What are the best rapid prototyping tools for product experiments?

by Michelle Chu
June 26, 2015

Product teams that adopt and apply lean methodologies are often challenged to find the best way to prototype their product ideas. Understanding product market fit is one thing, but having the ability to rapidly design and test prototypes is another. In addition, creating prototypes for the specific purpose of generating user feedback requires a different mindset than prototypes also built for internal stakeholders (i.e. getting buy-in from leadership and sending specs for engineering).

A wide variety of tools are available that address the diverse and growing needs of digital prototyping. While it’s great to have so many software solutions available, there’s no silver bullet. The “best” tools to use depend entirely on your organizational structure and the immediate purpose for the prototype. Not only that, but this purpose will change throughout the product lifecycle.

While some prototyping tools require the expertise of designers and developers, others are just as powerful in the hands of a product manager. It’s often efficient for the product manager to create simpler prototypes earlier in the process, in order to independently test high level hypotheses, and then move on to more advanced tools in collaboration with design and engineering, when it makes sense to invest in those areas.

Ask yourself these questions before choosing the right set of tools for your needs:

  • What do I want to learn from my next prototype test? The earlier you are in the experimentation process, the more vague the value propositions you’ll be testing. You’ll want prototypes that clarify and emphasize initial hypotheses to users, rather than focusing on the unrelated assumptions of user experience flows and other areas. Later in the process, this may change.
  • What are my constraints? Consider the amount of time and resources it makes sense to invest at the current stage of testing. Is there enough promise and momentum that it’s worthwhile to involve designers and engineers in the development of a prototype?
  • What are my requirements? Factor into the design process whether or not the value propositions with which you are experimenting require a mobile app prototype. Or maybe you’ll need a website that simulates advanced interactions.

Below are my recommendations for prototyping tools, based on the questions above. This is not a detailed, comprehensive review of all existing prototyping tools, nor is this a tutorial. Instead, it’s a reference that outlines the best tools to use at different points in the product lifecycle, given the capabilities and constraints of a product team.

Full-stack setup to get going quickly

At Alpha, we rely on the following three tools with clients because of their ease-of-use, built-in template libraries, and general capability to efficiently test high-level and granular hypotheses across device types.

Keynote: Keynote’s presentation software works surprisingly well as a prototyping tool for non-designers to create low simulations of value. With an impressive library of templates available at Keynotopia, you can quickly build prototypes from scratch with few other design assets required. Without draining additional resources, Keynote can replace pen and paper for rapid testing of high-level value propositions.

Sketch: Sketch is quickly replacing Photoshop as the go-to-program for designing user interfaces, due to its ease of use, free templates, and multiple screen resolutions. With Sketch you can build web, mobile and tablet experiences by simply dropping available UI elements onto Sketch artboards. While there are no animations or interactions available, many other prototyping programs integrate nicely with Sketch files, including InVision, Marvel, UXPin and Framer. In addition, it’s super easy to export graphic for use in all other prototyping programs that do offer animations and UI behaviors. If you are new to design programs, this is the one to learn.

InVision: InVision is becoming a tool of choice for product teams, and adds limited user interactions to graphic assets, for testing in a simulated environment (you can run prototypes on mobile directly). Interactions available include transitions, hover states, scrolling, and anchor links, and new features are constantly being added that make it easier for product teams to collect both qualitative and quantitative data from experiments run. Note that this tool requires existing design assets to be built first (you cannot build screens from scratch), so you’d need to use it with another tool, such as Sketch.

One organization, one tool

Alternatively you may find for any number of reasons that your organization would best be served by a single prototyping solution, even if that means sacrificing speed and ease-of-use. Here are a few to consider:

Axure: Axure is one of the oldest and most prominent prototyping tools for enterprise. Because of its large user base, it has an active online community and numerous forums for support. It offers advanced desktop animations, as well as other features such as versioning control, responsiveness to numerous screen resolutions, and HTML output for browser viewing (though you will likely need to scrap this code for real production). Note that this tool is not meant for building a polished, visual design; it’s meant for teams to build interactivity using basic graphics. Also, while it does have mobile capability, it lacks more complex mobile interactions that you may want for building an app prototype.

JustinMind: JustinMind is the shinier, newer version of Axure, and unlike Axure, does play well with existing design assets. It also comes with design templates for graphics designed within the tool itself, and was designed with more complex mobile interactions in mind, as well as the ability to preview on the device itself. However, because it’s a newer kid on the block, there are fewer people using it, and less documentation as such.

UXpin: UXpin also comes with a large library of modern UI elements and templates, and has complex interaction capabilities for desktop and mobile. It is similar to JustinMind, with plugins available for Sketch and Photoshop, allowing you to edit in these programs and have changes pulled in automatically. Lastly, you can record users’ face and desktop during user testing, view it in real-time, and get comments from users while they’re interacting. Note that while it has an impressive amount of features, performance in the tool can be frustrating or buggy, and like JustinMind, fewer organizations have adopted it.

Technically-savvy with the ability to test more advanced interactions

If you have a technical background or engineering resources dedicated to prototype testing, there are some more advanced interactions you can design to generate user feedback on prototypes that more reliably reflect a finished solution.

Framer.JS: If you have experience with JavaScript, Framer is an incredibly powerful prototyping tool for both desktop and mobile. It has robust animation and microinteraction capabilities and is compatible with web, mobile and tablet. Framer also plays well with existing assets in Sketch or Photoshop.


To escape the bloat of software solutions that accommodate many screen resolutions, it may be worthwhile to check out services that focus on mobile. I recommend two below, depending on your desired library of interactions.

Flinto: Flinto has similar capabilities to InVision, except it’s a little easier to fine-tune user flows, and some prefer its screen linkage approach over InVision. Low start up time required, but it’s not capable of creating complex interactions.

Pixate: Pixate is capable of producing robust microinteractions for both iOS and Android, and is becoming the favorite tool for app creators, based on its mobile focused feature set.

Keeping it simple and low-tech

Although professionally-designed prototypes can be effective for understanding user behavior in response to value propositions, it’s common for team members to become too defensive of prototypes and create barriers to revisions and iteration. We sometimes recommend product teams begin with paper prototypes to eliminate this scenario, as it’s much easier to discard a sheet of paper.

Often, you can even learn almost as much from simpler, less ‘snazzy’ prototypes. They force users to focus on and respond to the value propositions instead of getting hung up on the user experience. In fact, there’s a lot to learn if users can’t get over the lack of aestheticism – it tells you that users may not desperately have the need you hypothesized.

Pen and paper: Pen and paper enables product managers to communicate their ideas to designers and users with ease. It’s well suited when you’re in the earlier stages of prototyping. You can use this basic tool to scope out the core functionality and value of the product.

Balsamiq: Only slightly more exhaustive than pen and paper is Balsamiq, a tool that virtually anyone can use to build wireframes and basic mockups. Although lacking just about all interactions, you can build clickable PDFs to iterate early in the product lifecycle.


While there are many prototyping tools on the market, most have their own unique advantage that can make them useful during some phase of the product lifecycle. It’s important to first consider your business objectives and practices before selecting the right tools to use. Picking technologies first can severely handicap your prototyping process, short-circuiting your ability to optimize and find an adaptable solution.

Nearly all prototyping tools come with a free trial, so you can download and see which tool works best for your needs. If you’re looking for perspectives on a wider spectrum of prototyping tools, I recommend checking out Emily Schwartzman’s guide, Ian Schoen’s prototype graph, or this great discussion on Quora.

Michelle Chu