Linked Image

Linked image refers to an image that is embedded in a web page or application but is hosted externally or stored in a separate location, typically a different server or URL. Instead of being directly uploaded or embedded into the page’s code, a linked image is referenced by a hyperlink or URL, which allows the page to load the image from an external source when accessed.

In the context of software testing, verifying linked images is essential to ensure that they load correctly, are displayed as expected, and contribute to the overall user experience. Testing linked images includes checking for broken links, verifying proper display, and ensuring that the images are responsive across different devices and screen sizes.

Types of Linked Images:

• External Linked Images:
  These are images hosted on an external server or third-party service, such as a cloud-based image storage service or a CDN. The web page or application references the image via an absolute URL (e.g., https://example.com/images/photo.jpg).
• Relative Linked Images:
  These images are stored within the same domain or project but are referenced using a relative path. For example, the link may look like /images/photo.jpg, indicating the image is located in a specific directory within the project’s folder structure.
• Dynamic Linked Images:
  Dynamic linked images are those whose URL or source may change based on user input, session data, or other factors. These links might reference images that are generated dynamically or serve personalized content (e.g., a user’s profile picture).
• Embedded Linked Images:
  These images are embedded into the HTML code but reference an external source for their actual content. For example, an image could be embedded as a link that pulls its source from a remote URL rather than being stored directly within the project.

Strategies for Testing Linked Images:

1. Manual Link Checking:
   Testers can manually check the URLs of linked images to ensure they are correct and lead to the right destination. This involves clicking on the links or using browser developer tools to verify the image source.
2. Automated Link Checking:
   Tools such as Screaming Frog or Xenu Link Sleuth can automatically scan a website or application for broken links, including linked images. These tools help identify any missing or broken image links that may need to be fixed.
3. Cross-Browser and Cross-Device Testing:
   Linked images should be tested across multiple browsers and devices to ensure they load correctly in all environments. Tools like BrowserStack or Sauce Labs can simulate different browsers and devices to test the image rendering behavior.
4. Image Optimization Testing:
   Testers should verify that linked images are optimized for fast loading. This involves checking the image file sizes, formats, and compression levels to ensure they do not slow down the page. Tools like Google PageSpeed Insights or Lighthouse can help assess image performance.
5. Accessibility Testing:
   Linked images should be tested for accessibility compliance, ensuring they have proper alt text, titles, and descriptions. Tools like Axe or WAVE can help identify accessibility issues related to linked images.
6. Security Testing:
   Ensure that the external servers hosting linked images are secure and that the images themselves do not pose any security risks. This includes verifying that the source of the image is trusted and that the image does not contain malicious code or scripts.