Custom JavaScript for websites

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This extension is no longer available in the official store. Delisted on 2025-09-15.

How to install an extension Open in Chrome Web Store

CRX ID

poakhlngfciodnhlhhgnaaelnpjljija

Status

Minor Policy Violation
Removed Long Ago
No Privacy Policy

Description from extension meta

Run custom JavaScript on any website.

Image from store

Description from store

Use this tool to inject custom javascript in any website.

Your scripts are kept in the local storage and applied across domain URLs.

You can use jQuery 1.11.0 or 2.1.0 or your own external scripts

Usage:
- site debugging (wrong list sort, etc.)
- hiding annoyng popups and Ads
- anything you can think of :)

New features:
- Ace Editor (formating, highlight, undo/redo by hotkeys)
- Draft auto save (so doesn't matter when you close the window without saving)
- Hosts (websites) switch (you can browse customjs of other websites)
- Include external script (eq. Underscore.js is cool)
- Launch script on the page embedded by iframe

Change log:
- 2.1.3 - Fixed Cyrillic problem in source
- 2.1.40 - Fixed a problem with the installation

Thanks to:
Ace - http://ace.c9.io/
Pure - http://purecss.io/

Latest reviews

Amanda Frazier 2021-04-08: ES6 IIEFs won't work, and I can't seem to access any DOM elements on the screen. Not sure what the point of this is.
robert cannot 2021-03-10: You can only set up on the main link ( example.com ) You can not set this link ( example.com/page )
A A 2021-02-27: A great idea, but its *constantly* deleting my saved javascript for websites, which means if I'm not backing up the files somewhere literally every time I make a change, I'm going to have to rewrite the code.
דניאל ל 2021-02-12: There is a problem bypassing the 30 seconds countdown timer in this website: https://sdarot.tv/watch/3284-%D7%91%D7%99%D7%AA-%D7%94%D7%A0%D7%99%D7%99%D7%A8-money-heist/season/1/episode/4
Andrey Izman 2020-12-01: Does not save multi-line template strings and even regular multi-line strings split by ' + '. Just waste of my time. Don't use it
Erik de Boer 2020-11-29: Great extension, it does exactly what it has to do perfectly.
Suleiman Boutzamat 2020-11-15: After a refresh, my code still runs but it cannot be seen in the editor!
Roman Karagodin 2020-10-27: I used this extension until recently with my custom script for autofill, and it works well. But I switched to Custom JavaScript for Websites 2, because CJS1 has several very unpleasant bugs (e.g., in CJS scripts are often ineditable, because their text in editor mystically disappears, except for the 1st line; also, CJS editor is almost impossible to be dealt with from mobile devices). Unlike the this extension, CJS2 is totally free of these issues and works perfectly.
Mike L. 2020-10-02: code gets cut off after saving / stops running.
Andrew Surdu 2020-09-23: Stupid extension. I press "Save", the page is reloaded automatically and the code is gone. Totally disappointed. Also the tab looses the focus, the code is gone as well.
Zellmer 2020-08-24: meine Scripte werden nicht gespeichert, also auch nicht ausgeführt
fires3as0n 2020-04-14: I put 20 lines of code, page reloads, I open editor, there is only first line of code there
Anbarasan 2020-04-01: I love it
Haneol 2020-03-30: I will share my script. This is for youtube and when video is clicked, that will be opened in another specific tab. This will be useful when watching video with second screen and searching with the other. If anyone who can make it better, please let me know... $(document).on("click", "a", function(e){ let href = $(this).attr("href") if (href.startsWith("/watch?v=")) { window.open("https://www.youtube.com" + href, "youtube") setTimeout(function(){ window.history.back() }, 500) } })
Jeremy Wu 2020-03-23: hmmm, It would be better if you support controlling script position in HTML https://developer.chrome.com/extensions/content_scripts#run_time
Andrew A 7698 2020-01-15: Not work, but in console my script work
Alex P 2019-10-15: Doesn't work. Waist of time.
Paul Vasile 2019-10-14: Doesn't work
Vasyl Butov 2019-10-08: Does exactly what it supposed to, BUT if you clear site data, extension's data clears as well. I'd like ether an option to keep script even after clearing site data or some preset templates to quickly apply changes. P.S.: absolutely love this extension, but 2 starts just for devs to notice this.
Motaz Ibrahim 2019-09-27: There is no explanation on how to open the editor and use it I click on it and then nothing
Adrian Boisclair 2019-09-08: This is a great extension. Seems to have a few minor issues, ie sometimes the javascript doesn't load into the editor (the dropdown text-box containing the JS) but other than that it works nicely. I'm curious though.. One thing that strikes me as a little bit intrusive on an individuals privacy is that your extension is able to read all of our browsing history. Is this 100% necessary? If you had an anonymous version of it I bet it would be huge in popularity.
Adam Yeh 2019-09-07: This is perfect app and i love it so much!
K F 2019-09-06: Za każdym razem czasu usuwa napisane skrypty.[PL] Every time deletes prepared scripts .[ENG]
Jake Crump 2019-08-15: hey google. Delete all other js-injection plugins because this one works and the others are trash. kthxb
Will Ashley 2019-08-11: Has a pretty egregious bug. When you paste in your JS to the text area, hit save, reload the page, then click the extension again, only the first line of the pasted code is prefilled in the editor, but it seems like the extension does indeed save the state because the snippet still runs. Seems like a very strange bug. It should always show the full snippet upon reload each time, otherwise it is not worth the time as tweaking your snippet as your needs change will be untenable.
Evan Matariel 2019-07-16: Funciona de maravilla
xj x 2019-07-11: only one line of source loaded
M i r a c H 2019-07-03: Works perfect, dont forget to block your .js file on console!
Sergey Nagorets 2019-04-03: Works perfectly, but having possibility to sync would be great!
Jean Marc 2019-03-30: It works but I can't see the code after few days, only the first line of the code is visible, don't want to write everything all over again.
Ethan M 2019-02-13: No more clicking the same button across 30 tabs. I just find the button (via XPath -- see below), and let this wonderful CJS extension rip! var x = document.evaluate('//path/to/some/button', document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE); x.snapshotItem(0).click(); I am - however -- having better luck with this apparently cloned version of CJS: https://chrome.google.com/webstore/detail/custom-javascript-for-web/ddbjnfjiigjmcpcpkmhogomapikjbjdk/related?hl=en.
David Brewitz 2019-01-30: Been using it for a couple years and it does what it says.Works great for adding your custom js.
Jukka Hautakorpi 2019-01-10: Scripts dissapear every other month or so without a trace. Not so good.
Michael Ivanov 2018-12-09: Exactly what I was looking for.
Erik Brickarp 2018-11-27: Performs exactly what it says and performs it well!
Joseph Salerno 2018-10-23: Simple, to the point and no annoying extra feature or limitation. Just perfect.
eslam alshbah 2018-08-29: I like it so much
Ron Klein 2018-07-19: Great just missing the ability to import & export the JS code (for backup or for moving to another computer) Also, there is a bug that it's not possible to inject more then 2 external files (the second line is wrongly concatenated with the third line creating wrong url to inject)
Nicolas Mokris 2018-05-27: Custom code suddenly disappeared.
Marat Dospolov 2018-05-11: Man it's awesome!!! Thank you!!!
Merbin Joe 2018-04-24: Nice, very helpful

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