What does embedding an image in an email mean?
Embedding an image in emails means including images in the email body and making them appear within the email copy instead of being attached as a separate file.
The embedded email images seamlessly blend with the email content, enhancing the visual appeal and delivering an engaging experience for readers. While there can be many use cases of embedding an image into your email, here are a few that are most common:
To display the product when you’re launching a new product
To display the coupon with coupon code when you’re sending a coupon or offers
To display the banner of the event you’re sending invites to people for
To display testimonials of satisfied clients
The image below shows an email with an embedded image in the email body.
This is different from attaching an image to your email. When you attach the images, the get appear at the bottom of the email and are usually not displayed unless downloaded and viewed separately. Here's what an attached image looks like in an email.
Moreover, you can customize the size of embedded images using content blocks and adding links to images. When used strategically, embedded images make a huge difference in the reading experience.
Which email clients support embedded images?
| Email Client |
Renders Image by Default |
Renders ALT Text |
Renders Styled ALT Text |
| Apple |
Yes |
Yes |
Yes |
| Gmail |
Yes |
Yes |
Yes |
| Outlook |
No |
Yes |
Yes |
| Yahoo |
No |
Yes |
Yes |
How to embed images in an email
Adding images in an email depends on how you create the email. There are four ways to do so. Let’s go through them so you can have your pick:
Coding an email
If you're building an email manually using HTML, you have three main ways to include images: CID Embedding, Inline Embedding, and Linked Images. Each method has its own benefits and limitations.
Here is an in-depth look at each:
CID Image Embedding
CID (Content-ID) embedding involves attaching the image directly to the email and referencing it in your HTML using a unique content ID. It’s a common method when sending emails through traditional SMTP servers.
Pros:
It works offline as the image is already included in the email
You don’t need to upload or host the image elsewhere
It's less likely to be blocked by network firewalls
Cons:
It can make your email size much larger
Not all email clients support it (especially Gmail and some webmail apps)
Some spam filters might remove the attached image automatically
Inline Image Embedding (Base64)
Inline embedding encodes the image into Base64 format and embeds it directly in the HTML. This means the entire image data lives inside your code.
Pros:
You don’t need an image server or host; everything’s in the code
Great for small images like icons or logos
It’s easy to include right in your HTML
Cons:
It can increase your email size quickly, especially with big images
Emails might load more slowly because of the heavy code
Spam filters are more likely to flag or block it
Not ideal if you're using multiple images or large visuals
Linked images
Linked images aren’t embedded in your email’s HTML. Instead, they’re hosted externally on your server, content delivery network (CDN), or image hosting platform and referenced using a standard image URL in the tag.
Pros:
Keeps your email size small and lightweight
Easy to manage and update (just change the image on the server)
Universally supported by all email clients
Ideal for campaigns with multiple or large images
Cons:
Requires an internet connection to load
If the server goes down or the image is deleted, it won’t display
Privacy-conscious users or firewalls may prevent images from loading
3. Using a template builder
Many email marketing platforms provide user-friendly interfaces that allow you to embed images effortlessly without writing any HTML code. We’ve taken an example of Mailmodo that offers a drag-and-drop template builder and shown you how you can do it:
Step 1: Click on Create new template.
Step 2: Click on Start from scratch.
Step 3: Go to Quick Add and drag the image block and drop it in the email template.
Step 4: Select the desired option to add an image. You can choose to upload the image from your computer, add it from the gallery, fetch the image from a URL, get stock images, or get GIFs and stickers.
When you choose to insert an image from a URL, you can opt for the dynamic URL option and specify a personalization parameter. In this field, enter the corresponding column header from your contact list, which will be used to extract the relevant image URL for each receiver.
Step 5: Select the image that you want to upload and click on Insert.
You can customize the image by adding ALT text, borders, linking image to URL, changing alignment and aspect ratio. Once done, click save and your image will be added to your email body.
Try Mailmodo’s Template Builder Today
4. Using email clients
Email clients such as Gmail and Outlook offer user-friendly options to embed images. Here’s how you can do it on Gmail.
Step 1: Click on the Compose button in your Gmail account.
Step 2: Click on Insert photo icon.
The Insert Photo dialog box appears. It gives you 4 options to add images - Photos, Album, Upload, and Web Address (URL).
Step 3: Choose the photos that you want to upload. Select the inline options and click on Insert.
The image will be added inline to the email body.
4 best practices for embedding images in emails
Since not all email service providers display every image format, picking the right format is essential. Ideally, you want to use an image format that is:
For most emails, JPEG, PNG, and GIF are your safest options. These formats are supported by nearly all major email services like Gmail, Outlook, and Apple Mail.
For example, a sales rep sending a product promo to Gmail users might include a PNG image, which works perfectly and instantly. But if they had used a PSD file (a Photoshop format), it might not display at all or worse, cause the email to be flagged as spam.
2. Keep file sizes small
Your image size can impact not only how your email looks but also how well it performs. If the image is too big, it can break the layout of your email or take too long to load. If it’s too small, it may look blurry, especially on high-definition screens.
Ideally, you want your images to be:
Small in file size but still maintains it quality
Scaled to fit both desktop and mobile screens
Stay under spam filter limits
A good rule of thumb is to keep image widths around 600 pixels for desktop and 320 pixels for mobile. You can use tools like TinyJPG or Photoshop, which compress your image without making it blurry.
Apple, for example, often includes clean product images in emails. These visuals are well-compressed, beautifully sharp, and perfectly sized so they don’t slow down the message or break the experience.
3. Add Alt text
Sometimes email services block images by default despite the best practices. Other times, a recipient might be using a screen reader or a slow internet connection. That’s where alt text comes in. It’s a simple line of text that shows up in place of the image and explains what the reader should be seeing.
Quality alt text is made up of:
A short and clear description that explains the purpose of the image
No extra words like “image of” or “photo of”, just the essential information.
Thoughtful use of keywords when relevant, without stuffing them in.
4. Always test your emails
Even if your email looks perfect in your editor, different devices might show it differently. A test helps you catch broken images, weird formatting, or delivery issues before your audience sees them.
Ideally, your testing process should include:
Testing across multiple email platforms and devices.
Checking load times for all images.
Make sure your message is clear, even if images don’t appear.
Using tools that detect technical issues before you send.
Conclusion
Embedding images in emails works better than simply attaching images. Test and find out which techniques work best for your email marketing campaigns. Ensure the images are in the right format and compatible with various email clients. Following the above-mentioned methods of embedding images can make your emails look great and noticeable and increase your engagement rates. It also adds to the overall design of your email and helps you stand out from the competition.
If you want to learn more about designing better emails, check out our resource below.
