Screenshots Ruby Tutorial

The Applitools Eyes Screenshot Ruby SDK allows you to easily add visual checkpoints to your Ruby images tests. It takes care of images given by the user, sending them to the Eyes server for validation and failing the test in case differences are found.

Install the SDK

gem install eyes_images

Run your first test

Applitools Eyes reports differences by comparing screenshots of your application with baseline images that define the expected appearance of the application at each step of the test. The user should specify the environment (OS and application under test), and the Eyes SDK will automatically set the viewport size based of the size of the image being tested. It will then compare the screenshots against baseline images that are specific to that environment. The first time you run a test in a given environment, its screenshots will be automatically saved as its baseline. Starting from the second run onward, you always have a baseline to compare against.

The test below is a simple Ruby program that visually validates an image from Applitools' homepage. It consists of a single visual checkpoint, The first time you run this test a new baseline will be created, and subsequent test runs will be compared to this baseline. If any screenshot mismatch its baseline image in a perceptible way, eyes.close will throw a DiffsFoundError which includes a URL that points to a detailed report where you can see the detected differences and take appropriate actions such as reporting bugs, updating the baseline and more.

Before running the test, make sure to set the API key that identifies your account in the environment variable APPLITOOLS_API_KEY or directly assign it to the eyes.api_key property. You can find your API key under the user menu located at the right hand side of the test manager toolbar. If you don't yet have an account create it now to obtain your key.

require 'eyes_images'
require 'logger'
require 'open-uri'
require 'chunky_png'

eyes =

# Initialize the eyes SDK and set your private API key.
eyes.api_key = 'YOUR_API_KEY'
eyes.log_handler =
image_url = ''

image_file = open(image_url)
image = ChunkyPNG::Image.from_file(image_file)

eyes.test(app_name: 'Eyes Images SDK', test_name: 'Applitools Hero') do

    # Visual validation.
    eyes.check_image(image_bytes: image.to_blob, tag: "test")

        image_bytes: image.to_blob,
        region:, 175, 465, 75),
        tag: 'Main Text'


Analyze your test results

Congratulations! You've successfully run your first visual UI test with Applitools Eyes! A detailed report is ready for your inspection at the Applitools Eyes test manager. Watch this 5 minute video to get acquainted with the test manager and to learn the basics of baseline maintenance.

Login to Applitools and analyze the results.

Learn more

Applitools Eyes is a powerful platform for automated visual UI testing that supports full page screenshots, page layout matching, cross-device and browser testing, test batching, baseline branching and merging, automated baseline maintenance, collaboration features, and much more. Applitools has over 40 SDKs supporting a broad range of testing environments.

Reference documentation

To learn more, check out the Applitools Eyes documentation and tutorials for other testing environments.

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Last Updated: 11/2/2018, 11:43:49 AM