Best Free Responsive Web Design Testing Tools

Let’s say you’ve decided to create a website and completed its design. What will the next step be? Of course, you should get down to testing. This step will help you understand how well your website displays on screens of different sizes and in various browsers. Testing is an essential step in the web design process. It will help to correct errors and make the resource more convenient, technological, and functional.

These days a wide range of gadgets is becoming more accessible and affordable; there are many gadgets you can view websites on, such as phones, tablets, laptops, netbooks, PCs, and even TV. Before the release, you should test how the content will be displayed to different users.

Fortunately, it is quite easy to do. There are many great free responsive web design testing tools on the Internet to help you check if your website design matches various devices in a user-friendly way or not. Websites should be user-friendly and responsive to various devices. Creating a smart, flexible, adaptable web interface with responsive web design will help you become more visited and inspire readers.

In this article, we’ve selected the best tools and resources to help you adapt your website to a number of gadgets varying in size and operating system. They do not need special knowledge of coding.

Why is testing necessary?

The number and range of portable devices multiplies every day. All of them differ in resolution, size, color reproduction, and dozens of other aspects. Since technology does not stand still, it is necessary to improve and expand the market for devices as well as the web development sphere.

A long time ago, websites used to have a separate version with the ‘m’ prefix in the address bar for mobile gadgets. For example, this happened to >

Everything has changed since then. To open the website on a mobile device nowadays, you need to create a specially adapted view that will be adjusted according to all the requirements. Testing is the most important stage that will help to check whether:

  • The design looks nice on mobile devices;
  • Blocks, pictures, icons have shifted;
  • The font is readable;
  • There are any distortions in the logos;
  • The multimedia works correctly;
  • Pop-ups are displayed normally.

The principle of testing is to adapt all performance and visual indicators to certain gadget screens.

Responsive web design itself is an approach to screen orientation and consistency in the design of the Internet pages with the screen settings. There are no defined rules that will be universal for any site and application; everything is calculated and tested individually.

The placement of the text and scrolling of dynamic blocks should be optimal on the maximum number of mobile devices (from tablets to mobile phones).

Sometimes it’s difficult to buy all the possible gadgets to use them for testing. Therefore, there are so-called simulators that integrate your design into different parameters and create a picture for you to see if any changes are necessary. With the help of existing plugins and add-ons for them, there is no need to spend money on devices to test everything manually. In addition, these add-ons are quite simple, so even inexperienced people will be able to use them.

Responsive Design Bookmarklet

Responsive Design Bookmarklet is a convenient tool for testing responsive design. It can be applied directly to your browser. It works by the principle of plugin, shows which Media Queries are active at the current browser width.

When you save the CSS file, the changes are made directly, without the need to refresh the browser you are working with. If you have completed all the necessary actions, close the bookmarklet and return to the page. This allows you to view the current page on screens corresponding to the size of tablets and smartphones.


jResize is an responsive web development tool built into jQuery that helps developers to adapt the projects to fit different devices. Frames of various widths are included. Thus, it becomes quite easy to resize the HTML in the browser. All you have to do is download jResize. When you select the desired width, the size changes accordingly.


ResizeMyBrowser is a responsive web design tool that allows you to select browser sizes for testing. Users can choose between 15 different presets or enter their own settings. is a tool for testing responsive designs with a perfect pixel. This allows you to test your responsive design at 30 different preset device resolutions or check it by resizing the window.

Responsive Calculator

Responsive Calculator is a tool that allows developers to convert a pixel to a percentage in a given context. This will help you turn your PSD into a successful, responsive website project. Its advantage is an intuitive interface.


Screenfly from QuirkTools is an online digital modeling tool that allows users to view their responsive websites. Here you will see a desktop, tablet, mobile phone, and TV. Screenfly is easy to use, it provides a wide range of features, such as visualization on desktop monitors of various sizes and on a virtual television screen. In addition, here you can enable or disable scrolling options, or even display rotation option.


Responsinator is a cool tool (online portal) that allows you to view a web page on smartphones and tablets in both portrait and horizontal mode. In addition, Responsinator gives you the chance to view your site on multiple screens at the same time (the option is perfect for those who need to compare something and make changes at the same time). Just enter the URL and view the design on your iPhone, iPad, Kindle, and Android phones.

Viewport Resizer

Viewport resizer is a browser-based tool that allows users to check the response from any website. Users just need to save the bookmarklet, go to the page that should be tested, click on the created bookmarklet, and check all types of screen resolutions.


It is a simple and useful tool that requires only a URL to enter a site or page to start testing.


Developed by Edward Kent, ReView is a dynamic system that provides efficient and convenient options of view mode. Users can choose between Opt-In and Opt-Out response states. This is one of the best testing tools.

Designmodo Responsive Test

Designmodo Responsive Test is a responsive website testing tool that helps you test your project in a range of different screen sizes. Just enter the URL and select the device type (or enter your custom preferences).

Adobe Edge Inspect

Adobe Edge Inspect CC allows you to check web design on various devices for consistency of images and icons. This allows you to synchronize the remote view tool, take screenshots, integrate tools, expand, compress, and much more.


This is a cool online portal for testing. It allows you to change the size of the site in pixels. This feature allows you to test CSS media queries on your website.


This is an online simulator for mobile devices and tablets, which will help you test the website on various devices, such as tablets, PC desktops (various monitor sizes), mobile phones, and so on. Just enter the URL of your blog, site or page, and select the device. You will immediately see a picture of how the project looks on a different display.


This is one of the easiest tools that will be useful even for beginners. There are no excessive tools and buttons, only the important things. There are four formats – PC (1600 by 992), laptop (1280 by 802), tablet computer (768 by 1024), and smartphone (320 by 480). All numbers are indicated in pixels.


This tool is an analogue of the previous one, but with a more advanced package of features and devices. All resolutions are displayed on the main page in the horizontal console. There are tools for editing the background and title size, moving the logo, and creating a screenshot. Deviceponsive gives you the following options: 1280 by 800 pixels (Mac), 768 by 1024 pixels (iPad), 1024 by 768 pixels (iPad), 1024 by 600 pixels (Kindle), 320 by 480 pixels (iPhone), and 240 by 320 pixels (standard smartphone).

A distinctive feature of the service is that it includes scroll bars so that the designer checks every centimeter of the project.

Responsive test 

It has a wide selection of different gadgets to demonstrate the adaptability of the project. The service menu is quite clear and simple; the zoom tool is well developed here. It is different from the tools mentioned above, as it has more than three dozen different resolutions, which means you can test the page for the maximum number of potential users and create an responsive design for everyone.

However, the tool has some issues when working with the Firefox browser. The reason is not clear, but it seems that the plugin and the browser have a conflict. Unfortunately, this issue is not solved yet. has a significant advantage over its competitors – a set of smooth animation when changing one “device” to another. There is also a translucent background, which helps to see the site’s real size, not just the current working unit.

There is a standard PC resolution, tablet, smartphone ones. The phone and tablet can be tested with the auto-rotate option – both vertically and horizontally.

Its significant minus is that you cannot set custom presets in pixels.


Over ten phones and over ten tablet models are available here. Such a variety will make testing the future site as productive as possible. There is a tool for quick auto-rotation from portrait to landscape mode.

All notes and test results are displayed on a special linear grid. By the way, measuring the proportions and parameters of blocks with millimeter accuracy is possible using this grid.


Many experienced and reputable designers say that Screenfly is the most versatile and convenient tester tool for responsive design.

There are a lot of devices here: 9 tablet options, the same number of smartphone models, 3 TVs, and a template for custom resolutions. That means that you can take advantage of the proposed standard options and implement your project for non-standard screen resolution.

It is also convenient that by pressing just one button, you can send the monitoring results to your colleagues.

The responsive calculator

With the help of this service, every specialist will be able to convert the PSD project to the necessary percentage while watching the responsive version. There is also a wide selection of the most popular devices – from minimal mobile to max desktop ones.


It is a completely free tool that allows you to evaluate your Internet resource’s mobile productivity coefficient. To use Mobitest, enter the link in the field and click on the ‘Start’ button.

The resource works quite quickly, so you do not have to wait long to download pages or entire websites. A nice addition is that you can ask the program to create a report in the form of a diagram on the compatibility of the site.

Mobile emulator from Google

This is a special virtual manager that will help you see the display of the website in a mobile interface in real-time. It includes phones with various operating systems, and tablets from 8 to 10 inches.

There are certain deviations in this method, so the result is not always 100% accurate. However, the calculations of Google mobile emulator today are the most economical solution.

Key features

  • Checking the look of text blocks;
  • Click-ability;
  • True to color shades;
  • Edges and borders;
  • Fonts and styles;
  • Scrolling correctness check.


Always try to use one of the suggested monitoring options to test your web product.

Since the principle of their work is approximately the same, you can choose any of them that is more suitable in terms of functionality and interface. All the above examples of plugins have a free version; some of them have advanced options for an additional fee.

Such tools will help eliminate possible errors that may cause discomfort to readers and visitors. They will also help correct inaccuracies in the operation of buttons, opening blocks, pop-ups, dialog spaces, and so on.

Using free tools for testing web design is a professional approach that will ensure the comfortable use of the website.

Mike Blitz

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