Wolfram alpha does provide step by step solutions, at least for integrals, but I think it's paid. Although there might be a way to get around that
If you have an Android phone the app is like 9.99$ one-time payment (idk about apple)
I'm not sure, I remember I could do it, but that was years ago, and I don't remember exactly how. Anyway I think you can try the step by step solutions for free a couple of times
I don't have the link, but first result for "integral calculator" is a comprehensive step by step solver
how's this one for you? https://mathforyou.net/en/online/calculus/ode/
awesome, that shit is its own reward for me lol, glad to be of service
https://tutorial.math.lamar.edu/
edit - didn't see that you're looking for a solver, this is more of a textbook with a lot of very clearly solved sample problems. Still a great resource tho
One of the best I know of for integrals is https://www.integral-calculator.com/
idk how difficult you're talking when you say "difficult integrals and differential equations" tho
