Bookmarklet to append a string to the end of a URL

window.location.href

window.location.href
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Bookmarklet to append a string to the end of the URL.

1. Create bookmark.

2. Edit bookmark URL(Chrome) / Location(Firefox) to include this code: javascript:window.location.href=window.location.href+'REPLACETHIS';

3. Now make use of that bookmarklet.

Code: javascript:window.location.href=window.location.href+'REPLACETHIS';

Are you sure / did you test this? I'm pretty sure it will change to example.com/hello?foo=1&KEY=VALUE. That's the documented behavior, too: https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/set#examples
oops... you're absolutely right it does work... I missed that you were initializing with the location.search). My apologies!

But it is still half as long :)

How do I make a bookmarklet which adds "about:reader?url=" to the beginning of the URL?

How do I make a bookmarklet which adds "about:reader?url=" to the beginning of the URL?

Honestly, I don't think you can from a bookmarklet in modern Chrome due to the security settings. If you try to it redirects you to an about:block page.

Even from the DevTools console if you try the following it's blocked. I certainly don't want to say that it can't be done by somehow loosening security settings, via some JS glitch, or via an extension, but in terms of a traditional bookmarklet that will work for most people, I don't think it's possible. It isn't allowed in modern Firefox either.

location.href = 'about:reader?url=https://www.google.com'