When comparing Sketch vs Affinity Designer, the Slant community recommends Sketch for most people. In the question“What are the best mockup and wireframing tools for websites?” Sketch is ranked 4th while Affinity Designer is ranked 9th. The most important reason people chose Sketch is:
Sketch is hugely popular among designers so there are a lot of well maintained community [resources](http://www.sketchapp.com/community/) for everything from iPhone frames to iOS/Android UI elements & icons.
Ranked in these QuestionsQuestion Ranking
Pro Active community with a lot of resources
Sketch is hugely popular among designers so there are a lot of well maintained community resources for everything from iPhone frames to iOS/Android UI elements & icons.
Pro "Artboards" are great for working on multiple views simultaneously
Artboards let you easily work on multiple views side by side. Great for having a separate artboard on each page for the various responsive sizes.
Pro Vector based yet pixel aware
You can rescale assets without quality loss, easily export x2 assets for retina designs and design high quality icons & artwork. Being pixel aware lets you set a grid and snap objects to it as well as round to the nearest pixel edge to clean up your layers.
Pro Designed specifically for web and mobile UI design & workflows
Sketch is essentially a version of Photoshop built from the ground up to suit the workflow of web designers.
Pro Makes it easy to export assets
Sketch has a built in exporter that supports PDF, JPG and PNG.
Pro Clean UI
Reactive panels keep the UI for Sketch clean from the sort of clutter the panel system in Photoshop suffers from. The panels in Sketch change based on the object in question, saving you from having to have a multiple separate panels.
Pro Built-in grid system
You can set the square grid to whatever dimensions you like as well as set thicker lines every x blocks. You can also configure the color of the lines to make them as obvious or subtle as you wish and toggle the grid with a keyboard shortcut (crtl+g).
Pro Symbols and shared styles
Sketch lets you re-use the same design in multiple places, with changes synced throughout the various places it is used. You can also create text styles to sync typography changes.
Pro "Mirror" makes it really easy to test designs on multiple devices
Mirror lets you connect your iPhone to sketch and see how your current artboard looks on mobile. It's really useful as you can live check changes which lets you rapidly iterate mobile design.
Pro Easily align layers with smart guides
Holding down alt will show the smart guides that show the distances between any layer you hover over to nearby layers or the edges of the artboard. Very useful for checking your spacing or aligning layers.
Pro One-time purchase
Rather than a monthly subscription based model, Affinity Designer instead has a one-time fee ($49.99).
Pro Intuitive user interface
The user interface of many graphic editing software programs can often be discouraging for beginners. Affinity Designer, however, has a very well laid out and intuitive user interface with a small learning curve.
Pro Powerful artistic tools
Extensively tweakable brush types, color options...
Pro Extended slicing and export possibilities
An object can easily be transformed into a slice that can then be exported in various sizes end formats in 1 go. E.g. Export slice A as PNG 1x, 2x and 3x AND GIF 1x AND SVG.
Pro Powerful symbol managemment
Symbols can get individual property changes (color, shape, layer effects, fonts text...) while the other properties stay linked with the base symbol.
Pro SVG Support
In the era of "retina" displays, 4k UHD, 5k, and even 8k, Scalar Vector Graphics - independent vector images that can scale to any resolution without any display quality loss - are more important now than ever.
And this tool is quite capable of rendering true SVG output suitable for consumption at any display resolution (not a big bunch of rasterized bits in the document, actual paths, points, etc.).
Pro Cross platform
Available on both Windows and MacOS
Pro Focused vector graphics tool
Unlike some design tools, Affinity Designer isn't trying to be all things to all people. It's focused on its main area of expertise: vector graphics. That's not to say you can't use a raster image (think a photo in *.jpeg format for example), but it's not built to do much with that other than using it somewhere amidst the layers and that's about it.
Pro Sketch Alternative (Great for Mixed OS Teams)
For those working in mixed environments that aren't 100% MacOS, you'll find devoting yourself to Sketch.app brings with it...pain. If this fits the bill for what you need feature-wise and you're in a mixed OS environment, it's a very capable replacement for Sketch.app. Note that it doesn't have all the same features, but then again it doesn't need all the same features. Short of organization differences inside the document you're working on, there shouldn't be anything you can't do with Affinity Designer that you could have with Sketch.
Pro Integrates well with Affinity Photo
These are companion apps & switching between them is built in - Photo is a very powerful raster tool with a feature set close/better to Photoshop, it will also use some Photoshop plugins. This allows you to add-on powerful raster capabilities if you want them - put doesn't force you to.
Pro Excellent Photoshop/Illustrator import & export
Best I have seen in a non Adobe app, you can use most of the Photoshop mock-ups and templates easily. Opens most Adobe files to a level to be able to effectively use the content. Allows cross team collaboration across tool-chains.
The new version 1.5 has a very powerful feature set such as support for symbols and asset windows, as well as constraints controls and improved export options. This all adds up to an interesting alternative to Adobe Illustrator.
Con No Linux version
Sketch is currently only available on Mac, which can make it hard to collaborate if you have teammates using Linux.
Con License based payment model
Sketch has recently decided to cease development of major version (2.0, 3.0, 4.0) with free updates in between, and has switched to a license based subscription model. A yearly license costs $99 and includes the latest version of the Sketch software, plus a year of free updates. After this license expires, you can renew for another year of updates - or continue to use the current software without updates.
Con No Windows support
Con Very feeble raster tools
You have to go elsewhere if you want something more complex than basic vector masking of raster images.
Con Buggy releases and lack of quality assurance
The fast rate of change means new releases often break files and cause havoc. Duplicate symbols are really bad in the latest releases so you have to keep updating.
Con Limited compatibility with Photoshop and Illustrator
Although it is possible to export certain Adobe file types in Sketch, compatibility is mostly hit and miss. For example, some elements seem a little offset in Adobe products.
Con No plug-in architecture, so can't be tailored to specific purposes
Some applications (e.g. Sketch) have an open plug-in framework, by which the software can be extended by independent/third-party developers according to popular trends.
Con Treats all objects as filled
You can't select objects on the canvas by clicking on them, if they're surrounded by another object (like a rectangle or a frame). Designer treats all objects as filled, so if you've drawn a frame or outline or an object with a hole in it, you can't select objects within that hole directly. You have to laboriously iterate through all objects in a list until you get to the one you want. This is an extremely common situation, which cripples the entire product. Very surprising and unfortunate defect.