viewport

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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 between 20 and 3000).

height (Number)

Height of viewport in pixels (must be between 20 and 3000).

preset (String)

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

Preset width height
macbook-15 1440 900
macbook-13 1280 800
macbook-11 1366 768
ipad-2 768 1024
ipad-mini 768 1024
iphone-6+ 414 736
iphone-6 375 667
iphone-5 320 568
iphone-4 320 480
iphone-3 320 480

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().

Option Default Description
log true Displays the command in the Command log

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

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

  context('iphone-5 resolution', function () {
    beforeEach(function () {
      // 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', function () {
      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')
    })
  })
})

Command Log of multiple viewports

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

This is something Cypress will eventually do, which will match how Chrome’s responsive mobile browsing simulation works. Open an issue if you need this to be fixed.

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 cypress.json:

{
  "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.

Rules

Requirements

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

Assertions

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

Timeouts

  • cy.viewport() can not 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:

Command Log viewport

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

Console log viewport

See also