Fix EACCES: permission denied on /etc/hosts (2026)

EACCES: permission denied on /etc/hosts occurs when a Node.js script, CLI tool, or shell command attempts to write to the hosts file without root administrator privileges. This system file is write-protected by default to prevent unauthorized network hijacking.

How to fix EACCES: permission denied on /etc/hosts

To fix EACCES: permission denied on /etc/hosts, run your command with sudo, use echo "127.0.0.1 myapp.test" | sudo tee -a /etc/hosts for shell redirections, or integrate a privilege elevation helper (such as sudo-prompt) into your Node.js scripts.

Understanding /etc/hosts file permissions

On macOS and Linux, inspect the current permissions of the hosts file:

ls -la /etc/hosts

The terminal output typically shows:

-rw-r--r--  1 root  wheel  213 Aug 17 10:00 /etc/hosts

Breaking down the permission bits:

• Owner (root): Read and write access (rw-).
• Group (wheel or root): Read-only access (r--).
• All other users: Read-only access (r--).

When a Node.js process calls fs.writeFileSync('/etc/hosts', data), the operating system kernel denies the syscall and returns POSIX error code EACCES (Error Access).

See our guide on hosts file permission denied on Mac for platform-specific details.

4 ways to resolve the error

1. The shell redirection trap (and how to fix it)

If you attempt to append an entry using:

# This will fail:
sudo echo "127.0.0.1 api.local.test" >> /etc/hosts

The terminal will still print permission denied. This happens because sudo only elevates the echo command, while the append redirection >> is executed by your unprivileged user shell.

The correct command:

echo "127.0.0.1 api.local.test" | sudo tee -a /etc/hosts > /dev/null

The tee command runs with elevated sudo privileges and writes to the file directly using the -a (append) flag.

2. Run your Node.js build script with sudo

For standalone provisioning or setup scripts:

sudo node ./scripts/update-hosts.js

On Windows (PowerShell): Open PowerShell with Run as administrator before executing your setup command.

3. Elevate privileges programmatically in Node.js

Running an entire development suite or test runner as root exposes your system to risks from third-party npm packages. Instead, isolate the hosts file write operation:

import sudo from 'sudo-prompt';

const options = {
  name: 'Local Hosts Manager'
};

const domainEntry = '127.0.0.1 myproject.test';
const command = `sh -c 'echo "${domainEntry}" >> /etc/hosts'`;

sudo.exec(command, options, (error, stdout, stderr) => {
  if (error) {
    console.error('Failed to update hosts file:', error);
    return;
  }
  console.log('Domain added to hosts file successfully.');
});

4. Restore standard system permissions

If file permissions on /etc/hosts were modified accidentally:

On macOS:

sudo chown root:wheel /etc/hosts
sudo chmod 644 /etc/hosts

On Linux (Ubuntu/Debian):

sudo chown root:root /etc/hosts
sudo chmod 644 /etc/hosts

Why you should NEVER run chmod 777 on /etc/hosts

Applying chmod 777 /etc/hosts makes the file writable by every user and background process on your machine.

• Any unvetted npm package or malicious script could silently redirect critical domains (such as package registries or banking sites) to hostile IP addresses.
• Operating system security agents may discard hosts file rules if permissions are detected as insecure.

Safe hosts management with ToggleHosts

Rather than repeatedly running manual terminal commands with sudo, a native hosts manager like ToggleHosts groups your domains into toggleable environments and uses a hardened, privileged helper to apply changes safely.