Pixlr: A great (and totally free) collage maker

A versatile online and free collage maker can be found on the image editing platform Pixlr.

I honestly don't know how it can get better than this one: First off, you can save transparent background PNG files that you can size up. The examples I have here are 2000 pixel wide PNG images, the one up top with a transparent background. Which is great because it will look good on any kind of post background color. The software is very easy to use. The only thing that I couldn't locate was how to decrease or increase the spaces between the pictures. One can do it manually, but there should also be an automatic value and that is missing unfortunately. In the one on the top I brought the pictures together myself, manually. And below is what the software did.

One of the other things that is also great about it is that it lets you resize the canvas so that you can create narrow collages that would be good as post or even header images or really long ones that might work nicely as a sidebar element.

And, people - it is totally free. They do have pro accounts with which I would imagine that one can do quite a bit more, of course. But what you can do with a free account is already quite remarkable. You can add effects, text (and you can upload your own fonts, btw), shapes, overlay boxes and even animations to these collages - in which case, when they are animated, they can be exported as video files or as animated GIFs. And then, to also add is that this not just a collage maker but an all round photo editing / design software with which you can do quite a few other things as well.

https://pixlr.com

And finally, below I just threw together a few things just to give you an idea: