Original credit to Ben Kahan. https://chrome.google.com/webstore/detail/appnexus-creative-inserti/ailiopjkbojmmdflhbcedndlomhmhkbk he had the idea
Sadly his extension is outdated since appnexus discontinued the api he was using. So I updated it using the AST API. Also made it always secure and migrated the code to ES6.
This Chrome extension enables dynamic insertion of creative Ads in any HTML element in any page. This can be used for proofs or for debugging your creative in a live environment.
How to use:
Load the site on which you wish to preview the creative
Click the AppNexus Creative Insertion Tool icon to the right of the URL bar
Move the mouse cursor over the layer you want to use as placeholder for the creative. It should show a message with the text “SELECT”.
Click on it, a input prompt should appear.
Paste the AppNexus Creative ID and press Enter
Enjoy the view.