How to Install a Custom Chrome Extension

Follow this step-by-step guide to install your custom Adform Flow extension in Google Chrome.

Prerequisites

1

Google Chrome browser (version 88 or later recommended)

2

The extension files (usually provided as a .zip file or folder)

3

Administrator privileges on your computer (may be required)

Step 1Open Chrome Extensions Page

There are several ways to access the Chrome extensions page:

Method 1: Using the menu

  1. Click the three dots menu (⋮) in the top-right corner of Chrome
  2. Go to More tools → Extensions

Method 2: Using the address bar

Type chrome://extensions/ in the address bar and press Enter

Chrome menu showing More tools → Extensions navigation

Chrome menu → More tools → Extensions

Step 2Enable Developer Mode

To install custom extensions, you need to enable Developer mode:

  1. Look for the “Developer mode” toggle in the top-right corner of the Extensions page
  2. Click the toggle to turn it ON
  3. You should see additional buttons appear: “Load unpacked”, “Pack extension”, and “Update”
Enabled Developer Mode

Enabled Developer Mode

Note: Developer mode allows you to install extensions from outside the Chrome Web Store. Only enable this for trusted extensions.

Step 3Prepare Your Extension Files

Before loading the extension, make sure your files are properly prepared:

If you have a .zip file:

  1. Extract the .zip file to a folder on your computer
  2. Remember the location of this folder
  3. Ensure the folder contains a manifest.json file

If you already have a folder:

  1. Verify the folder contains a manifest.json file
  2. Note the full path to this folder
Folder structure with manifest.json

Folder structure with manifest.json

Step 4Load the Extension

Now you can install your custom extension:

  1. Click the “Load unpacked” button that appeared after enabling Developer mode
  2. A file browser window will open
  3. Navigate to and select the folder containing your extension files (the one with manifest.json)
  4. Click “Select Folder” or “Open”
Load unpacked button and file selection dialog

Load unpacked button and file selection dialog

Step 5Verify Installation

After loading the extension, verify it was installed correctly:

What to look for:

  • The extension should appear in your extensions list
  • It should show as Enabled
  • You may see the extension icon in your Chrome toolbar
  • Check for any error messages (red text) that might indicate issues
Successfully installed extension in the extensions list

Successfully installed extension in the extensions list

Success! Your custom extension is now installed and ready to use.

Troubleshooting Common Issues

“Manifest file is missing or unreadable”

Make sure you selected the correct folder that contains the manifest.json file. The manifest file should be in the root of the extension folder, not in a subfolder.

Extension appears but doesn't work

Check the extension details for any error messages. You may need to reload the extension by clicking the refresh icon next to it, or contact the extension developer for support.

“Load unpacked” button is not visible

Make sure Developer mode is enabled (toggle should be blue/green). If you still don't see it, try refreshing the extensions page.

Extension is blocked by company policy

Some organizations restrict extension installation. Contact your IT administrator if you cannot enable Developer mode or install extensions.

Important Notes

Security Warning

Only install extensions from trusted sources. Custom extensions can access your browsing data and potentially compromise your security.

Updating Extensions

Custom extensions don't auto-update like Chrome Web Store extensions. To update, you'll need to replace the extension files and reload the extension in Chrome.

Removing Extensions

To remove a custom extension, go to chrome://extensions/, find your extension, and click the “Remove” button.

Need Help?

If you encounter any issues during installation, our support team is here to help.

Contact Support