When comparing Keynote vs Moqups, the Slant community recommends Moqups for most people. In the question“What are the best mockup and wireframing tools for websites?” Moqups is ranked 1st while Keynote is ranked 24th. The most important reason people chose Moqups is:
Moqups is built in HTML5 and standard Javascript, so it doesn't require any plugins to use. The application is very fast to use.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Imports nearly every type of asset
Can import all kinds of assets (images, videos, PDFs, sounds) into mockup without hassle.
Pro Animations and transitions
Keynote currently is one of the very few tools that supports animation of elements and transition of views without programming.
Pro Text Styles makes it easy to create typography systems
Pro Smart Snaps
Keynote has alignment grids (aka snap to grid feature) that snaps to end, midpoints, baselines etc of objects and grids. They are super useful when you want to follow a structured layout for your wireframe.
Pro Fast and doesn't require any plugins
Moqups is built in HTML5 and standard Javascript, so it doesn't require any plugins to use. The application is very fast to use.
Pro Supports 960gs
As well as a standard snap-to-grid, Moqups supports the 960 gridsystem.
Pro Free tier
The Free Plan offers 2 active projects with at most 300 stencils each and 5 MB of storage. This plan does not include: Master Pages, Real Time Collaboration, Privacy Settings, Unlimited Revisions, Unlimited Project Archiving and Teams.
Pro Clean design and very intuitive
Pro Keyboard shortcuts
Moqups has an extensive list of keyboard shortcuts. Simply type some A-Z letters to search for components. F1 for an overlay help screen.