Web developer Interview Questions & Answers (2025)

As a web developer, most of the time entire responsibility of the project is shouldered on us. Major of them are:

• Developing the appropriate structures for the project
• To provide assistance with the maintenance of websites.
• Also to have the ownership of code throughout the development and testing.
• To coordinate with the designers.
• To fix the error and resolve problems.
• To upload the site successfully over the servers.

CORS stands for the cross-origin resource sharing. It is actually a mechanism which enables the sources on a webpage to get permitted from other domain which is actually located outside the domain from where the source gets originated. This mechanism is supported in HTML5 that also manages the request (that is HTTP) access to a domain differentially.

As a web developer, there are multiple tasks that have to be performed like designing, programming, developing and testing the project several times. The technical proficiency which a web developer must essentially have is:

• HTML
• CSS
• SQL
• PHP
• JavaScript
• jQuery

There are multiple advantages of http/2 if compared to http1.1. The major among them are-

• Http headers data compression
• Request prioritization.
• Parallel loading of page elements over a single TCP connection.

Yes, there are three types of popup boxes in JavaScript. They are:

• Alert - it displays a message with an OK button.
• Confirm- basically pops up a message window which is actually a confirmation with OK and cancel button.
• Prompt - dialogue box gets pop-up through it which asks the user’s input followed with the confirmation buttons.

An ETag is actually an identifier which is assigned by a web server to any of the specific version of a resource. It is done where the URL is found. The ETag instantly changes if the resource content over the URL changes. In this case, the client can ask to cache the resources along with its ETag.

Stateless protocol- A communication protocol which screens every request as an independent transaction is a stateless protocol. Hence, it is not required from the server to retain any of the session or identity in order to optimize multiple requests arriving from the same source. HTTP is a stateless protocol as it does not require the server to retain information from multiple requests.

Stateful protocol - A communication protocol where the responder maintains the information safely across multiple requests originating from the same source is called stateful protocol.

GET:

• If the data is sent in the form where parameters are same, then they will be visible in the URL.
• The parameters will be appended to the URL.
• There will be less security during the uploading out to the server.

POST:

• A large amount of data can be sent.
• It is comparatively secure.
• Data can be sent after using the encryption method in the body of an HTTP request.

In computer programming, there is a common designing pattern which is known as lazy loading. In order to precede the initialization of any of the object until the segment where it is needed essentially, it is used. If user needs then lazy coding is a loading code (in reference to use). Example - Under page, a button is present which shows multiple layouts the user can switch to.

It is known that JavaScript reads line by line. In a few cases, the general line of code gets executed prior to an earlier code. Under the circumstances, callback code is used to prevent this because this code is not called until the previous line has been executed efficiently.

The functions which are without any actual name are called anonymous functions. These functions are stored in a variable and automatically get invoked using the same variable name.

Ajax stands for Asynchronous JavaScript and XML. It allows applications to translate the data from a server asynchronously without actually refreshing the whole page. Data can be sent or retrieved with the same method. For example, even if you have refreshed the page new email appears and marked as new.

In an HTML document, the doctype is the first fundamental declaration even before the HTML tag. Doctype is quite different from the HTML tag as it is an instruction which is given to the web server about the version of the markup language in which the pages is written. It also refers to a document type definition which specifies all the limitations for the markup language. In this condition, the browser can render the contents accurately.

In order to increase the page performance following methodologies can be opted:

• Caching
• Concatenate the JavaScript or CSS
• By including the JavaScript at the bottom of page
• With compressed or smaller images.

Yes, Jasmine and Qunit are the JavaScript testing frameworks which are essentially important for scripting.

There are a number of methods that can be performed like-

• Caching
• To reduce lookup
• Minimization of redirects
• Http compression