Both Axure and Sketch are tremendous tools for UX designers. Sketch is an amazing design tool and Axure is not only a good design tool, but a powerful prototyping tool as well.
As someone who uses Axure at my full-time job (purely as a UX designer, separate from visual design) and Sketch at my freelance job (UX/UI designer), I have a good understanding of both programs. I use both these programs on a day-to-day basis, and this is how I believe they compare in six important areas:
Sketch - It is much faster to learn, but part of that is due to it being a simpler tool.
Axure - Quite complex with all of its interactive design potential, making some aspects of it easier to learn for someone with a development background than someone with a design background.
Sketch – Wireframes can be as lo-fi or hi-fi as you want. You can do a lot of the same things you can do in a design program, such as Adobe Illustrator. This allows you to not only do the UX design of a product, but also the graphic design.
Axure – It is made for UX design and not visual design. To make a prototype hi-fi requires a lot more work and weird workarounds (for icons, effects, etc.) than Sketch does.
Sketch - Creating symbols and editing them within Sketch is much easier to understand and I think that Sketch automatically generating a symbols page on the same document is very helpful.
Axure - You can create a library with a different document to make your own symbols otherwise you’re forced to use their default library of predetermined symbols. You can change these symbol styles but, you can’t just create a new symbol like you can in Sketch.
Sketch – The base price is $99/year.
Axure – The base price is $29/month. This is $249 more than Sketch per year.
Axure - Allows you to create nearly any interactive ability you could think of a user dealing with on a website or mobile app. You can create sliding carousels, sorting and filtering abilities, scrollable interfaces, even (seemingly) fully interactive maps! This is amazing for giving the user the full experience and can help developers understand what you want something to do when it’s interacted with.
Sketch - Has links and hotspots that the user clicks to refresh to another page, and that’s pretty much it. I honestly don’t even use Sketch’s prototyping ability, but use InVision instead. InVision doesn’t do much more either.
Axure - These can be used for interactions, but can also be used when going over your design with stakeholders. Instead of going to a separate board with a different design option, I will make parts of a design into dynamic panels. Dynamic panels me to be able to switch between different options for segments of a page. Example: I make a button on a page into a dynamic panel and set it up so I can click through an option where the button is a different shape, different color, is just a text link, etc., all without leaving the page.
Sketch - Unfortunately it doesn’t have any ability similar to this.
Both Sketch and Axure are very powerful tools for designers. I think both these programs are very useful for UX designer, but it really comes down to what you want to get out of the experience you’re creating. I recommend everyone try both and decide for yourself, which one you prefer.