How to fix npm ERR! 426 Upgrade Required in npm

npmBEGINNERHIGHUpdated Dec 6, 2025· 161 views

The HTTP 426 Upgrade Required error occurs when the npm registry requires a different protocol version. This usually indicates the need to update npm or Node.js to support newer registry features.

Quick fix

Fixes npm ERR! 426 Upgrade Required

node --version
npm --version
  1. Check npm and Node.js versions
  2. Update npm
  3. Update Node.js
  4. Check TLS version support
npm — error
node --version
npm --version
npm ERR! 426 Upgrade Required

What this error means

HTTP 426 indicates the server refuses to process the request using the current protocol and requires the client to upgrade. In npm's context, this typically means your npm version is too old and doesn't support the current registry protocol or security requirements. This error has become more common as npm has tightened security requirements, particularly around TLS versions and authentication methods.

Typical symptoms

  • npm install fails with 426 error
  • Error started without changing anything
  • Old Node.js/npm version in use
  • CI/CD suddenly failing
  • Works on newer machines but not older
  • Error mentions protocol or TLS

Common causes

  1. npm version too old
  2. Node.js version deprecated
  3. TLS 1.0/1.1 no longer supported
  4. Old authentication protocol
  5. Registry API version change
  6. Operating system too old for newer TLS
  7. Proxy/firewall blocking protocol upgrade

How to fix "npm ERR! 426 Upgrade Required"

1Check npm and Node.js versions

Verify your versions:

bash
node --version
npm --version

Compare with current LTS versions at nodejs.org.

2Update npm

Upgrade to latest npm:

bash
# Update npm globally
npm install -g npm@latest

# Or use npx
npx npm@latest install
3Update Node.js

Install a supported Node.js version:

bash
# Using nvm
nvm install --lts
nvm use --lts

# Or download from nodejs.org
# Or use your OS package manager
sudo apt update && sudo apt install nodejs
4Check TLS version support

Verify TLS 1.2+ support:

bash
node -e "console.log(process.versions.openssl)"

# Test TLS connection
openssl s_client -connect registry.npmjs.org:443 -tls1_2
5Update CI/CD environment

For pipeline failures:

yaml
# GitHub Actions example
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/setup-node@v4
        with:
          node-version: "20"  # Use current LTS
6Check proxy/firewall settings

Ensure network allows modern protocols:

1. Contact IT about TLS 1.2/1.3 support
2. Check if proxy allows HTTPS properly
3. Verify firewall isn't downgrading connections

Advanced notes

npm registry deprecated TLS 1.0/1.1 in 2019. Ensure your infrastructure supports TLS 1.2 at minimum. For Docker images, use node:lts or node:20 instead of old versions. In enterprise environments, coordinate with security team about TLS policies. Some older operating systems (Windows 7, older macOS) may need updates to support modern TLS.

Frequently asked questions

What does "npm ERR! 426 Upgrade Required" mean?
HTTP 426 indicates the server refuses to process the request using the current protocol and requires the client to upgrade. In npm's context, this typically means your npm version is too old and doesn't support the current registry protocol or security requirements. This error has become more common as npm has tightened security requirements, particularly around TLS versions and authentication methods.
How do I fix "npm ERR! 426 Upgrade Required"?
The HTTP 426 Upgrade Required error occurs when the npm registry requires a different protocol version. This usually indicates the need to update npm or Node.js to support newer registry features.
What causes "npm ERR! 426 Upgrade Required"?
npm version too old Node.js version deprecated TLS 1.0/1.1 no longer supported
Is the "npm ERR! 426 Upgrade Required" error serious?
Yes. This is a high-severity error that usually blocks work until it is fixed, but the steps above resolve it.

Official resources & further reading