I specialize in creating websites on Weebly and Squarespace because they are two of the easiest do-it-yourself website platforms and offer many beautiful designs that look great automatically on computers and smartphones.
There are a few differences in the two platforms, but for the most part, they offer similar features and choices.
In some cases, Weebly is the better choice for me to recommend to clients, but in most cases, I recommend Squarespace to people who are new to website design and maintenance. The most compelling reason to choose Squarespace can be summed up in one short sentence: You can cancel your mistakes.
There have been many times when I was thankful for Squarespace's Cancel button and rued the lack of that button in Weebly. In Weebly, design changes you make on a page are put into effect immediately. If you decide you don't like something after you change it, you have to remember what the page looked like before you started changing it and then redesign the elements on the page to revert the page to its earlier design.
In Squarespace, you can move things around on the page and add and remove design elements as much as you like, trying out ideas. No changes are made permanent until you press the Save button. If you press Cancel, your changes are dismissed. When I've messed things up on a page beyond the point of repair, that Squarespace Cancel button has been a lifesaver.
We all make mistakes from time to time; the magic Cancel button gives me a safety net that I really appreciate when I'm working on a Squarespace website.