---
title: "ERR_SSL_PROTOCOL_ERROR on Chrome: cause and fix"
description: "Chrome disabled TLS 1.0/1.1 outright and enforces certificate transparency, so it fails where older browsers still connect."
canonical: "https://lemwatch.com/errors/err-ssl-protocol-error/on-chrome"
source: "https://lemwatch.com"
---

# ERR_SSL_PROTOCOL_ERROR on Chrome

> Chrome disabled TLS 1.0/1.1 outright and enforces certificate transparency, so it fails where older browsers still connect.

## Why it happens on Chrome

 Chrome disabled TLS 1.0/1.1 outright and enforces certificate transparency, so it fails where older browsers still connect.

## The fix on Chrome

 Open chrome://net-internals/#hsts and clear the domain's HSTS/security state, then Settings → Privacy → Clear browsing data → Cached images and files. If it still fails, the server is offering a protocol Chrome rejects.

## If that didn't fix it

 Chrome has its own failure mode, but ERR_SSL_PROTOCOL_ERROR has a wider set of causes. The most common one overall is: The server only offers TLS 1.0 or TLS 1.1, which every current browser has disabled.

 Enable TLS 1.2 and TLS 1.3 on the origin and remove the deprecated versions. On nginx set `ssl_protocols TLSv1.2 TLSv1.3;` and reload.

## Check your own domain

 The SSL checker reads the live handshake: protocol versions offered, cipher suites, chain completeness and expiry. If it cannot complete the handshake either, the fault is server-side and not your browser.

## Frequently asked questions

### Why does ERR_SSL_PROTOCOL_ERROR happen on Chrome?

 Chrome disabled TLS 1.0/1.1 outright and enforces certificate transparency, so it fails where older browsers still connect.

### How do I fix ERR_SSL_PROTOCOL_ERROR on Chrome?

 Open chrome://net-internals/#hsts and clear the domain's HSTS/security state, then Settings → Privacy → Clear browsing data → Cached images and files. If it still fails, the server is offering a protocol Chrome rejects.

### What does ERR_SSL_PROTOCOL_ERROR mean?

 Chrome tried to start an encrypted connection and the server answered with something that is not valid TLS. In almost every case the server is offering a protocol version or cipher the browser refuses, the certificate is broken, or something on the network is intercepting the handshake.


## Related

- [All causes of ERR_SSL_PROTOCOL_ERROR](https://lemwatch.com/errors/err-ssl-protocol-error)
- [All website error codes](https://lemwatch.com/errors)
- [ERR_SSL_PROTOCOL_ERROR on Mac](https://lemwatch.com/errors/err-ssl-protocol-error/on-mac)
- [ERR_SSL_PROTOCOL_ERROR on Windows](https://lemwatch.com/errors/err-ssl-protocol-error/on-windows)
- [ERR_SSL_PROTOCOL_ERROR on Nginx](https://lemwatch.com/errors/err-ssl-protocol-error/in-nginx)
- [Free SSL certificate check](https://lemwatch.com/tools/ssl-checker)
- [ERR_SSL_PROTOCOL_ERROR on iPhone](https://lemwatch.com/errors/err-ssl-protocol-error/on-iphone)
- [ERR_SSL_PROTOCOL_ERROR on Android](https://lemwatch.com/errors/err-ssl-protocol-error/on-android)