get for free
18 core security checks via this tool, passive scans, step-by-step remediation, security score on every result.
What Essential adds from €199/mo
Pentest credits every month, +17 advanced checks, weekly passive scans, email alerts and audit-ready PDFs for SOC 2 / ISO 27001 / PCI.
What is mixed content?
Mixed content occurs when an HTTPS page loads resources (images, scripts, stylesheets, iframes) over HTTP. Modern browsers block or degrade these requests, breaking functionality and compromising security.
What this checker validates
- Resources loaded over http:// on your HTTPS page
How to fix mixed content
- Replace all
http://URLs withhttps:// - Update CDN and library URLs to HTTPS versions
- Fix hardcoded links in templates, CSS, and JavaScript
- Use CSP
upgrade-insecure-requestsas temporary mitigation
Implementation examples
Once you've identified the gap, applying the fix is straightforward. Here are the configurations developers reach for most often.
Nginx
add_header Content-Security-Policy "upgrade-insecure-requests" always;Apache
Header always set Content-Security-Policy "upgrade-insecure-requests"Node.js (Express + Helmet)
app.use(
helmet.contentSecurityPolicy({
directives: {
upgradeInsecureRequests: [],
},
}),
)Next.js (next.config.mjs, works on Vercel)
const nextConfig = {
async headers() {
return [
{
source: "/(.*)",
headers: [
{ key: "Content-Security-Policy", value: "upgrade-insecure-requests" },
],
},
]
},
}
export default nextConfigOn Netlify, the same headers go in a public/_headers file, and most other hosts have an equivalent headers setting.
Tool-specific questions
Why do browsers block mixed content?
Browsers block mixed content to prevent man-in-the-middle attacks where HTTP resources could be modified in transit, compromising the security of the HTTPS page.
What's the difference between active and passive mixed content?
Active mixed content (scripts, stylesheets, iframes) is blocked completely. Current browsers auto-upgrade passive mixed content (images, audio, video) to HTTPS, or block it if that fails. Both should be fixed.
Can I use protocol-relative URLs (//example.com)?
They inherit the page's scheme, so on an HTTPS page they load over HTTPS. Explicit https:// URLs are still clearer and avoid surprises if the same markup is ever served over HTTP.
How does CSP upgrade-insecure-requests help?
The upgrade-insecure-requests directive tells browsers to try HTTPS for HTTP resources, but it only works if the resource server supports HTTPS. Use it as a temporary bridge while fixing sources.
What if a third-party service doesn't support HTTPS?
Contact the service provider to request HTTPS support, or find an alternative service that supports HTTPS. Never rely on mixed content for production websites.
Why Barrion
Built for the engineers who already have enough to fix.
Speed
Fast results
Instant analysis with a detailed report. You see findings as the scan runs, not after.
Coverage
Comprehensive checks
The full passive scan runs 18 checks on the free plan, covering TLS, headers and cookies. Paid plans run 35+ and add CORS, DNS, email auth and more.
Action
Step-by-step fixes
Every finding ships with the exact remediation step for your framework. Hand it to the engineer who owns the surface.
Other tools
More free checks, for the rest of your surface.
Complete Security Scan
Complete website security analysis with comprehensive vulnerability detection
Pre-Pentest Security Scan
Passive scan that catches the misconfigurations a pentester finds first. Use it before a manual engagement to clear the easy issues.
Security Compliance Checker
Run general security checks relevant to PCI DSS, HIPAA, SOC 2, ISO 27001 and GDPR. Findings aren't mapped to specific requirements.
WAF Checker
Detect which WAF or CDN sits in front of your site from the signatures in its response. Passive, no attack payloads.
Security Headers Test
Check your website's HTTP security headers configuration
TLS/SSL Security Checker
Validate your SSL/TLS configuration and certificate setup
Related guides
Go deeper on the same topic.
FAQ
Frequently asked.
What is Barrion?
Barrion runs continuous, agentic AI penetration tests of web applications and APIs. AI agents test your app the way an attacker would, safely, on a schedule or on demand. Findings are checked against the live app before they're reported, and tracked across runs as new, still open, resolved or regressed. From Standard level up, a security engineer reviews each report. Barrion AB is based in Gothenburg, Sweden. A free passive scan is the quickest way to start.
How safe is Barrion to use for security testing?
AI pentests send real test requests, so they're rate-limited and non-destructive, and you approve the exact scope before a single request goes out. You can point them at staging too. The free passive scan only reads your live app. It never submits forms, brute-forces endpoints or touches anything that changes state, so it's safe to run against production.
What types of security issues does Barrion identify?
AI pentests look for the issues an attacker could exploit, like SQL injection, cross-site scripting and broken access control. Findings are checked against your live app, and confirmed ones come with the request and response that prove them. Anything we couldn't confirm is clearly marked and capped in severity. The passive scan catches misconfigurations in TLS and HTTPS, security headers, cookie flags, CORS policy, DNS records, email authentication (SPF, DKIM, DMARC) and network exposure.
What specific security checks does Barrion perform?
Barrion covers two surfaces. AI pentesting is the active part: specialist agents chain requests to find exploitable flaws such as SQL injection, cross-site scripting and broken access control. Findings are checked against your live app, and confirmed ones come with the request and response that prove them. The passive scan is read-only and safe to point at production. On paid plans it runs 35+ checks (18 on the free plan): transport security (HTTPS, HSTS, TLS version, cipher suites, certificate expiry, hostname and chain validity, OCSP stapling), HTTP response headers (Referrer-Policy, Permissions-Policy, X-Content-Type-Options, Content-Type, server information disclosure), CSP and framing (Content-Security-Policy, bypass detection, Trusted Types, X-Frame-Options), cross-origin policy (COOP, COEP, CORP and the full CORS header set), cookie flags and anti-CSRF tokens, mixed content, vulnerable JavaScript libraries, DNS records including DNSSEC and CAA, email authentication (SPF, DKIM, DMARC), open ports and subdomain takeover. Findings from both are ranked by severity and come with step-by-step remediation.
Will my auditor or enterprise customers accept the pentest report?
The report maps every finding to OWASP WSTG, a security engineer reviews it from Standard up and signs it off from Deep up, and a free retest shows what you fixed. Teams use it as evidence for SOC 2, ISO 27001 and NIS2 work. Whether it's accepted is up to your auditor.
How often does Barrion test my app?
Continuously or on demand. On the Business plan you save a pentest and it reruns daily, weekly, monthly, quarterly, every six months, yearly or on your own rhythm. On any plan you can start a pentest or a passive scan on demand. A passive scan also runs on a schedule and alerts you when something new shows up.
Is Barrion suitable for security testing of all business sizes?
Yes. Solo developers often start with the free passive scan and a single pentest. Teams with several apps run pentests on a schedule, and it fits alongside the tools you already run.
How does Barrion handle data security and privacy during security testing?
Passive scans are read-only: they only look at what your app already exposes publicly. For AI pentests we keep the findings in your report, and confirmed findings include the request and response behind them, so you can review and reproduce them. Test credentials you add are encrypted. Barrion is hosted in Sweden, data is stored in the EU and AI processing runs in the EU. Our trust page lists every subprocessor. Pentests are rate-limited and only run inside the scope you approve.
What if I'm not satisfied with Barrion's security testing service?
You can cancel anytime in the dashboard, and paid plans carry a 14-day refund window from the first charge. If something isn't right, contact us and we'll make it work for your team.
How does Barrion help with SOC 2, ISO 27001, NIS2, and other compliance frameworks?
Barrion's pentest reports come as PDF, XLSX and JSON, mapped to all 97 OWASP WSTG test cases, with engineer review from Standard up, sign-off from Deep up and a free retest after fixes. Teams use them as evidence that supports SOC 2, ISO 27001, PCI DSS and NIS2 work. Whether a report is accepted is up to your auditor or customer.
Anything else? Email contact@barrion.io.