Is Embedding Images with Data: URLs Always a Good Idea?

Embedding Images in CSS or HTML via Data: URLs: A Comprehensive Analysis

Introduction

Embedding small images within CSS or HTML as data: URLs has become a common practice to optimize performance by reducing the number of server requests. However, there are several considerations to weigh before implementing this approach.

Question: Is Embedding Images Using Data: URLs a Sound Practice?

Answer:

Embedding images as data: URLs can be a viable option in specific scenarios:

• When dealing with very small CSS images (typically used as sprites) that will be used frequently.
• When IE compatibility is not a concern.
• When minimizing server requests is paramount.

Downsides to Consider:

However, this approach has notable drawbacks:

• It is incompatible with IE6 and 7.
• IE8 supports it only for images up to 32k in size after base64 encoding.
• It increases the size of the HTML page, as the images are loaded every time instead of being cached.
• Base64 encoding adds a 33% overhead to image sizes.
• It can strain server resources when served in gzipped resources, as image compression is computationally intensive.

Bonus Question: Can CSS & JS Also Be Embedded Using Data: URLs?

Answer:

While it is possible to embed CSS and JS as data: URLs, it is generally not recommended due to the drawbacks mentioned above, such as increased page size and reduced cacheability.

The above is the detailed content of Is Embedding Images with Data: URLs Always a Good Idea?. For more information, please follow other related articles on the PHP Chinese website!