“Decoding” 500,000 ads from the 2020 US election

Decoder was a project we ran for the 2020 US Presidential election.

It used the URL strings found in ads by Joe Biden and Donald Trump to understand their targeting and messaging strategies. Most advertisers use parameters in the links they want you to click in order to track the performance of their ads. Some might also use these parameters to customise the pages you click through to.

By reverse engineering the parameters in these URLs, we were able to unpick the ways in which over 500,000 Presidential campaign Facebook ads were targeted and optimised.

The project is no longer live, but we’ve archived the source code and database if you wish to download and re-create it.

If you have questions about it, or need help with anything to do with it, get in touch. If you’re inspired by the idea and are making your own version for an election near you, do reach out. It’s also quite likely we’ll do something like it again for the 2024 elections.