Control the size and orientation of the screen for your application.

You can set the viewport's width and height globally by defining viewportWidth and viewportHeight in the configuration.

Syntax

cy.viewport(width, height)
cy.viewport(preset, orientation)
cy.viewport(width, height, options)
cy.viewport(preset, orientation, options)

Usage

Correct Usage

cy.viewport(550, 750) // Set viewport to 550px x 750px
cy.viewport('iphone-6') // Set viewport to 375px x 667px

Arguments

width (Number)

Width of viewport in pixels (must be a non-negative, finite number).

height (Number)

Height of viewport in pixels (must be a non-negative, finite number).

preset (String)

A preset dimension to set the viewport. Preset supports the following options:

orientation (String)

The orientation of the screen. The default orientation is portrait. Pass landscape as the orientation to reverse the width/height.

options (Object)

Pass in an options object to change the default behavior of cy.viewport().

Yields

• cy.viewport() yields null .
• cy.viewport() cannot be chained further.

Examples

Width, Height

Resize the viewport to 1024px x 768px

cy.viewport(1024, 768)

Organize desktop vs mobile tests separately

describe('Nav Menus', () => {
  context('720p resolution', () => {
    beforeEach(() => {
      // run these tests as if in a desktop
      // browser with a 720p monitor
      cy.viewport(1280, 720)
    })

    it('displays full header', () => {
      cy.get('nav .desktop-menu').should('be.visible')
      cy.get('nav .mobile-menu').should('not.be.visible')
    })
  })

  context('iphone-5 resolution', () => {
    beforeEach(() => {
      // run these tests as if in a mobile browser
      // and ensure our responsive UI is correct
      cy.viewport('iphone-5')
    })

    it('displays mobile menu on click', () => {
      cy.get('nav .desktop-menu').should('not.be.visible')
      cy.get('nav .mobile-menu')
        .should('be.visible')
        .find('i.hamburger')
        .click()

      cy.get('ul.slideout-menu').should('be.visible')
    })
  })
})

Dynamically test multiple viewports

const sizes = ['iphone-6', 'ipad-2', [1024, 768]]

describe('Logo', () => {
  sizes.forEach((size) => {
    // make assertions on the logo using
    // an array of different viewports
    it(`Should display logo on ${size} screen`, () => {
      if (Cypress._.isArray(size)) {
        cy.viewport(size[0], size[1])
      } else {
        cy.viewport(size)
      }

      cy.visit('https://www.cypress.io')
      cy.get('#logo').should('be.visible')
    })
  })
})

Preset

Resize the viewport to iPhone 6 width and height

cy.viewport('iphone-6') // viewport will change to 414px x 736px

Orientation

Change the orientation to landscape

// the viewport will now be changed to 736px x 414px
// and simulates the user holding the iPhone in landscape
cy.viewport('iphone-6', 'landscape')

Notes

devicePixelRatio

devicePixelRatio is not simulated

Follow #7075 if you need this supported.

Restores

Cypress will restore the viewport in the snapshot

When hovering over each command, Cypress will automatically display the snapshot in the viewport dimensions that existed when that command ran.

Defaults

Default sizing

By default, until you issue a cy.viewport() command, Cypress sets the width to 1000px and the height to 660px by default.

You can change these default dimensions by adding the following to your configuration file (cypress.json by default):

{
  "viewportWidth": 1000,
  "viewportHeight": 660
}

Additionally, Cypress automatically sets the viewport to its default size between each test.

Scaling

Auto Scaling

By default, if your screen is not large enough to display all of the current dimension's pixels, Cypress will scale and center your application within the Cypress runner to accommodate.

Scaling the app should not affect any calculations or behavior of your application (in fact it won't even know it's being scaled).

The upsides to this are that tests should consistently pass or fail regardless of a developers' screen size. Tests will also consistently run in CI because all of the viewports will be the same no matter what machine Cypress runs on.

Reset viewport via Cypress.config()

You can change the size of the viewport height and width for the remainder of the tests by setting the new values for viewportHeight or viewportWidth within Cypress.config().

Cypress.config('viewportWidth', 800)
Cypress.config('viewportWidth') // => 800

Set viewport in the test configuration

You can configure the size of the viewport height and width within a suite or test by passing the new configuration value within the test configuration.

This will set the height and width throughout the duration of the tests, then return it to the default viewportHeight and viewportWidth when complete.

describe(
  'page display on medium size screen',
  {
    viewportHeight: 1000,
    viewportWidth: 400,
  },
  () => {
    it('does not display sidebar', () => {
      cy.get('#sidebar').should('not.be.visible')
    })

    it('shows hamburger menu', () => {
      cy.get('#header').find('i.menu').should('be.visible')
    })
  }
)

Rules

Requirements

• cy.viewport() requires being chained off of cy .

Assertions

• cy.viewport() cannot have any assertions chained.

Timeouts

• cy.viewport() cannot time out.

Command Log

Change viewport size to test responsive nav

cy.get('#navbar').should('be.visible')

cy.viewport(320, 480)

// the navbar should have collapse since our screen is smaller
cy.get('#navbar').should('not.be.visible')
cy.get('.navbar-toggle').should('be.visible').click()
cy.get('.nav').find('a').should('be.visible')

The commands above will display in the Command Log as:

When clicking on viewport within the command log, the console outputs the following:

History

See also

• Read blog post Use meaningful smoke tests where we run the same test with different viewport resolutions
• Read blog post Generate High-Resolution Videos and Screenshots to learn how to change the browser's window size to capture screenshots and videos with more detail
• Configuration
• Cypress.config()