Selenium WebDriver zoom in/out page content

Beware that Selenium assumes the zoom level is at 100%! For example, IE will refuse to start (throws an Exception) when the zoom level is different, because the element locating depends on this and if you changed the zoom level, it would click on wrong elements, at wrong places.

Java

You can use the Keys.chord() method:

WebElement html = driver.findElement(By.tagName("html"));
html.sendKeys(Keys.chord(Keys.CONTROL, Keys.ADD));

Use cautiously and when you're done, reset the zoom back to 100%:

html.sendKeys(Keys.chord(Keys.CONTROL, "0"));

C#

(since I realized C# bindings don't have the Keys.chord() method)

Or, you can use the Advanced User Interactions API like this (again, Java code, but it should work the same in C#):

WebElement html = driver.findElement(By.tagName("html"));

new Actions(driver)
    .sendKeys(html, Keys.CONTROL, Keys.ADD, Keys.NULL)
    .perform();

Again, don't forget to reset the zoom afterwards:

new Actions(driver)
    .sendKeys(html, Keys.CONTROL, "0", Keys.NULL)
    .perform();

Note that the naïve approach

html.sendKeys(Keys.CONTROL, Keys.ADD);

doesn't work, because the Ctrl key is released in this sendKeys() method. The WebElement's sendKeys() is different from the one in Actions. Because of this, the Keys.NULL used in my solution is required.

Here are two ways the zoom level can be altered with Java (one is for Chrome and the other is for Firefox):

Chrome

When using v̲e̲r̲s̲i̲o̲n̲ ̲3̲.̲3̲.̲1 of the Selenium Java Client Driver and C̲h̲r̲o̲m̲e̲D̲r̲i̲v̲e̲r̲ ̲2̲.̲2̲8, the following works (where the number in single quotes represents the zoom level to use; 1 = 100%, 1.5 = 150%, etc.):

JavascriptExecutor executor = (JavascriptExecutor)driver;
executor.executeScript("document.body.style.zoom = '1.5'");

Firefox

The zoom level can be modified with the following:
1. The aforementioned Java Client Driver
2. G̲e̲c̲k̲o̲D̲r̲i̲v̲e̲r̲ ̲v̲0̲.̲1̲5̲.̲0
3. These classes:
java.awt.Robot
java.awt.event.KeyEvent

First of all, instantiate the Robot class:

Robot robot = new Robot();

This code causes the zoom level to decrease:

robot.keyPress(KeyEvent.VK_CONTROL);
robot.keyPress(KeyEvent.VK_MINUS);
robot.keyRelease(KeyEvent.VK_CONTROL);
robot.keyRelease(KeyEvent.VK_MINUS);

This code causes the zoom level to increase:

robot.keyPress(KeyEvent.VK_CONTROL);
robot.keyPress(KeyEvent.VK_EQUALS);
robot.keyRelease(KeyEvent.VK_CONTROL);
robot.keyRelease(KeyEvent.VK_EQUALS);

Python approach working for me, except you have to specify the zoom level:

driver.execute_script("document.body.style.zoom='zoom %'")

Have 'zoom%' = whatever zoom level you want. (e.g. '67%'). This works for Chromedriver, which doesn't seem to accept the send_keys commands.

Zoom in | Zoom out Feature on Windows

Zoom in

WebElement html = driver.findElement(By.tagName("html"));
html.sendKeys(Keys.chord(Keys.CONTROL, Keys.ADD));

Zoom out

html.sendKeys(Keys.chord(Keys.CONTROL, Keys.SUBTRACT));

Zoom in | Zoom out Feature on MAC

Zoom in

WebElement html = driver.findElement(By.tagName("html"));
html.sendKeys(Keys.chord(Keys.COMMAND, Keys.ADD));

Zoom out

html.sendKeys(Keys.chord(Keys.COMMAND, Keys.SUBTRACT));

The most robust approach

Before you start with Internet Explorer and Selenium Webdriver Consider these two important rules.

1. The zoom level :Should be set to default (100%) and
2. The security zone settings : Should be same for all. The security settings should be set according to your organisation permissions.

How to set this?

Simply go to Internet explorer, do both the stuffs manually. Thats it. No secret.

Do it through your code.

Method 1:

//Move the following line into code format
DesiredCapabilities capabilities = DesiredCapabilities.internetExplorer();

capabilities.setCapability(InternetExplorerDriver.IGNORE_ZOOM_SETTING, true);

System.setProperty("webdriver.ie.driver","D:\\IEDriverServer_Win32_2.33.0\\IEDriverServer.exe");

WebDriver driver= new InternetExplorerDriver(capabilities);

driver.get(baseURl);

//Identify your elements and go ahead testing...

This will definetly not show any error and browser will open and also will navigate to the URL.

BUT This will not identify any element and hence you can not proceed.

Why? Because we have simly suppressed the error and asked IE to open and get that URL. However Selenium will identify elements only if the browser zoom is 100% ie. default. So the final code would be

Method 2 The robust and full proof way:

DesiredCapabilities capabilities = DesiredCapabilities.internetExplorer();

capabilities.setCapability(InternetExplorerDriver.IGNORE_ZOOM_SETTING, true);

System.setProperty("webdriver.ie.driver","D:\\IEDriverServer_Win32_2.33.0\\IEDriverServer.exe");

WebDriver driver= new InternetExplorerDriver(capabilities);

driver.get(baseURl);

driver.findElement(By.tagName("html")).sendKeys(Keys.chord(Keys.CONTROL,"0"));
//This is to set the zoom to default value
//Identify your elements and go ahead testing...

Hope this helps. Do let me know if further information is required.