Node.js path Module

What is path Module in Node.js?

The path module builds and inspects file paths correctly on every operating system, handling the difference between forward and backslashes so your code works on Windows, macOS and Linux alike.

path Module example

import path from 'node:path';

path.join('uploads', 'resumes', 'cv.pdf');   // uploads/resumes/cv.pdf
path.resolve('uploads', 'cv.pdf');           // absolute from cwd
path.extname('resume.pdf');                  // .pdf
path.basename('/a/b/resume.pdf');            // resume.pdf
path.basename('/a/b/resume.pdf', '.pdf');    // resume
path.dirname('/a/b/resume.pdf');             // /a/b
path.parse('/a/b/resume.pdf');               // { root, dir, base, ext, name }

Key points to remember

• join concatenates segments; resolve produces an absolute path.
• Never build paths with string concatenation and slashes.
• path.normalize collapses .. and . segments.

Common mistakes with path Module

• Joining user input into a path without validation — a "../" segment escapes the intended directory.
• Hardcoding forward slashes and breaking on Windows.