With more plugins, apps, features, and possible capabilities than ever, businesses and web designers can easily overcrowd their digital experiences by stuffing their sites to the brim with functionality.

But as anyone familiar with UX design methods and the Design Thinking process will know, you don’t have to sacrifice simplicity and clarity in the name of function. In other words, you can have a website with highly-complex features and capabilities that is no more difficult to use than Google.

Here are four carefully selected web design case studies that, when done right, simplicity and function can make the perfect pair.

1. HubSpot

HubSpot offers a multitude of different services and, as a web-based business, needs to communicate — as well as deliver — them all to its four million monthly visitors through its website.

As a business grounded in data, the design of HubSpot’s site is heavily influenced by Google Analytics and important metrics like conversation rate, submission rate, goal completion, and drop-off rate. By tracking these markers and involving users throughout the entire development process, HubSpot’s website manages to convey a tonne of information without overloading the user.

HubSpot is also the first in our pick of web design case studies for: its use of colours such as red to draw the user’s attention, the generous serving of white space, and features that scroll with you such as live chat, one-click translation, and a search function.

2. Mezzino

As a student accommodation service that is rapidly growing and which relies heavily on its web presence, Mezzino needs a website that was incredibly simple, functional, and high performing.

This is reflected in the choice to place a search function in the main banner on the homepage as well as quick call to actions such as ‘Call Me Back’, Arrange a Viewing’, and ‘Reserve Now’ in the header. With help from its contrasting colours and clutter-free design, this allows users to get where they need to be with just a few clicks.

Another element of Mezzino’s web design that helps the site appeal to its student market, is the clear display of social proof. Just above the footer on most of the site’s pages are scrolling testimonials, along with cheery photos, from many of its happy tenants.

3. FitBit

The leading health and fitness smartwatch on the market, FitBit as a brand has become so popular exactly due to simplicity and functionality. And when users or new customers go to its site, that’s exactly what they get.

Designed according to IDEO’s Human-Centered Design framework and Lean UX Design principles, the site manages to not just appeal to die-hard fitness freaks but novices and absolute beginners too. This last category, which makes up a large segment of its users, is catered to beautifully with the ‘Why FitBit?’ page.

The full-page interactive journey uses simple, honest copy and relatable images to take users from its manifesto to its entire product line. And rather than pushing for the hard sell in the final slide, it recognises the users need to then go and make an informed decision on their terms with a ‘Compare All Products’ button.

4. Houzz

Houzz has become the go-to place for everything interior design. Whenever users are looking for inspiration for the home, need a professional in their area, or want a specific piece of furniture, they go to Houzz.

With design being such a core part of its business offering, Houzz’s website needs to not only look incredible but function impeccably. This isn’t easy when you have over fifteen million photos to organise, but with its clean colour scheme, grid-like structure, and clear typography, it manages to do it in style.

Houzz particularly excels in its search functionality. Users can filter photos by selecting criteria like home gyms and bars, styles like shabby-chic and coastal, and sizes such as compact and expansive. Social proof is also prominent with its user rating system and question and answer feature — ideal additions for its socially conscious target market.