What is Selenium WebDriver? Difference with RC

 What is Selenium WebDriver? Difference with RC

Introduction about WebDriver?
WebDriver:- Selenium WebDriver is a web automation framework and it is collection of open source APIs. It helps to execute ours tests on different web browsers like Chrome, IE, Firefox and Safari(not possible in Selenium IDE).

  • WebDriver supports following programming languages:-
    • .Net
    • Java
    • Ruby
    • Perl
    • Python
    • PHP

We just need to know one of the above given languages and in this session we will use Java languages with Eclips as our IDE.

What is difference between Selenium RC and Webdriver

Before Coming WebDriver(2006) we had another automation tool called Selenium Remote Control(Selenium RC).
WebDriver and Selenium Remote Control(Selenium RC) have some following common features:-For your test scripts designing both are allow to use programming language.Both are support different browsers for testing script.
Let us see how do they differ? .

1) Architecture

WebDriver’s architecture is simple than Selenium RC’s.
  • It eccess the browser from the OS level
  • We need our programming language’s IDE and a browser.
Selenium RC’s architecture is more complicated than WebDriver.
  • For Selenium RC we need to first launch a separate application i.e Selenium Remote Control (RC) Server before start testing
  • Selenium RC Server acts as a “mediator” between our Selenium commands and browser
  • When we start testing, Selenium RC Server “insert” a Javascript program called Selenium Core into the browser.
  • Once inserted, Selenium Core start to received instructions send by the RC Server from our test program.
  • When RC server instructions are received, Selenium Core will execute that instruction as JavaScript commands.
  • The browser will accept the instructions of Selenium Core and will send this response to the RC Server.
  • The Selenium Remote Control Server will receive browser’s response and then it display the results for us.
  • RC Server will retrieve the next instruction from our test script to repeat the whole cycle.

2. Speed

Selenium WebDriver is more faster than Selenium RC since it communicate directly to the browser and browser use own engine to control it.
Selenium Remote Ccontrol is slower than WebDriver because it uses a Javascript program called Selenium Core. This Selenium Core directly control the browser.

3. Real-life Interaction

WebDriver interacts with page elements in a more realistic way. For example, if you have a disabled text box on a page you were testing, WebDriver really cannot enter any value in it just as how a real person cannot.
Selenium Core, just like other JavaScript codes, can access disabled elements. In the past, Selenium testers complain that Selenium Core was able to enter values to a disabled text box in their tests. Differences in API

4. API

Selenium RC’s API is more matured but contains redundancies and often confusing commands. For example, most of the time, testers are confused whether to use type or typeKeys; or whether to use click, mouseDown, or mouseDownAt. Worse, different browsers interpret each of these commands in different ways too!
WebDriver’s API is simpler than Selenium RC’s. It does not contain redundant and confusing commands.

5. Browser Support

WebDriver can support the headless HtmlUnit browser

HtmlUnit is termed as “headless” because it is an invisible browser – it is GUI-less.
It is a very fast browser because no time is spent in waiting for page elements to load. This accelerates your test execution cycles.
Since it is invisible to the user, it can only be controlled through automated means.
Selenium RC cannot support the headless HtmlUnit browser. It needs a real, visible browser to operate on.

Limitations of WebDriver

WebDriver Cannot Readily Support New Browsers

Remember that WebDriver operates on the OS level. Also, remember that different browsers communicate with the OS in different ways. If a new browser comes out, it may have a different process of communicating with the OS as compared to other browsers. So, you have to give the WebDriver team quite some time to figure that new process out before they can implement it on the next WebDriver release.
However, it is up to the WebDriver’s team of developers to decide if they should support the new browser or not.

Selenium RC Has Built-In Test Result Generator

Selenium RC automatically generates an HTML file of test results. The format of the report was pre-set by RC itself. Take a look at an example of this report below. WebDriver has no built-in command that automatically generates a Test Results File. You would have to rely on your IDE’s output window, or design the report yourself using the capabilities of your programming language and store it as text, HTML, etc.


  • WebDriver is a tool for testing web applications across different browsers using different programming languages.
  • You are now able to make powerful tests because WebDriver allows you to use a programming language of your choice in designing your tests.
  • WebDriver is faster than Selenium RC because of its simpler architecture.
  • WebDriver directly talks to the browser while Selenium RC needs the help of the RC Server in order to do so.
  • WebDriver’s API is more concise than Selenium RC’s.
  • WebDriver can support Html Unit while Selenium RC cannot.
  • The only drawbacks of WebDriver are:

It cannot readily support new browsers, but Selenium RC can. It does not have a built-in command for automatic generation of test results.

Leave a Reply

Your email address will not be published. Required fields are marked *