The ultimate mockup tool to design websites and mobile apps

Create highly interactive mockups with the Justinmind mockup tool

Enjoy creating highly interactive mobile and web mockups quickly and intuitively with our powerful mockup tool

Developing websites and mobile apps can be costly and time consuming. Doing it without using a mockup tool beforehand can cost you even more in the long run. So why complicate the procedure?

Creating a mockup shows developers what is expected of them and gives them a clear set of instructions to follow. It allows the user to try out your future product and provide important feedback on any changes that need to be made. Using a great mockup tool therefore makes sense for your website and mobile design projects.

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Justinmind mockup tool lets you create a website or mobile app mockup with various screens and interactions. It also lets you test them as they would be in real life, without a single line of code. You can choose from a wide range of free downloadable UI kits for many popular platforms, including iOS and Android, and you can benefit from a highly collaborative workflow.

Read on to discover how the Justinmind mockup tool can help you and your team design the next award-winning app or website!

Easily design highly interactive website mockups

Web interactions

Having an interactive website is vitally important. It allows users to navigate and find the information they’re most interested in, in addition to entering data. But these are just the basic features. Many websites have advanced interactions that capture the user’s attention, making the experience enjoyable and exciting.

If your website is going to be interactive, then it makes sense that your mockup version is too. Why? Because, while you can add as many cool interactions to your website as you like, they’re not always guaranteed to work for the user. On the other hand, adding them to your mockup, testing them out and getting feedback from users, stakeholders and product managers is far less risky.

That’s where the Justinmind mockup tool comes in. Designing your website mockups in Justinmind allows you to add these cool features without touching on any expensive coding. You can add just about any kind of interaction imaginable in a few simple steps.

Justinmind mockup tool - add interactions to your website mockups

Depending on the layout you plan on using for your website, our mockup tool allows you to add triggers for mouse interactions, keyboard interactions, gestures (for touch screens) and much more.

Let’s take mouse interactions as an example. There are several you can add such as:

  • On click
  • On mouse down
  • On mouse up
  • On double click
  • On right click
  • On mouse over

Let’s assume you choose to add the “on mouse over” trigger. You then have access to a whole plethora of actions including but not limited to:

  • Linking to other pages
  • Showing tooltips
  • Hiding elements
  • Changing the style / color of an element
  • Rotating an element
  • Adding a microinteraction to an element

So, whether the website you’re designing will have only basic breadcrumb navigation and scrolling, or dynamic graphical effects and parallax scrolling, adding interactions with our mockup tool will certainly help bring it all to life!

Condition your interactions

Build your web and mobile experience further by adding conditions to your interactions with our mockup tool. Conditions are what turn your design from a simple wireframe to an interactive mockup. You can use conditions to add conditional navigation, respond to various inputs from the user, load animations, validate screen flows and much more!


Use variables to store any input information in your mockup. Whether you want to store text, images or data, variables have you covered. Want a name or address that’s typed on the first screen of your mockup to appear on the next? Learn how to easily do this in a few steps in our mockup tool with our tutorial on variables.

Create variable that work across pages with the Justinmind mockup tool

Responsive mockups

If responsiveness is one of the most important features of web and app design, why should it be any different for mockups? Designing responsive mockups is also crucial if you’ve adopted the popular mobile-first design system.

We here, at Justinmind, recommend you to use a mobile-first design approach, as Google’s mobile-first indexing predominantly ranks mobile content first.

The mobile-first system, something which is easily achievable in our mockup tool, makes it easier to design from smaller to larger screens but also ensures you address the issue of responsiveness immediately.

Our mockup tool gives you the capability to design responsive, scalable mockups that can adapt to multiple screens.

The Justinmind mockup tool helps you create responsive mockups easily

Easily design liquid layouts that allow elements to adjust to various screen sizes, aspect ratios and orientations by defining liquid containers. You can also take full advantage of our auto-resize feature to automatically resize UI components, meaning you don’t have to make multiple changes, and our advanced pinning system that lets you fix objects in containers or entire screens. Combining the latter with an offset allows you to create engaging, responsive experiences.

Speed up design with templates and masters


Templates are a standard collection of UI elements and interactions that are easy to create in the Justinmind mockup tool. They are great for maintaining consistency throughout your mockup and implementing a clear design system, as they allow you to reuse your content, increasing your efficiency.

Justinmind mockup tool - create templates to use throughout your mockup

In our mockup tool, you can simply build elements up into templates that you can reuse throughout different pages, saving duplicated work and making sure your design stays consistent. Templates are also an effective method for getting client and stakeholder buy-in, as they tend to be more interested in a general overview of a mockup rather than each individual element.


You can use data masters in your mockup to reproduce content and functional areas across all screens. The beauty of masters is, not only can they be used throughout your mockup, they can also be placed anywhere on the screen and you can use as many as you like!

Use data masters with the Justinmind mockup tool


Our mockup tool makes it easy for you to test out your designs. In Justinmind, you can simulate your mockup in an instant. You can then click through to different screens, interact with various elements and even use text fields.

Justinmind mockup tool - simulate your mockups on your desktop

Test interactions

Want to test those interactions you added? Want to see how your mockup’s pages scroll or if the data masters work? Want to see how that button moves when clicked? Just click “Simulate” or hit F5 to test your mockup on your desktop to see it and interact with it as it would be if it were the finished version.

Test responsiveness

Simulation is also a great way of testing your mockup’s responsiveness. You’ll see that, during simulation, the features will automatically scale up or down depending on your screen resolution.

Responsive mockups developed with our mockup tool can be simulated on any device. Website mockups can be simulated on your desktop by clicking “Simulate” or by simply hitting F5.

Test layout, data masters and variables

Simulations are also great for testing out the efficiency of your template structure and the layout of the screens in your mockup. You can also test your data masters to see if the functions applied do the job they were designed for and that the variables you applied work on all pages.

Get the best website mockup tool in the market - download Justinmind for free today!
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Powerful mockup tool to design mobile apps

In the same way as websites, using the Justinmind mockup tool lets you quickly and easily design mobile apps complete with pages, gestures and interactions.

Mobile gestures

Creating a mockup is useful to avoid problems down the line. But why stop at elements, templates and pages? After all, you want to be able to test everything. Gestures add authenticity to your mockup and help free up screen space.

Justinmind mockup tool - add gestures to your mobile mockups

Our powerful mockup tool allows you to experiment with and incorporate any mobile gesture conceivable into your design to make your final app more intuitive to the user. Here are some examples of the most popular mobile interactions you can add in Justinmind:

  • Tapping
  • Pressing
  • Pinching
  • Dragging
  • Rotating

Adding gestures in our mockup tool is easy. Just click on the “Add event” option, select the gesture you want to implement, then define what happens next.

Download our mockup tool for free and try designing your own mobile app with these interactions!

Test on mobile devices

Certain gestures work in a given environment, others don’t. Maybe you want to test your horizontal scrolling with the swipe gesture. Avoid expensive oversights down the road and test out everything in your mockup!

Justinmind mockup tool lets you quickly and easily test your app designs in real-time on whatever mobile device you please. You can also quickly see changes to your mockup – want to make a small change to the toolbar? Just refresh the simulation and you’ll see the change in a matter of seconds!

Testing your mobile mockup in our mockup tool has several benefits, the main one being that you can see what works and what doesn’t. Check the results of the events and interactions you’ve added – does that animated transition make sense when changing pages?

Justinmind mockup tool - view your mobile mockups on your device

You can view and interact with your mockup on your desktop, your iOS or Android mobile device by downloading the Justinmind app from the App Store or Google play. Just click “View on device” and you’re good to go – without so much as a whisper of code.

You can also export your mockup as HTML so that it’s viewable in a web browser or even save the various screens of your mockup as images.

Create highly interactive mobile apps with the Justinmind mockup tool - download for free today!
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Free UI kits for web and mobile apps

In addition to being able to import your own UI kits, Justinmind offers a wide and varied range of free downloadable, responsive UI kits. With over 4,000 UI elements to design both interactive and screen mockups, it’s just a simple case of downloading the kit of your choice, and importing the library from your local drive.

Website mockups

Want to design the most authentic website user interface possible? Then you’re spoilt for choice with our website mockup tool. In addition to the widgets and UI elements already pre-installed in our mockup tool, the Justinmind website boasts an eclectic choice of web UIs, from Kendo to Bootstrap and from Saleforce to SAP Fiori.

Mobile app mockups

In terms of mobile app mockups, Justinmind has you covered with libraries containing every up-to-date UI element conceivable to create iOS and Android mockups. You’ll find everything for controls and layouts for native apps on both platforms, even two libraries of icon sets for both platforms – all for free!

Justinmind mockup tool - get access to over 4,000 widgets and elements

But the fun doesn’t stop there. Want to create mockups of native Apple Watch apps as well? Then don’t hesitate to download our Apple Watch UI kit that comes with icons, dialogs, controls and even examples for inspiration.

Download Justinmind for free and instantly gain access to the latest UI kits for iOS, Android and more!
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Design systems

Design systems let you reduce costs as well as work smarter and more efficiently. They not only revolutionize the way you work but also help prevent unscalable and clashing designs. Having a good design system is fundamental to successfully creating responsive, scalable apps and websites.

Justinmind mockup tool - create and maintain your own design system

The Justinmind mockup tool was built on the foundation of design system theory. Having a design system allows you to reuse components and maintain consistency across one or multiple mockups. The result? Stronger brand reinforcement!

Design forms and data lists

Form interaction and fields validation

Great form design is imperative to good user experience. That means testing the forms in your mockup is non-negotiable.

You may have heard, however, of some of the complexity that comes with validating field entries in forms, such as JavaScript and built-in validation, as well as server-side validation. Fear not! Our mockup tool lets you create interactive forms with field validation that you can test out immediately in a few simple steps, as well as letting you create conditional navigation flows for various user journeys.

Choose a “Forms and Inputs” widget from our widget library or download our pre-made forms to get your static form. Then it’s just a case of adding a success page, then some events and conditions to certain fields. Download our mockup tool and experiment with form design for free and see our tutorial for further information on how to validate field entries.

Data lists and grids

Our mockup tool lets you import real data into your mockups for a more authentic and accurate simulation.

Data lists

Data lists are a great way of allowing you to display detailed information. Data lists make information easier for the user to read as well enabling them to search for specific information. A great example would be if you wanted to horizontally list various individuals by order of name, email and company.

The Justinmind mockup tool lets you display master records in a data master list by simply clicking the data master tab and adding the appropriate widget to your mockup. You can import your data masters or even data from Microsoft Excel. Our mockup tool also allows you to add interaction to your data list such as allowing the user to add records or search for records using Events.

Justinmind mockup tool - add data lists to your mockup

Data grids

Data grids work much in the same way as lists, it’s just the visualization that’s different. They offer a more visual representation of your data. Instead of grouping names, emails and companies into list formats, like above, our data grids represent them in tabular format.

All it requires is adding one of your data masters to a data grid widget in our mockup tool. You can then customize the number of columns and cells in the grid. You can also choose to orient it vertically or horizontally and adjust the space between cells. And like data lists – you can even add interaction such as search filters by adding in some conditional events.

Don't scare your users away with bad forms - download Justinmind and master the art of form design!
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Collaborate with reviewers and developers

Share and get feedback from reviewers

Using the Justinmind mockup tool is not only great for creating high fidelity mockups, it’s also highly optimized for collaboration. Sharing your mockups and obtaining important feedback can take your mockups to the next level.

Our mockup tool allows several users to work on a mockup at once and communicate via the comments section. Users of Justinmind can even leave comments on various elements, events and interactions of the mockup.

Online collaboration is also possible with our mockup tool – have your stakeholders, product manager, clients and even users test your mockup remotely. You don’t need to have a Justinmind account to do it – as mentioned earlier – you can export your mockups in the form of HTML.

Enchance your team's collaboration with the Justinmind mockup tool

Having reviewers test your mockups on a mobile device is another great way of getting valuable feedback – but it’s not the only way. Justinmind’s collaboration with PhoneGap means you can now convert your mockup HTML code into native code, effectively allowing you to download and share native apps!

Design hand-off with developers

Designer-developer handoff has never been easier than with the Justinmind mockup tool. Have developers log in with developer accounts and guide them through the mockups. You can even conveniently export CSS style guides, while our mockup tool’s design repository ensures your developers have a consistent design system to follow when it comes time to code.

Generate functional specifications documents

Design handoff tools are a thing of the past – make developer handoff a breeze with Justinmind. Our mockup tool lets you instantly generate specification documents from your interactive mockups, making it a piece of pie to produce deliverables that can be printed off or distributed online and shared with colleagues, stakeholders and developers.

Justinmind mockup tool - generate specification documents for your mockups

These specification documents take all of the elements used in your mockup such as UI elements, templates, screens and interactions and provides an intuitive, easy-to read document, allowing developers to code your interactive mockup to life.

You can even create your own specification documents from our mockup tool in Microsoft Word by downloading an XML file with a hierarchical list of tabs from Justinmind.

Atlassian Jira

Many might say their design system wouldn’t be complete without their favorite proprietary issue tracking product. Atlassian Jira is fully integrated with our mockup tool – all you need to do is install the Justinmind-Jira add-on from the Marketplace. You’ll then be able to enjoy the full 360 experience of combining the best mockup tool with the most popular bug tracking and Agile product management software.

Once you install the Justinmind-Jira add-on, you’ll be able to both import and update Jira issues in the Justinmind mockup tool. But that’s not all, the integration also allows you to link your Jira issues to your mockup’s UI elements.

You can also view Justinmind issues (known as “requirements”) in the Atlassian Jira tool. You can even access any Justinmind mockups that you created from the issues in Jira.

Microsoft TFS

The Justinmind mockup tool is also integrated with one of the most popular collaboration tools – Microsoft Team Foundation Server (TFS), otherwise known as Azure DevOps and previously as Visual Studio Team Services.

You can import your Microsoft Azure work items into our mockup tool and link them to your mockups. Azure work items are viewed as requirements in Justinmind. Like with Atlassian Jira, the flipside is also possible here – you can view Justinmind requirements within Azure and from there, launch straight into a simulation of your Justinmind mockup.

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Integrate Sketch and Photoshop with our mockup tool

Import from sketch to create interactive mockups

Our mockup tool’s integration with Sketch lets you enjoy the best of both worlds. Design beautiful artboards, then instantly import them straight into the Justinmind mockup tool and see them transform into fully interactive, high-fidelity Sketch mockups, complete with animations, data masters and variables!

Create pixel-perfect mockups with the Justinmind-Sketch integration

Borderless, cross-functional work

The Justinmind-Sketch integration brings you collaboration like never before by successfully bridging the gap between cross-functional teams. Developers or other non-creatives who are not in possession of a Mac will be perfectly able to view and manipulate your Sketch designs using our mockup tool.


Gain full control of your artboards – simply export them to Justinmind in a few seconds, then manipulate them as you please, separating them into various different layers or maintaining the whole artboard as one image.

Effects and animations

Once you export your artboards you can bring them to life by adding events and interactions, as well as effects like transitions and animations, effectively turning your artboard creations into high-fidelity mockups.

But why stop there? This is your opportunity to create whole UI libraries and maintain a design system based on your Sketch designs! This way, you can harness the powers of Sketch to give you full control over your brand identity.

Interactive mockups from your Photoshop designs

Are you a dab hand with Photoshop? Would you like to be able to just design your mockups directly with the tool? Well, now you can! The Justinmind mockup tool is also integrated with Photoshop, allowing you to create mockups with your PSD files.

Turn your psd files into interactive mockups with the Justinmind mockup tool

Our mockup tool’s integration with Photoshop is seamless, meaning you can quickly and easily import your Photoshop designs into Justinmind.

With the Justinmind-Photoshop integration you can separate the layers of your Photoshop images or just use the full images. In fact, you can even create and define complete UI libraries with Photoshop and implement them into your design system. A complete design system based on Photoshop: the perfect companion to an atomic design system.

The plus side is that our mockup tool even looks and feels very similar to Photoshop, meaning that you’ll be working in a familiar environment!

Create highly interactive, pixel-perfect mockups with Justinmind's Photoshop and Sketch integrations
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The wrap up

The Justinmind mockup tool is your one-stop shop for all your mockup and collaboration needs. The best thing? It’s absolutely free to download! Given this, there’s absolutely no reason you and your team can’t start creating highly interactive mockups today and save time and money!

Joseph Downs
In-house UX copy-slinger, foodie and classic motoring enthusiast