Looking on the internet deeply has found these results:

by default is the most popular phrase on the web.

as default 17,240,000 results on the web	by default 160,300,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	In a number of cases, ITS systems will be integrated in vehicles by default. A judgment by default shall be enforceable. I clung to the hope Ben's fear of being alone would drive him back to me by default. So I guess by default, you win the best mover prize. You weren't around, so he's my son by default. Here you can choose which cryptographic message format to use by default with this identity. And by default, where he may be stashing Angela miller. Manchester was one of the first settlers and wound up becoming their leader by default.

as default

17,240,000 results on the web

by default

160,300,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

In a number of cases, ITS systems will be integrated in vehicles by default.
A judgment by default shall be enforceable.
I clung to the hope Ben's fear of being alone would drive him back to me by default.
So I guess by default, you win the best mover prize.
You weren't around, so he's my son by default.
Here you can choose which cryptographic message format to use by default with this identity.
And by default, where he may be stashing Angela miller.
Manchester was one of the first settlers and wound up becoming their leader by default.