Bookmarklet vs browser extension: which should you use?

Both put a button in your browser that does something to the page you are on. The difference is what happens when you are not pressing it.

An extension is installed software. It sits in the browser, can be granted permission to read and modify every page you visit, and updates itself silently. A bookmarklet is a bookmark whose address happens to be a line of JavaScript. It has no presence, no background process and no permissions. It exists as text until you click it.

The permissions argument, plainly

The Chrome prompt "read and change all your data on all websites" is not marketing caution. It means the extension can see everything rendered in your tabs: your webmail, your bank statement, the internal wiki at work. Most extensions asking for it are honest and simply need it to do their job. The problem is that the permission survives the publisher.

A bookmarklet cannot do that. The code is stored in your own bookmark, in plain text, and it only executes on the page you are looking at when you click it. If you want to know what it does, you can read it in ten seconds.

A real bookmarklet

Here is the entire PrintxPDF bookmarklet. It takes the address of the page you are on, URL-encodes it, and opens the cleaner with that page loaded.

javascript:(function(){
  window.open(
    'https://printxpdf.com/print?url=' + encodeURIComponent(location.href)
  );
})()

That is all of it. No network calls of its own, no storage, no listeners left behind. When you paste it into a bookmark it must be on one line, which is how the ready-made button supplies it.

How to install a bookmarklet

1. Show your bookmarks barCtrl+Shift+B on Windows and Linux, Cmd+Shift+B on macOS. In Safari it is View then Show Favourites Bar.
2. Drag the ready-made buttonGo to the extensions page and drag the ⚡ button onto the bar. That is the whole install on desktop.
3. Or create it by handRight-click the bookmarks bar, choose Add page, put anything in the Name field, and paste the one-line JavaScript into the URL field. Chrome accepts javascript: here even though it strips it from the address bar.
4. In FirefoxRight-click the bar, choose Add Bookmark, and paste the code into the URL field. Firefox may warn about a JavaScript bookmark; that warning is expected.
5. On iPhone or iPadYou cannot drag. Bookmark any page, then edit that bookmark and replace its address with the code. Open Bookmarks on any page and tap it to run. Easier still: create it on your Mac and let iCloud sync it across.
6. Test itOpen a normal article and click it. A new tab should open with the cleaner loaded and the article already fetched.

When an extension is genuinely the right answer

• You need it to act before the page renders, as ad blockers and script blockers must.
• You need a keyboard shortcut or a toolbar icon with a state, such as a counter or a toggle.
• You need it to run on every page automatically without a click.
• You need persistent storage, sync of its own settings, or a background process.
• The site uses a strict Content-Security-Policy that stops bookmarklets from running. This is uncommon, and the workaround is to open the tool directly and paste the URL.

Reformatting a page for printing needs none of those, which is why a bookmarklet is the honest recommendation here. To be explicit: the extension listings on this site are a design demo. Nothing is published in the Chrome Web Store, on addons.mozilla.org or in the App Store, and the install buttons do nothing. The bookmarklet is the working option today.

A third option people forget

You do not need a button at all. Pasting a URL into the web page printer takes about five seconds and installs nothing, which is the right choice on a borrowed or managed machine. Site owners who want their readers to have a print button can use the website button instead, so no visitor has to install anything. The browser-specific routes are in Chrome, Firefox and Safari.

Frequently asked questions