Having a backend page that has about 1000 select boxes that need to be initialized by a searchable/autocomplete selectbox. I checked the loading times of the page and the time of the initializitation of the select box. I measured it first by hand and later on by Safari web console.
- Has no ajax support, if you want to do this, you can combine it with select2.
Select 2 performance
Selectize.js: about 19s. Console crashes after 29s. So, I exclude further results.
Bselect: more than 40s, I got bored counting, so I exclude further results.
And the winner is … Chosen
It is initializes as fastest, being about 1,5x as fast as Select2. Although, Select2 has lot more functionalities and is better maintained. When you only need simple searchable select boxes and mind about performance, Chosen is the best choice. Note that it is only one simple configuration, it might be that in other configurations Select2 is faster than Chosen.