When comparing Sketch vs GRAVIT, the Slant community recommends GRAVIT for most people. In the question“What are the best high-fidelity website design tools?” GRAVIT is ranked 2nd while Sketch is ranked 3rd. The most important reason people chose GRAVIT is:
Gravit has a free version, but there is paid version with more features.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
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 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 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 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 "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 Makes it easy to export assets
Sketch has a built in exporter that supports PDF, JPG and PNG.
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 "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 Free
Gravit has a free version, but there is paid version with more features.
Pro Multi platform
Works on Windows, Mac and Linux.
Pro Actively developed
Pro Easy to export all assets
Gravit has a built in exporter to PDF, JPG, PNG and SVG.
Pro Clean and helpful UI
The panels in Gravit adjust to contain the information needed based on the type of element selected, preventing the clutter that Photoshop often experiences.
Pro Easy to design multiple pages
The ability to assign layers to specific pages, and view single or multiple pages at once makes it easy to design an entire website without getting lost in thousands of layers. Easy to view multiple pages at one time.
Pro Symbols and libraries
With Gravit you can re-use the same design for buttons, inputs, etc, in multiple places, with changes synced every where the element is used. It's also possible to set text to a shared style to sync text changes throughout the app.
Pro Able to open Sketch files
The ability to open Sketch files makes it easier for Linux/Windows users to collaborate with people who use Sketch, which is macOS specific.
Cons
Con No Windows support
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 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 Very feeble raster tools
You have to go elsewhere if you want something more complex than basic vector masking of raster images.
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 Paid version
Expensive paid version that has many features you can find in free or cheaper applications.
Con This does not appear to be a Web-design tool
Gravit appears to be a vector-art tool, and nothing more. Their homepage doesn't even mention Web design as far as I can see.
Con Changing rapidly
The fast rate of growth/change for Gravit can be a pro in that in means plenty of new features.
However, it also makes the product fairly unpredictable.
For example: In the past year, Gravit was open sourced, then closed sourced again.