Full page screenshot in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Selenium Python code snippet?

Consider the following code that attempts to take a full page screenshot using Selenium in Python. What will be the result of running this code?

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless=new')
service = Service()
driver = webdriver.Chrome(service=service, options=options)
driver.get('https://example.com')

# Attempt to take full page screenshot
result = driver.save_screenshot('page.png')
driver.quit()
print(result)

A False (screenshot not saved due to missing permissions)

B True (screenshot saved as 'page.png', but only visible viewport captured)

C Throws an exception because save_screenshot does not exist

D True (full page screenshot saved as 'page.png')

💡 Hint

The save_screenshot method captures only the visible part of the page by default.

The save_screenshot method returns True if the screenshot is saved successfully. However, it captures only the visible viewport, not the full page. To capture the full page, additional steps or tools are needed.

🧠 Conceptual

intermediate

Which Selenium Python approach captures a full page screenshot?

You want to capture a full page screenshot of a webpage using Selenium with Python. Which approach below will correctly capture the entire page, not just the visible viewport?

A Use JavaScript to get page height, resize window, then save_screenshot

B Use driver.execute_script('window.scrollTo(0,0)') then save_screenshot

C Use driver.get_screenshot_as_base64() only

D Use driver.save_screenshot('file.png') directly

💡 Hint

Think about how to make the browser window tall enough to show the entire page.

To capture the full page, you can use JavaScript to get the full page height, resize the browser window to that height, then take a screenshot. This ensures the entire page is visible in the viewport.

🔧 Debug

advanced

Why does this full page screenshot code fail with an error?

This Selenium Python code tries to take a full page screenshot but raises an error. What is the cause?

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.service import Service

service = Service()
driver = webdriver.Chrome(service=service)
driver.get('https://example.com')

height = driver.execute_script('return document.body.scrollHeight')
driver.set_window_size(1200, height)
screenshot = driver.get_screenshot_as_file('fullpage.png')
driver.quit()

A execute_script returns None causing set_window_size to fail

B set_window_size is not a valid method on driver

C get_screenshot_as_file requires a full file path, not just filename

D The window height exceeds maximum allowed size causing error

💡 Hint

Browsers limit window size; very tall sizes cause errors.

Browsers have maximum window size limits. Setting window height to the full page height can exceed this limit and cause errors. You need to handle this by scrolling and stitching screenshots or using browser-specific full page screenshot features.

❓ framework

advanced

Which Selenium WebDriver method supports full page screenshots in recent versions?

Recent Selenium WebDriver versions introduced a method to capture full page screenshots directly. Which method is it?

A driver.get_full_page_screenshot_as_file('file.png')

B driver.full_page_screenshot()

C driver.get_full_page_screenshot_as_base64()

D driver.get_screenshot_as_file('file.png')

💡 Hint

Look for a method returning a base64 string with 'full_page' in its name.

Selenium 4.8+ added get_full_page_screenshot_as_base64() to capture full page screenshots as base64 strings. This method captures the entire page, unlike get_screenshot_as_file which captures only the viewport.

❓ assertion

expert

Which assertion correctly verifies a full page screenshot file exists and is not empty?

After taking a full page screenshot saved as 'fullpage.png', which assertion best confirms the file exists and has content?

A assert os.path.exists('fullpage.png') and os.path.getsize('fullpage.png') > 0

B assert os.path.isfile('fullpage.png') == False

C assert os.path.getsize('fullpage.png') == 0

D assert os.path.exists('fullpage.png') and os.path.getsize('fullpage.png') == 0

💡 Hint

File must exist and have size greater than zero.

To verify a screenshot file is created and not empty, check that the file exists and its size is greater than zero bytes.

Practice

1. What is the main advantage of taking a full page screenshot in Selenium?

easy

A. It speeds up the test execution

B. It only captures the visible part of the webpage

C. It captures the entire webpage, including parts not visible on screen

D. It automatically scrolls the page during testing

Solution

1. Step 1: Understand what a full page screenshot means

   A full page screenshot captures the entire webpage, not just the visible part on the screen.

2. Step 2: Compare options with this definition

   Only It captures the entire webpage, including parts not visible on screen correctly states this advantage. Options B, C, and D describe other unrelated behaviors.

3. Final Answer:

   It captures the entire webpage, including parts not visible on screen -> Option C

4. Quick Check:

   Full page screenshot = entire page capture [OK]

Hint: Full page means entire webpage, not just visible part [OK]

Common Mistakes:

• Confusing full page with visible viewport only
• Thinking it speeds up tests automatically
• Assuming it scrolls the page during capture

2. Which Selenium Python method is used to save a full page screenshot in Firefox?

easy

A. driver.get_screenshot_as_file('file.png')

B. driver.save_full_page_screenshot('file.png')

C. driver.save_screenshot('file.png')

D. driver.take_full_screenshot('file.png')

Solution

1. Step 1: Identify the correct method for full page screenshot in Firefox

   Firefox does not have a built-in method named save_full_page_screenshot. The standard method to save a screenshot is get_screenshot_as_file, which captures the visible viewport.

2. Step 2: Check other options for correctness

   driver.save_full_page_screenshot('file.png') is invalid as save_full_page_screenshot is not a standard Selenium method. driver.save_screenshot('file.png') saves visible viewport screenshot. driver.take_full_screenshot('file.png') is not a valid method.

3. Final Answer:

   driver.get_screenshot_as_file('file.png') -> Option A

4. Quick Check:

   Standard screenshot method = get_screenshot_as_file [OK]

Hint: Use get_screenshot_as_file to save screenshot [OK]

Common Mistakes:

• Using non-existent save_full_page_screenshot method
• Confusing save_screenshot with full page capture
• Trying invalid methods like take_full_screenshot

3. Given this code snippet, what will be the result?

driver.get('https://example.com')
driver.save_full_page_screenshot('page.png')
print('Screenshot saved')

medium

A. Runtime error because get_full_page_screenshot_as_file is unsupported

B. Screenshot saved and full page screenshot saved as 'page.png'

C. Only visible part screenshot saved as 'page.png'

D. SyntaxError due to incorrect method name

Solution

1. Step 1: Analyze the method usage

   The method save_full_page_screenshot is not a valid Selenium WebDriver method and will cause a SyntaxError or AttributeError.

2. Step 2: Check the print statement

   The print statement will not execute because the previous line causes an error.

3. Final Answer:

   SyntaxError due to incorrect method name -> Option D

4. Quick Check:

   Invalid method call causes error [OK]

Hint: Invalid method names cause errors [OK]

Common Mistakes:

• Assuming method is supported causing success
• Confusing full page with visible screenshot
• Thinking method name is correct syntax

4. You wrote this code but get a blank screenshot file:

driver.get('https://example.com')
driver.save_screenshot('screen.png')

What is the likely cause?

medium

A. Page did not fully load before screenshot

B. save_screenshot does not save files

C. Method get_full_page_screenshot_as_file is required instead

D. Screenshot file path is invalid

Solution

1. Step 1: Understand why screenshot is blank

   If the page is not fully loaded, the screenshot may capture a blank or incomplete page.

2. Step 2: Evaluate other options

   save_screenshot does save files. Method get_full_page_screenshot_as_file is unrelated to blank screenshot issue. Invalid file path would cause an error, not a blank file.

3. Final Answer:

   Page did not fully load before screenshot -> Option A

4. Quick Check:

   Wait for page load before screenshot [OK]

Hint: Always wait for page load before screenshot [OK]

Common Mistakes:

• Assuming save_screenshot never saves files
• Confusing full page screenshot with blank image issue
• Ignoring page load timing problems

5. How can you ensure a clean full page screenshot in headless Firefox using Selenium Python?

hard

A. Use save_screenshot immediately after driver.get() without waits

B. Scroll manually and take multiple viewport screenshots

C. Use headless mode, wait for page load, then call save_full_page_screenshot

D. Use driver.execute_script to hide elements before screenshot

Solution

1. Step 1: Understand headless mode limitations

   Headless Firefox does not support a built-in full page screenshot method.

2. Step 2: Use manual scrolling and multiple viewport screenshots

   To capture the full page, scroll manually and stitch multiple viewport screenshots.

3. Final Answer:

   Scroll manually and take multiple viewport screenshots -> Option B

4. Quick Check:

   Manual scroll + multiple screenshots = full page capture [OK]

Hint: Manual scrolling needed for full page in headless Firefox [OK]

Common Mistakes:

• Assuming save_full_page_screenshot exists in headless mode
• Taking screenshot immediately without waiting
• Hiding elements unnecessarily before capture