In the early stages of software product development, companies go through numerous idea iterations. To stick with the lean process and keep the costs down, these iterations normally don’t happen on the end-design level, but rather with wireframes. Especially paired with style-tiles later in the process, this can prove to be a very agile and quick method for developing new, well-designed products.
Whether you’re a fortune 500 company or a one-man-band, you’ll find it tremendously useful to pinpoint the issues early and to quickly develop the basic hierarchy, layout, and content layout in the interface. Here are 10 free wireframe tools that will help you with this task.
But before you dive in, you may also like to read this post on 15 essential rules for designing intuitive interfaces.
MockFlow

MockFlow has a selection of starting templates available, among others are Bootstrap UI, iPhone app, Android app, and even WordPress theme. These templates import the interface components that you’ll likely need for your project. Useful! As I tested it, the app was actually a breeze to work with. Account upgrades start at $14/month.
Whiteboard or Paper

If your team is around you and not on the other end of the world, the absolute best way to plan out an app is to grab a stack of papers and brainstorm the heck out of the ideas. Best part of this approach? There is no learning curve — you already know how to hold a pencil. If you want to step it up a bit, use a whiteboard — or even a whiteboard-notebook!
Google Drawings

I was surprised to see that this tool has improved quite a bit since I used it last time. It works smoothly, and even some of the keyboard shortcuts I’m used to from Adobe Suite work here! You can paste in your own images, and if you want stencils to play around with, you can use the free Docs templates like this one. Sharing is integrated, and if you have a Gmail account, you can start using Drawings right away. Want an advanced version with a similar interface? Try Draw.io.
Wireframe.cc

You don’t even have to sign up to this awesome little wireframe tool — just open it up and start working. It supports copy-pasting and inserting images. For multiple paged documents, version management, pdf export, and clickable elements, you’ll need to pay $12+ per month. But worry not, because the wireframes created with the free version are always shareable with links.
Moqups

This app has a drag-and-drop interface with a number of neat components you can use. It supports pages, revisions, and sharing even in the free version — your only limitation is storage and number of projects (maximum of 2). It’s really no wonder why this tool is so popular. For some additional options like master pages, collaboration, etc. you’ll be $9 poorer every month.
FluidUI

To say that this app is impressive would be an understatement. It features a very unique user experience and lets you plan the entire workflows within your mobile app, and even test it on your own device. It costs $12/month if you want to export your screens into .pdf or work with more than 10 screens.
Gliffy

This app is nothing too special on this list. Things work as they’re supposed to, and the free version is really very unlimited. If you ever decide to upgrade anyway, it’ll cost you less than $5 per month, which is very very cheap. Gliffy also supports drawing flowcharts and mindmaps, so if you’re into that kind of things it may be a great idea for you to invest into learning to use this app.
NinjaMock

What’s up with all these SaaS startups naming themselves ninja-something? Anyway, these guys offer a few device templates to get you started, and after that you get a ton of fun, freehand-style components you can use in your designs. I like simple components that make it obvious that this is nowhere near the final design. You’d be surprised how many clients of mine were super disappointed at the white-grey designs I prepared (they were actually wireframes). When I drew them in my sketchbook, everybody understood it was just a sketch.
MockingBird

MockingBird has been going strong for a few years now. The interface is slightly outdated, but the app works pretty well. If offers all the standard features you’ll find in your average wireframing app. If you want to create more than a single project however, paid plans start at $9/month.
Cacoo

Another oldie but goldie is Cacoo. While the app loads quite slowly, it offers an entire library of wireframing templates — from iPhone to Google homepage. If you don’t mind the design from 00’s, this feature-full app may be what you’re looking for. The free version is quite generous, but if you ever decide to upgrade, it’ll cost you a little less than $5/month.
There we are, 10 tools you can use to mockup your product even if you’re on a shoestring budget. Now you don’t have an excuse to not start testing usability of your app or even validate your idea without any extra-skills.
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