npm ERR! code EPERM

npm cannot perform the requested operation due to file system restrictions.

Frequently documented in developer and vendor support forums.

• File locked by another process
• Antivirus blocking npm
• Windows file permission issues

1. Close all editors and terminals, retry
2. Temporarily disable antivirus
3. Run terminal as administrator

Last reviewed: March 2026 How we review solutions

EPERM stands for "Error PERMission" and means the operating system denied npm the right to perform a file system operation—typically deleting, renaming, or writing a file inside node_modules. Unlike EACCES, which means "you do not have access to this file at all," EPERM specifically means "the operation you attempted is not permitted on this file, even though you can access it." On Windows, this distinction is critical: Windows Explorer or another process may have a handle on a file, which prevents npm from modifying it even though the file permissions allow writes. Antivirus software is the single most common cause on Windows—real-time protection scanners hold brief locks on files as npm writes them, and if npm tries to delete or rename the file during the scan, the OS returns EPERM. On Linux and macOS, EPERM typically means you are running npm install in a directory owned by root (like /usr/local) without sudo, or that immutable flags are set on files. The error is especially frustrating because it often appears to be random—it fails on a different file each time because the race condition between npm's file operations and the locking process depends on timing.

1. Close all other applications that access node_modules (IDEs, dev servers)
2. Disable antivirus real-time protection temporarily and retry
3. Delete node_modules and reinstall: rm -rf node_modules && npm install
4. On Windows, check for file locks: handle.exe (from Sysinternals)
5. Check file ownership: ls -la node_modules/.package-lock.json

Windows Controlled Folder Access blocking npm

Windows Ransomware Protection blocks unauthorized applications from modifying protected folders. If your project is in Documents or Desktop, node.exe may be blocked. Add node.exe to the Controlled Folder Access allowed apps list in Windows Security.

npm install run as root created root-owned files

Running sudo npm install creates files owned by root inside node_modules. Subsequent non-sudo npm install attempts fail with EPERM because your user cannot modify root-owned files. Fix with sudo chown -R $(whoami) node_modules and never use sudo for npm install in project directories.

OneDrive or iCloud syncing node_modules

Cloud sync tools may set special attributes on files or hold them open during sync. If your project is in a synced folder, npm file operations conflict with the sync process. Move the project outside the synced directory or add node_modules to the sync exclusion list.

Why does Windows cause EPERM?

Windows has stricter file locking that can conflict with npm operations.

How do I find what is locking files?

Use Process Explorer or handle.exe to find processes locking files.

What is the difference between EPERM and EACCES?

EACCES means the file system permissions do not allow the operation (wrong user or group). EPERM means the operation itself is not permitted regardless of permissions—usually because the file is locked by another process, has immutable attributes, or the OS enforces additional restrictions.

Why does EPERM only happen sometimes?

The error is timing-dependent. Antivirus scans and IDE file watchers lock files briefly. If npm tries to modify the file during that brief window, it gets EPERM. On the next attempt, the lock may have been released. This makes the error appear random.

Should I use sudo to fix EPERM?

Never use sudo for npm install in a project directory—it creates root-owned files that cause more permission problems later. Fix the root cause: close locking processes, disable antivirus scanning of node_modules, or fix file ownership.

• npm install – Official npm Docs
• package.json Reference – npm Docs