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What Are the Best Image File Sizes for Emails?

If you want to add images to your email marketing campaigns, it’s important to understand the proper use of file sizes to ensure clear images. Here’s how.

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What Are the Best Image Files Sizes for Emails

In the world of email marketing, visuals play a crucial role in capturing the attention of subscribers and conveying your message effectively. However, one aspect that often gets overlooked is the file size of the images used in email campaigns. Choosing optimal image file sizes are essential to:

  • Ensure fast-loading emails
  • Maintain high deliverability rates
  • Provide a seamless user experience

Let’s take a look at the best practices for determining the ideal image file size for your email marketing campaigns.

Optimal File Size Range

To strike a balance between image quality and loading speed, it is recommended to keep image file sizes within the range of 100KB to 200KB. This size range allows for fast-loading emails, while maintaining acceptable image quality.

Considerations for Image File Size

Here are the key factors to evaluate and work your file size around:

  • Loading Speed: Large image files can significantly slow down the loading time of emails. With attention spans growing shorter, it is important to optimize the loading speed to avoid losing your recipients’ interest.
  • Email Deliverability: Some email clients or providers may block or mark emails as spam if they contain large attachments. To prevent your emails from being filtered out, keep image file sizes within the recommended range. This ensures your messages reach the recipients’ inboxes.
  • Mobile Optimization: With a significant portion of email opens happening on mobile devices, it is vital to optimize your images for smaller screens and slower internet connections. Smaller image file sizes are critical for quick loading on mobile devices, guaranteeing a smooth and enjoyable experience for your subscribers.

Recommended File Format

When it comes to images, there are two different file types you can include in your email:

  • JPEG: JPEG files are ideal for photographs and images with many colors. They employ compression techniques that reduce file size without compromising image quality. Because they are compressed, they don’t take up much space and are perfect if you’re worried about image loading times.
  • PNG: PNG files are suitable for logos, icons, and images with transparency. They are much higher quality than JPEG, so keep in mind that PNG files may result in larger file sizes compared to JPEG. Consider the type of image and its purpose before choosing between JPEG and PNG formats.

Compression Techniques

Compression refers to the process of reducing the file size of an image without significantly degrading its visual quality. If you want to further optimize image file sizes, consider the following techniques:

  • Image Resizing: Scale down images to the desired dimensions before inserting them into emails. By using HTML or CSS to adjust the image size, instead of relying solely on the image file, you can reduce file size without sacrificing visual quality.
  • Lossy Compression: This technique involves reducing file size by sacrificing some image quality. It’s essential to strike a balance between compression level and image clarity. Experiment with different compression settings to find the optimal trade-off between file size and visual appeal.
  • Online Compression Tools: Numerous online tools are available to compress images without significant quality loss. Services like TinyPNG,, and JPEGmini can help reduce file sizes while maintaining reasonable image quality. Explore these tools to streamline your image compression process.


Optimizing image file sizes can help you create successful email marketing campaigns. Follow the best practices outlined in this article, and you can ensure fast-loading emails, maintain high deliverability rates, and create a positive user experience for your subscribers.


Experiment with different file sizes, compression techniques, and file formats to find the perfect balance that suits your target audience and aligns with your email marketing goals. A well-optimized visual experience can make a significant difference in the success of your email campaigns.

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