Full page screenshot in Selenium Python - Build an Automation Script

Capture full page screenshot of a webpage

Preconditions (3)

Step 1: Open the browser using Selenium WebDriver

Step 2: Navigate to the target webpage URL (e.g., https://example.com)

Step 3: Wait until the page is fully loaded

Step 4: Capture a full page screenshot

Step 5: Save the screenshot to a file named 'full_page_screenshot.png'

Step 6: Close the browser

✅ Expected Result: A file named 'full_page_screenshot.png' is saved containing the full visible content of the webpage

Automation Requirements - Selenium with Python

Assertions Needed:

Verify the screenshot file 'full_page_screenshot.png' exists after test execution

Verify the screenshot file size is greater than zero bytes

Best Practices:

Use explicit waits to ensure the page is fully loaded before taking the screenshot

Use Selenium's full page screenshot capability (e.g., Chrome DevTools protocol or Firefox full page screenshot)

Handle browser setup and teardown properly

Use clear and maintainable locators if needed

Automated Solution

Selenium Python

import os
import time
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By

# Setup Chrome options for headless mode (optional)
chrome_options = Options()
chrome_options.add_argument('--headless=new')
chrome_options.add_argument('--window-size=1920,1080')

# Setup Chrome driver service
service = Service()
driver = webdriver.Chrome(service=service, options=chrome_options)

try:
    # Navigate to the webpage
    driver.get('https://example.com')

    # Wait until the body element is present to ensure page load
    WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.TAG_NAME, 'body')))

    # Pause briefly to allow any dynamic content to load
    time.sleep(1)

    # Take full page screenshot (works in Chrome 59+)
    screenshot_path = 'full_page_screenshot.png'
    driver.get_full_page_screenshot_as_file(screenshot_path)

    # Assertions
    assert os.path.exists(screenshot_path), f"Screenshot file {screenshot_path} does not exist"
    assert os.path.getsize(screenshot_path) > 0, "Screenshot file is empty"

finally:
    driver.quit()

This script uses Selenium WebDriver with Chrome in headless mode to open the webpage https://example.com. It waits explicitly for the <body> tag to be present, ensuring the page is loaded. Then it pauses briefly to allow dynamic content to settle.

The key method get_full_page_screenshot_as_file() captures the entire page, not just the visible viewport. The screenshot is saved as full_page_screenshot.png.

After taking the screenshot, the script asserts that the file exists and is not empty, confirming the screenshot was successfully saved.

Finally, the browser is closed properly in the finally block to avoid resource leaks.

Common Mistakes - 4 Pitfalls

Using driver.save_screenshot() which captures only the visible viewport

Not waiting for the page to load before taking the screenshot

Not closing the browser after the test

Hardcoding sleep times without explicit waits

Bonus Challenge

Now add data-driven testing to capture full page screenshots of three different URLs

Show Hint

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