Custom Site JS icon

Custom Site JS

by David Hicken · Developer Tools
Manifest V3 Free
View in Chrome Web Store Data as of 16 Oct 2026

Run your own (per url or domain) custom JavaScript on sites.

Users
124
+9 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
1
0 in 30 days
Store rank
#78K
#65K among extensions
Version
1.0.2
updated 26 Oct 2024

Users

monthly, 3 years
3128253Aug 2023Apr 2025Oct 2026
Latest, 16 Oct 2026: 124 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years
001Aug 2023Apr 2025Oct 2026
Latest, 16 Oct 2026: 1 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Custom Site JS

Have you ever wished you could customize a website to your personal preferences every time you visited it? Ever heard of a bookmarklet? Bookmarklets run JavaScript on a page for you when you click on the bookmark. But how inconvenient to have to click a bookmark every time you visit a site? What if you could have your JavaScript simply run on the site as the page loads with no extra effort from you? That's what this extension is about. Custom Site JS allows you to Add, Edit, or Delete snippets of custom JavaScript, that will automatically be run on a page for you based on a URL you provide. You can create as many as you like. The only limit is a maximum of 5 megabytes as the scripts are stored in your local storage. Everything is stored and run locally. This extension will never make any kind of external web request, network requests, or in short send any of your information anywhere. The only way it will pass any information outside of your local environment is if you create a snippet of JavaScript that explicitly sends information somewhere.

Growth

WindowUsersChangeRatingsRating
7 days+1+0.8%00.00
30 days+9+7.8%00.00
6 months+2+1.6%00.00
1 year+10+8.8%00.00

Chrome Web Store search rankings

Where Custom Site JS appears when people search the store, with the 30 day change
Search phrasePosition30 days
site#23+11

Version history

2 versions recorded
1.0.226 Oct 2024
1.0.128 Oct 2019

Details

Category
Developer Tools
First seen
28 Oct 2019
Size
95 KB
Languages
en-US
Pricing
Free
Extension ID
pclbdoihplpfbkmebiaojnhfbgdgkcol

Permissions and risk

Moderate riskimpact 3, likelihood 1
Permissions
webNavigationstoragetabs

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