Viewport

Examples of changing the size of your application's viewport in Cypress, for a full reference of commands, go to docs.cypress.io

cy.viewport()

To set the viewport size and dimension, use the cy.viewport() command.

const deviceViewports = [
  'macbook-15',
  'macbook-13',
  'macbook-11',
  'ipad-2',
  'ipad-mini',
  'iphone-6+',
  'iphone-6',
  'iphone-5',
  'iphone-4',
  'iphone-3',
]

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.exist')

// instead we have the "hamburger" icon
cy.get('.sidebar-button').should('be.visible').click()
cy.get('.nav-item').find('a').should('be.visible')

// lets see what our app looks like on a super large screen
cy.viewport(2999, 2999)

// Test viewport at different preset widths
deviceViewports.forEach((resolution) => {
  cy.viewport(resolution)
  cy.wait(200)
})

// Test viewport in portrait and landscape orientations
cy.viewport('ipad-2', 'portrait')
cy.wait(200)
cy.viewport('iphone-4', 'landscape')
cy.wait(200)

// The viewport will be reset back to the default dimensions
// in between tests (the default can be set in cypress.json)

Viewport and the config viewport values

<p>Some text</p>

// Cypress.config('viewportWidth') shows the current value
// cy.viewport() does not change it
const w = Cypress.config('viewportWidth')
expect(w, 'initial width').to.be.greaterThan(100)
cy.log('initial', w) // whatever value, probably 600
cy.viewport('ipad-2')
cy.log('still the same', Cypress.config('viewportWidth')) // same value
cy.viewport('iphone-4').then(() => {
  expect(
    Cypress.config('viewportWidth'),
    'after using viewport',
  ).to.equal(w)
})

To know the current viewport, use cy.viewport(w, h) and update the Cypress.config too using cy.then callback to make sure the values are set after the command has changed the viewport.

cy.viewport(1200, 400)
  .then(() => {
    Cypress.config('viewportWidth', 1200)
    Cypress.config('viewportHeight', 400)
  })
  // some time later
  .then(() => {
    cy.log('current width', Cypress.config('viewportWidth'))
  })

You can also get the current resolution from the application's window object.

cy.window().its('innerWidth').should('equal', 1200)