When it comes to finding legal Open Access copies, no single API stands out. Each API has its own benefits and downsides. I’ve selected unpaywall.org as the default API, partially because I got started with it and partially, since I personally feel it does a marvelous job.
A bit later I added Core Discovery API and it was a non optional add on, but when I started the work on adding Open Access Button API, it quickly turned into an example of the law of diminishing returns.
Speed Matters & Why Defaults Are What They Are
Both unpaywall.org and core.ac.uk are very speedy and thus using both doesn’t cause much harm.
Open Access Button API seems to do a lot more things in the background and can take a few seconds to return. It felt like asking it a question that both unpaywall.org and core.ac.uk API have already responded to negatively, was really harsh on their API. Remember I don’t pay them, neither do you, so asking them a lot of questions to which you already believe the answer to be “no” seems unfair.
Thus the default is for unpaywall.org and core.ac.uk APIs to be active!
So what should you do?
How about you start off by activating the third option “Offer to take me Open Access Button to make an article request”. What this will do is add a blue button in the top right, whenever unpaywall.org and core.ac.uk responded negatively enabling you to quickly make a request. Simply click it. If there is an Open Access version, you will be redirected to the full-text and if there is not, you get to ask the authors for them to make it open for all.
As a matter of fact, I was really close to making that my default configuration 😉
If you need the extra umph of having all three APIs at your disposal, feel free to enable the second option and consider disabling it, should you no longer need it. Be kind to all those awesome API providers, we don’t want to hurt them!