I've been using GeoGebra for years. I have tried Desmos twice but couldn't immediately spot the differences. What are the benefits of Desmos over GeoGebra?
Desmos has a far smoother UI. Geogebra will often convert equations into its own format after clicking away from the equation editor, and if you mistyped or want to change the structure you must erase and re-type the whole thing—for example, typing f(x) will convert the equation into its own format where you can't edit parameters or the function name. Desmos leaves your input as text, allowing you to change input at the character level. From my high school experience where both were used frequently, a lot of frustration was expressed with Geogebra where missing a parenthesis forced you to re-type the entire equation since it often assumed the bulk of your equation was a parameter, and there was no way to correct it.
> frustration was expressed with Geogebra where missing a parenthesis forced you to re-type the entire equation since it often assumed the bulk of your equation was a parameter, and there was no way to correct it.
I believe this may simply be a case of not knowing Geogebra well, or it's simply caused by differences in taste/being accustomed to a single user interface. In my experience, Geogebra offers the ability to edit the source of any object after selecting its settings. So it was just two clicks away.
This is Geogebra the Electron app, though, I think there's also a Web app and I think there was also a Java app some time before.
I just want to chime in on Geogebra. I used it (was more or less forced to) when teaching math in high school for about 12 years. It is great for guided exploration, but it is very buggy. I am confident many students must have lost points in their math exams because of some of those bugs.