How can I selectively disable paste blockers

As more and more websites add paste blocking code of one type or another to e-mail and password fields and more people use password managers, the two are increasingly coming into conflict.

While there are extensions such as Don't fuck with paste for Chrome or Disable clipboard manipulations and the dom.event.clipboardevents.enabled preference^† for FireFox, all of these suffer the problem that there are legitimate reasons why websites might want to hook into onpaste (such as Google docs rich text support or Facebook's link handling) so I don't want that functionality completely disabled.

^{† Go to about:config and search for dom.event.clipboardevents.enabled then double click to toggle.}

Another option is to hack every page you find with the offending code manually, but that is a lot of hassle and doesn't work in every case (such as with this page). One suggestion of how to do this can be found on Martin Brinkmann's Paste Passwords into blocked form fields on the Internet page.

Ideally I just want to be able to say "Re-enable paste on all fields on this page" either as a button or a context menu option for the page, so is there any way to do this?

The closest thing I have found is Derek Prior's Re-enabling Password Pasting on Annoying Web Forms but this uses the same method as the manual method, so fails to work with the specific page I was having problems with, and I have no idea how many other methods might be available.

Web forms which have this paste blocker feature may implement it declaratively by using the onpaste attribute for a text box or by binding an event through JavaScript or jQuery.

Contrary to what you stated, I was able to get Derek Prior's bookmarklet to work on Chrome (ver 39 on Windows) with pages that had the attributes (type="password" onPaste="return false") on the password text box

You can also try Chris Bailey's bookmarklet which breaks paste blockers implemented through JavaScript.

This is a bit of a hassle but another alternative is to disable JavaScript temporarily for that page which in turn will turn off the JavaScript paste blocker. For Chrome, the keyboard shortcut to open Dev Tools is F12, to reach the Settings panel is F1 & here you'll find the checkbox to Disable JavaScript in the General section.

For pages that use jquery (basically all webpages). You can paste the following javascript url into the address bar

javascript:void($('input').attr('onpaste', ''));