22 Front End Interview Questions - Beginner to Advanced Level Questions

Trying to find a job in front end development? You’ll need to be able to prove that you have an inside-out knowledge of the subject, even under the high pressure of an interview setting. That means you’ll need to be ready to answer some common front end interview questions, including:

• What coding languages do you have experience with?
• How do you deal with negative client feedback?
• What is user-centered design?
• How do you prioritize accessibility in your work?
• What are the elements of the CSS BOX model?

Front end development is a multi-faceted topic, so you can expect to face a broad range of questions. You’ll need to put the work in to prepare if you want a shot at getting the job.

We’ve put together a list of common interview questions about front end development, along with some example answers that you can build on as you prepare. Keep reading, and you’ll be ready to tackle any question that comes your way!

Front End Interview Questions

To give yourself the best chance of acing your interview, you’ll need to prepare for all the most common front end interview questions. Here are some of the most common questions you may have to answer at interview:

What is front end development?

Front end developers create the interface that users see when they access a web page. Front end development involves taking the code created by back end developers and turning it into a format that users can understand, interact with, and explore. Without front end developers, the internet would only be accessible to people with a background in coding – the internet as we know it would not exist at all.

What is a front end developer’s role on a team?

Front end developers need to work closely with both clients and back end developers to deliver a cohesive, functional product. They should have an in-depth understanding of coding languages, to enable them to deliver a web interface that works as intended, but also an understanding of design so they can create something visually appealing. They need to be able to collaborate effectively, as their work is usually done in partnership with other team members.

What skills are most valuable to you as a front end developer?

As a front end developer, it’s important to have the following skills:

• In-depth knowledge of different coding languages
• Testing and debugging skills
• Version control and code tracking skills
• Teamwork and communication skills

What coding languages are most commonly used in front end development?

Front end development makes prominent use of HTML, which is used to define and mark the content of a web page so it displays correctly within a browser. It also uses CSS to create and define the style of a web page, addressing elements such as animation, layout and color. The other main element of front end development is JavaScript, which makes a site dynamic and interactive for the user.

What are some ways to ensure that other developers can understand your code?

As front end developers have to work closely with back end developers in particular, it’s important to ensure that any code is accessible to colleagues. That means keeping code clean, straightforward and organized, avoiding deep nesting wherever possible and limiting the length of each line. It can also be helpful to offer colleagues additional input, such as comments within the code or a separate style sheet.

How do you prioritize accessibility in your work?

Front end developers can employ a number of easy techniques to make their work more accessible to everyone. It can be helpful to add features such as alt text for images, which enable screen readers to describe the images to users with visual impairments, or functionality that allows users to shrink or enlarge a web page’s font. It’s also a good idea to test any web pages or applications on multiple browsers and devices, to ensure that as many users as possible can access the site as designed.

How do you stay up to date with new developments and trends in the industry?

To deliver the best possible work for clients, front end developers need to stay informed about any new trends or developments in the field. Reading relevant magazines, blogs, and news sites can provide some insight into the state of the industry. Developers can also learn about prevailing trends by browsing the internet and paying attention to the design techniques they see.

What is user-centered design?

User-centered design is an iterative design procedure that allows developers to focus on their clients’ needs throughout every stage of the process. It seeks to involve clients and end users in the work of design and development through brainstorming sessions, surveys, interviews, and other research techniques. While it can be more time-intensive due to the research requirements involved, it allows developers to build a more user-friendly and purpose-driven product, increasing client satisfaction.

What are the best ways to deal with negative client feedback?

Front end developers need to be able to work to a brief, keeping their clients’ specifications in mind. That means that it’s best to respond to criticism from clients graciously and proactively, making any requested changes promptly. Developers should also try to prevent negative feedback from clients by paying close attention to briefs and specifications, and adhering to them carefully at every step of the process.

How do you limit errors in your work?

Testing and checking work are important skills for any front end developer. It’s important to double- and triple-check all aspects of any code, to make sure it is clean, functional and understandable. Launching a web page or application in multiple different browsers or platforms can help to reveal any errors, too.

How can you decrease page load time?

Decreasing page load time is usually fairly straightforward, and can greatly improve the user experience. Implementing a browser cache can boost the loading speed for pages that users have already visited, enabling repeat visitors to your web page to experience faster loading times. Developers can also scale any videos and pictures before uploading them to a page, or compress any other large content. Setting the stylesheet reference to the header of a HTML document can also allow a page to load more quickly.

What is progressive rendering?

Progressive rendering involves rendering portions of a web page sequentially in the server. The web page is then streamed to the client in parts, without the need to wait for the entire page to be rendered. Progressive rendering is used in modern web development to limit a web page’s demands on mobile data usage, prioritizing the loading of content that is immediately visible to the user.

Front end developers can support progressive rendering by loading critical CSS in the head of the page. It’s also helpful to use the CSS grid system to lay out a web page, as it removes the need for the content of a web page to be streamed to the user in a sequential order.

What are HTML meta tags?

Meta tags, within HTML code, don’t appear visually on a web page. Instead, they exist to provide information about the web page. Meta tags usually contain data about the HTML document’s author, title, character set, or keywords.

What are REST web services and why would you opt to use them?

REST stands for Representational State Transfer, which sets out the specifications that enable services to work best on the web. REST web services perform well, can scale easily, and can be modified easily when required.

REST web services work on the HTTP protocol, and are easy to learn and understand. They are lightweight and easy to use, and can be tested without difficulty in browsers. They also support multiple technologies for the transfer of information, making them more reliable than alternatives.

What are the elements of the CSS BOX model?

The CSS box model contains four elements, nested from the outside in. From the innermost element to the outermost, they are:

Content, which displays the main content of any web page Padding, which encircles the content Border, which acts as the padding’s outer layer Margin, which is the area outside of the border

What is the grid system in CSS?

CSS divides the web page into grids, which it then utilizes to manage the web page’s HTML content. Using the grid system in CSS enables a developer to stack and highlight elements of the page in different areas of the grid. The grid system also removes the need for elements of the page to load in a strictly sequential order, which can help to improve web page loading times.

When would you use div and span elements in HTML?

Div and span elements are both used to group together related parts of a web page. However, a div element is used to organize and style whole blocks of page elements. This makes it easier to identify different sections of a web page, and to apply different styles to each section using CSS.

A span element, meanwhile, is used to organize and style a particular portion of inline content on a web page. Span tags are typically used on small sections of content that appear inline with the surrounding content.

Why do we no longer use data-* attributes in HTML?

In HTML, data-* attributes have historically been used to store custom private data relating to the web page or application. It enabled developers to embed custom data attributes within any HTML element on a page. The stored data could then be used in a web page’s JavaScript to tailor the page to an individual user, creating a more engaging experience.

However, it is now considered inadvisable to use data-* attributes. This is because users can change the attribute easily in their own browser inspect console.

When would you use the srcset attribute in an image tag?

The srcset attribute is applied to a HTML image tag in order to generate a particular resolution of an image on a web page, according to the device on which the web page is loaded. Using srcset, a web page will display an image in low resolution on older, smaller or lower-end devices, and will display a higher resolution of an image on larger or higher-end devices. This improves the user experience of a web page.

You would use the srcset attribute when designing an image-heavy page intended for use across a range of platforms, including mobile browsers and older devices.

What is React and why is it used?

React is a free, open-source front end JavaScript library, used for building user interfaces. It allows developers to construct complex user interfaces from so-called “components” – small, isolated pieces of code. It is built to be efficient, flexible and scalable, and it can be used in combination with other JavaScript frameworks or libraries.

React is maintained by a dedicated staff, and is regularly updated with bug fixes, enhancements, and documentation. It’s designed to be simple to learn, which makes it popular with developers at all levels of skill and experience. And it has an active community that makes amazing contributions to the available resources.

What is the anonymous function in JavaScript and why is it used?

In normal user-defined functions, defining the function involves defining the function name. However, anonymous functions do not have a defined function name at all. Anonymous functions can be used as an argument to other functions, or as an immediately invoked function execution.

What is the stringify function in JSON and why is it used?

JavaScript Object Notation (or JSON) is commonly used to exchange data with a web server. However, in order for a website to send data to a web server, that data has to take the form of a string. The stringify function in JavaScript can be used to convert any JavaScript object into a string.

That object, in string format, can now be exchanged with any web server. This enables much more efficient communication between a web server and a web page.