About email images best practices

Learn about best practices when using images in Klaviyo emails, including size recommendations and how to add images.

Best practices for using images in emails

Consider the following when creating images for use in emails:

• Klaviyo supports JPEG, PNG, and GIF image files. You can also upload a WebP file and opt to have Klaviyo automatically convert it to a PNG file for you. In general, PNG files will display best across devices, particularly for images that contain text.
• The maximum image file size supported by Klaviyo is 10MB. However, we recommend using images that are 1MB or smaller, as larger images can load slowly, leading to a poor recipient experience. Klaviyo's built-in image compression tool can help with reducing file sizes for uploaded images without significantly harming quality.
• Choose image dimensions in pixels based on the size you want to display in your email. Try to keep your images between 600 and 1000 px in width and less than 2000px in height for full-width images, in order to balance image quality and loading speeds. Images that are less than the full width of the email can be smaller than 600px.
• Reducing an image's pixel dimensions too far may make it visibly blurry or low quality. When choosing images to use in your messages, consider the tradeoff between image quality and load time: large images may not appear immediately when someone opens your email, especially if they have a slow internet connection.
• Always add alt text to your images. Some inboxes, including Outlook and Apple Mail, can block images depending on the recipient's settings. Including alt text helps recipients using these inboxes to understand what an image is meant to convey, and also supports accessibility.

Insert an image block

To add an image into a template:

1. Drag an Image block into the preview canvas.

2. Once you place the image block, you'll be prompted to add your image by:

• Dropping one or more images into the block to upload
• Browsing your computer to find and upload one or more images
• Importing from a URL
• Choosing an image from your image library
• Choosing an image from your product catalog (if you are integrated with an ecommerce platform or have synced a custom catalog)
• Inserting a dynamic image URL or variable from profile data in a campaign or flow, or from the triggering event in a metric-triggered flow

If you are uploading an image, the maximum image size you can upload is 10 MB.

Automatic image file compression

Klaviyo includes an automatic image compression tool as part of the image upload process to help you balance image clarity with fast load times. Note that this feature isn't supported for GIFs.

With Compare selected in Upload settings, uploading an image opens Select upload version, where you can compare your original file with a compressed version. Each preview shows the file size, along with the percentage difference between them. Select Original or Compressed above each preview to choose which version to upload. Klaviyo adds a Recommended badge on its suggested choice. However, you can override this if you notice a loss of clarity in the compressed version, which can happen with smaller original files.

The first image comparison panel is open by default. For additional images, the panel is closed by default when the original is recommended. If you uploaded multiple images at once, review and choose your preferred option for each image individually.

Click Upload for 1 image or Upload all for multiple images to finish uploading your selections.

Upload settings

If you want to skip the review step when uploading images, adjust your Upload settings. When you upload an image, you'll see an Upload settings button.

Your choice here saves for future uploads. You can select:

• Compare (default): Review and choose between original and compressed versions.
• Use originals: Always upload your original files; no review step.
• Use compressed: Always upload Klaviyo's auto-compressed version; no review step.

Select your preference, then click Back to return to the upload window.

Crop an image

Images in image blocks, split blocks, and table blocks can easily be cropped. Dynamic images cannot be cropped in the editor.

1. Click the image block.
2. Click Crop underneath the image icon on the left.
   
   You can choose to crop an image into a circle, a square, or a rectangle with a custom width and height. When you crop an image within the editor, the full image is preserved, meaning you can adjust or remove the cropping at any time.

3. When you finish cropping, click the back arrow to apply your changes.
   

Resize an image

To resize an image, use the resize sliders in the canvas.

Images in uploaded HTML templates

For HTML templates that reference local image files, upload a ZIP file containing those images during the import process. Match the filenames and folder paths in the ZIP to the references in your HTML. Images referenced by a public URL don't need to be included in the ZIP.

For imported Mailchimp templates, Klaviyo automatically copies images hosted at gallery.mailchimp.com. Images hosted at other URLs remain linked to their original location, so keep those images publicly available or upload them to Klaviyo and update the URLs in your template.

In the HTML editor, place your cursor where the image URL belongs in an <img> tag (inside the src quotes), then click Insert image to upload or choose an image. Selecting an image inserts its URL at the cursor; it does not insert a complete image tag.

Image quality

If you are concerned that your images are not rendering as cleanly or crisply in your templates as you'd like, you can take steps to improve image quality.

One of the prevailing standards for improving the crispness of a rendered image in an email is to insert an image 2x the desired size and then reduce the image size in your template. There are two ways to approach this:

1. Insert a large, crisp version of your image into your template, then select its image block. Under Image layout, set Width to half the uploaded image's pixel width (e.g., 300 px for a 600 px-wide image).
2. Insert a natively larger image (i.e. 600px wide) and display at a smaller size (i.e. 300px width) using CSS; to take this approach, you'll need to insert your image into a dedicated HTML block and adjust the CSS directly

Image types

Klaviyo supports the following image types: JPEG, PNG, and GIF.

You can upload WebP files, and use Klaviyo's built-in converter to convert them to PNG files. However, conversion is not supported for animated WebP files.

If you have other file formats like PSD or SVG, you will need to convert them to a supported image type before uploading.

Learn more about which image types are the best for your email.

The image library

Images you upload to Klaviyo are stored under Content > Media & brand > Images. Deleting an image from your image library will not remove the image from any templates where it is currently used.

Additional resources