Node.js — Check If a Path or File Exists

When interacting with the file system, you may want to check whether a file exists on the hard disk at a given path. Node.js comes with the fs core module allowing you to interact with the hard disk.

This tutorial shows you how to use Node.js to determine whether a file exists on disk.

Node.js Series Overview

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  5. Remove Numbers From a String in JavaScript or Node.js
  6. Get the Part Before a Character in a String in JavaScript or Node.js
  7. Get the Part After a Character in a String in JavaScript or Node.js
  8. How to Check if a Value is a String in JavaScript or Node.js
  9. Check If a String Includes All Strings in JavaScript/Node.js/TypeScript
  10. Check if a Value is a String in JavaScript and Node.js
  11. Limit and Truncate a String to a Given Length in JavaScript and Node.js
  12. Split a String into a List of Characters in JavaScript and Node.js
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  14. Reverse a String in JavaScript or Node.js
  15. Split a String into a List of Lines in JavaScript or Node.js
  16. Split a String into a List of Words in JavaScript or Node.js
  17. Detect if a String is in camelCase Format in Javascript or Node.js
  18. Check If a String Is in Lowercase in JavaScript or Node.js
  19. Check If a String is in Uppercase in JavaScript or Node.js
  20. Get the Part After First Occurrence in a String in JavaScript or Node.js
  21. Get the Part Before First Occurrence in a String in JavaScript or Node.js
  22. Get the Part Before Last Occurrence in a String in JavaScript or Node.js
  23. Get the Part After Last Occurrence in a String in JavaScript or Node.js
  24. How to Count Words in a File
  25. How to Shuffle the Characters of a String in JavaScript or Node.js
  26. Append Characters or Words to a String in JavaScript or Node.js (Coming soon)
  27. Check if a String is Empty in JavaScript or Node.js (Coming soon)
  28. Ensure a String Ends with a Given Character in JavaScript or Node.js (Coming soon)
  29. Left-Trim Characters Off a String in JavaScript or Node.js (Coming soon)
  30. Right-Trim Characters Off a String in JavaScript or Node.js (Coming soon)
  31. Lowercase the First Character of a String in JavaScript or Node.js (Coming soon)
  32. Uppercase the First Character of a String in JavaScript or Node.js (Coming soon)
  33. Prepend Characters or Words to a String in JavaScript or Node.js (Coming soon)
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  4. Add Seconds to a Date in Node.js and JavaScript
  5. Add Month(s) to a Date in JavaScript or Node.js
  6. Add Week(s) to a Date in JavaScript or Node.js
  7. Get the Current Year in JavaScript or Node.js
  8. How to Get a UNIX Timestamp in JavaScript or Node.js
  9. How to Convert a UNIX Timestamp to a Date in JavaScript or Node.js
  10. Add Days to a Date in JavaScript or Node.js
  11. Get Yesterday's Date in JavaScript or Node.js
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  13. Add Hours to a Date in JavaScript or Node.js (Coming soon)
  14. Check If a Date Is Today in JavaScript or Node.js (Coming soon)
  15. Check If a Date is Tomorrow in JavaScript or Node.js (Coming soon)
  16. Check If a Date is Yesterday in JavaScript or Node.js (Coming soon)
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Asynchronously Check if a File Exists in Node.js

The fs module in Node.js comes with a deprecated exists method. It’s recommended not to use this method anymore. Instead, you should use the Fs#access method to check whether a file exists.

Well, Fs#access doesn’t return the desired boolean value (true/false). Instead, it expects a callback with an error as the only argument. The callback support comes from the early days of Node.js where asynchronous operations used callbacks.

Starting in version 10.0, Node.js added support for promises and async/await for the fs module. This tutorial assumes you’re using async/await for flow control of your code. Then, you can use the require('fs').promises version of Fs#access which is usable with async/await.

Here’s a helper method returning the boolean value whether a file exists at the given path:

const { promises: Fs } = require('fs')

async function exists (path) {  
  try {
    await Fs.access(path)
    return true
  } catch {
    return false
  }
}

// Example:
const Path = require('path')  
const path = Path.join(__dirname, "existing-file.txt")

await exists(path)  
// true

Synchronously Check if a File Exists

You may also use the synchronous method Fs#existsSync to check whether a file exists on your hard disk. Please notice that this method blocks the Node.js event loop for other operations while processing the file existence check:

const Fs = require('fs')  
const Path = require('path')

const path = Path.join(__dirname, "existing-file.txt")

Fs.existsSync(path)  
// true

Use the @supercharge/filesystem Package

I’m the maintainer of the @supercharge/filesystem package providing convenient file system utilities. Methods in the @supercharge/filesystem package are async by default and don’t block the event loop.

You may use the exists method to check if a file path exists on your disk:

const Path = require('path')  
const Fs = require('@supercharge/filesystem')

const path = Path.join(__dirname, "existing-file.txt")

await Fs.exists(path)  
// true

Enjoy!


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