NET::ERR_CERT_AUTHORITY_INVALID — How to Fix [2026 Guide]

Enterno.io Editorial Team

NET::ERR_CERT_AUTHORITY_INVALID Error: Causes and Solution

By Anatoly Oshmanovsky · Updated Apr 17, 2026

TL;DR:

NET::ERR_CERT_AUTHORITY_INVALID means Chrome/Edge does not trust the site's SSL certificate — the certificate chain does not lead to a trusted root CA. 90% of cases are caused by a self-signed certificate, expired root CA, or incomplete chain. Fix: install a certificate from a public CA (Let's Encrypt, DigiCert) and configure the full chain on your server.

This error blocks access to your site and scares visitors away. In 90% of cases the problem is server-side — misconfigured SSL certificate. We cover all causes and give a step-by-step fix.

Try it now — free →

What does NET::ERR_CERT_AUTHORITY_INVALID mean

When a browser opens an HTTPS site, it validates the SSL certificate chain: site cert → intermediate CA → root CA. If any link is untrusted or missing, Chrome shows NET::ERR_CERT_AUTHORITY_INVALID.

This doesn't mean the site is hacked. Most commonly the cause is server administration:

Self-signed certificate (not issued by a public CA)
Root CA not installed in the OS
Incomplete certificate chain on server (missing intermediate CA)
Expired root CA (rare, happens with legacy certificates)
Certificate from an untrusted CA (example: COMODO, no longer in chrome root store)

How to fix (step-by-step)

Check your SSL certificate online — use the Enterno.io SSL checker. Enter your domain to see the full chain, issuer and any issues.
If the certificate is self-signed — replace with Let's Encrypt (free) or a commercial CA.
If the chain is incomplete — add the intermediate CA to your bundle. For nginx: ssl_certificate /path/to/fullchain.pem; (not just cert.pem).
Check Root CA in browser — Chrome uses its own trust store, not the system one. Update Chrome.
Clear browser SSL cache — Chrome: chrome://net-internals/#ssl → Flush sockets.

Check SSL certificate →

CertificateExpiry, issuer, domains (SAN)

ChainIntermediate and root CA validation

TLS ProtocolTLS version and cipher suite

VulnerabilitiesHeartbleed, POODLE, weak ciphers

Why teams trust us

TLS 1.3

supported

Full

CA chain check

<2s

result

30/14/7

days-to-expiry alerts

How it works

Enter domain

TLS chain verified

Expiry date & vulnerabilities

What Does the SSL Check Cover?

SSL/TLS is the encryption protocol that protects data between the browser and server. Our tool analyzes the certificate, chain of trust, TLS version, and knownvulnerabilities.

Certificate Details

Issuer, validity period, signature algorithm, covered domains (SAN), and validation type (DV/OV/EV).

Chain of Trust

Full chain verification: from leaf certificate through intermediates to root CA.

TLS Analysis

Protocol version (TLS 1.2/1.3), cipher suites, Perfect Forward Secrecy (PFS) support.

Expiry Alerts

Set up a monitor — get Telegram and email alerts 30/14/7 days before expiration.

DV vs OV vs EV Certificates

DV (Domain Validation)

Confirms domain ownership only
Issued in minutes automatically
Free via Let's Encrypt
Suitable for most websites
Most common certificate type

OV / EV

Organization (OV) or Extended Validation (EV)
Issued in 1-5 business days
Costs $50 to $500/year
For finance, e-commerce, government sites
Increases user trust

Who uses this

DevOps

SSL certificate monitoring

Security

TLS config audit

SEO

HTTPS as ranking factor

E-commerce

customer trust

Common Mistakes

❌

Expired certificateBrowsers block sites with expired SSL. Set up auto-renewal or monitoring.

❌

Incomplete certificate chainWithout intermediate CA, some browsers and bots cannot verify the certificate.

❌

Mixed content on HTTPS siteHTTP resources on an HTTPS page — the browser lock icon disappears, reducing trust.

❌

Using TLS 1.0/1.1Legacy TLS versions have known vulnerabilities. Use TLS 1.2+ or 1.3.

❌

Domain mismatch in certificateThe certificate must cover all site domains, including www and subdomains.

Best Practices

✓

Set up auto-renewalLet's Encrypt + certbot with cron — certificate renews automatically every 60-90 days.

✓

Enable HSTSStrict-Transport-Security header forces browsers to always use HTTPS.

✓

Use TLS 1.3TLS 1.3 is faster (1-RTT handshake) and safer — legacy ciphers removed.

✓

Monitor expiration datesCreate a monitor on Enterno.io — get notified well before expiration.

✓

Verify chain after renewalAfter certificate renewal, confirm that intermediate certificates are installed.

Get more with a free account

SSL certificate monitoring, check history and alerts 30 days before expiry.

Learn more

How-to

Glossary

Research

TLS Cipher Suites 2026: Distribution Report

Errors

Alternatives

Frequently Asked Questions

Is it safe to bypass NET::ERR_CERT_AUTHORITY_INVALID?

No. Chrome shows this error because it cannot verify site authenticity. Bypassing (chrome://flags or "thisisunsafe") makes your connection vulnerable to man-in-the-middle attacks. Only safe for your own dev servers.

Why does the error show only in Chrome but Firefox works?

Chrome and Firefox use different trust stores. Chrome uses its own root CA list (chrome-root-store), Firefox uses Mozilla's CA list. If your CA is in Mozilla but not Chrome, the error appears only in Chrome.

Can I fix this client-side?

If only one site shows the error — fix server-side. If all HTTPS sites error out — check system clock, update Chrome, check corporate proxy (may be inspecting certificates).

How can I check SSL chain online?

Use the <a href="/en/ssl">Enterno.io SSL/TLS checker</a> — enter domain, get full certificate chain, expiry, issuer and warnings. Free, no signup.

Is Let's Encrypt free — will it be trusted?

Yes. Let's Encrypt is included in all major trust stores (Chrome, Firefox, Safari, Edge). Certificates valid for 90 days with automatic renewal via certbot.