This one is a bit difficult… All gallery plugins claim they have the fastest loading gallery, and all will feed you with tests to support their claim.
Without going into a comparison war, let’s check what makes a good choice of a gallery plugin.
Here are a couple of conditions:
- Premium/paid is a priority (more stable)
- No bloat, even if it means having less features and less control
- Extensible when needed
- Uses the native WordPress gallery system
- Has steady updates
- And no hacking history
One of the plugins fitting the above is Meow Gallery.
The following page has a 16 pictures gallery (ranging from 1 to 2MB each). And yet, the whole page loads in 180ms :)
Yes, there are a couple of tricks to get that loading time, but still, using Meow Gallery helped with that too.
Meow sits on top of the native WP gallery with minimal added code + a pretty good lazy loading system.
I picked Meow for its simplicity and performance and also for a couple of additional plugins part of the Meow Apps ecosystem (namely the Retina plugin and the Lightbox plugin).
Other galleries have similar features. But non has that many granular features enabling and a low scripts/style footprint. It gives you the minimum you need to get the job done.