Images in email best practices: Best sizes and how to embed

Reading Time: 11 minutes

Email images are a powerful tool for capturing attention, reinforcing your message, and driving engagement. Clear visuals can significantly increase open rates, click-throughs, and overall campaign performance. 

But remember, you can’t just add images in emails and call it a day. Using the wrong sizes, poor formatting, or incorrect embedding methods can slow load times, break layouts, or even cause deliverability issues.

The correct email graphic size and formats cut down load time, while proper alignment and spacing keep content readable and focused.

In this article, we’ll list down the best email image practices you can implement and explain how to embed images. We’ll also tell you the right size for email images, the best format, and personalization strategies.

Best practices for using images in emails

As you plan your email marketing campaign, familiarize yourself with best practices for using images in emails. Sticking to them will help you keep your emails looking professional and appealing to your readers. 

Here are the top things you need to know about using images in your emails:

• Ensure image quality: Always use high-resolution images that align with your email’s message. Poor-quality or pixelated visuals can harm credibility, while crisp, clear images increase engagement. Simple refinements through AI image editing can help maintain visual consistency.
• Pick an optimal image file size: To optimize load time and deliverability, keep image file sizes under 100KB. Larger email images can slow down email load times, leading to frustration and reduced engagement.

• Use alt text description: Use descriptive and relevant alt text for each image to ensure accessibility for visually impaired users. Alt text also helps when images don’t load properly.
• Optimize email images for all devices: Many people read emails on their phones, but desktop or tablet users shouldn’t be forgotten. Ensure you optimize the images in your emails to appear as intended, no matter which device the recipient views the content on. Using responsive email templates will ensure your emails look their best.
• Always consider the text-to-image ratio: Avoid using too many images compared to text, as this is one of the spam filter triggers. A good rule of thumb is a 60:40 text-to-image ratio. Too many images or too little text may mean your emails end up in the spam folder. 
• Select the right image format: Stick to standard image formats like JPEG, PNG, and GIF. JPEGs work well for photos, while PNGs are ideal for images with transparent backgrounds. GIFs can add a fun, interactive element, but should be used sparingly.
• Maintain an overall consistency: Each email you send should reflect a cohesive style. While layouts may vary, design elements such as image styles, colors, header sizes, and email fonts should remain consistent to reinforce your brand identity.
• Use multiple images carefully: Using numerous images can work well if each supports the main message and adds value. Space images properly and pair them with text to help readers stay focused.
• Avoid image-only emails: Emails should always include readable text to explain the message clearly. Some email clients block images by default, which can leave image-only emails blank and increase spam filtering or delivery problems.

How to embed images into an email

Now that you have your beautiful images ready, it’s time to add them to your email. This is called embedding. Knowing how to do it correctly will save you from headaches. 

Let’s take a look at how to embed images in emails for popular email providers like Gmail and Outlook. We’ll also guide you on how to do it with Omnisend’s email builder. 

Embedding email images with Gmail

Follow these steps to embed an image directly into a Gmail email:

1. Open your Gmail account
2. Click on the Compose button on the upper left side of the screen
3. Click on the Insert Photo button at the bottom of the message window (it looks like a box with hills)
4. From the Insert Photo page, select the photo you want to use by clicking the Upload option or Web Address (URL) to use an image from the internet
5. Make sure you have your cursor where you want your image to appear in the email, then click on Insert at the bottom of the screen after the photo is uploaded
6. To resize your image, click on it and use the boxes to shrink or expand it. You can edit the alt text by clicking the option at the bottom of the selected image

Embedding email images with Outlook

Follow these steps if you want to embed an email image in an Outlook email:

1. Open your Outlook email 
2. Click on the New Mail option from the left corner
3. Place your cursor in the email section where you want your image to appear
4. Click on the Insert button in the toolbar at the top of the new email
5. Choose Pictures from the menu
6. Select photos from This Device, Stock Images, or Online Pictures
7. Once you have your image, click Open
8. Resize the image as necessary using the boxes in the corners

Embedding email images with Omnisend

Here’s how to embed images or GIFs in your emails with Omnisend:

1. Open your Omnisend account, start a new email campaign, and select your preferred email template
2. Once you’re in the email builder, click on the Quick Add button at the top of your library
3. Drag the image element to where you want the image or GIF to appear in the email
4. Click Select File on the right side of the screen to choose the GIF or image you want to add
5. Choose whether to upload an image from your device or get one from the internet using a URL
6. Insert the image, and you’re all set

What is the best image size for email?

Are you wondering, “What size should email images be?” Although the ideal email marketing image size for email can vary, there are guidelines to help you keep them looking crisp and clear on any device. Choose high-quality images that align with your brand and maintain consistency across your emails.

Consider the type of image you’re including in your email. Is the image in square, landscape, or portrait aspect ratio, and is it a product image, header, or infographic? This affects how the image loads and appears on the screen. 

Here are some general recommendations:

• Full-width header images: The ideal size would be 600-650 pixels wide and 200-300 pixels high. This ensures the image looks great across devices.
• Smaller in-body or product images: The recommended size would be 300-400 pixels wide and 200-300 pixels high. These images should support your main message without dominating the layout.
• Thumbnail images: Opt for 100-200 pixels wide and 100-200 pixels high for small images or icons. They work well for previews without taking up much space.
• Aspect ratio considerations: Stick to an aspect ratio of 16:9 or 4:3. This will avoid images looking stretched or squished.
• Mobile optimization: Make sure your email images look good on mobile screens (about 320–480 pixels wide). This keeps them responsive and user-friendly on small screens.
• Email signature images: Images for email signatures should be small, lightweight, and have limited height and width. This ensures that the image appears with the signature and doesn’t take up too much space.

It might take a few tries to figure out how to embed an image in an email the right way, especially in terms of sizes. However, once you dial it in, you can use the same template to ensure your email images are appealing and your emails get high engagement rates.

Image size for email signature

Since we’re on the topic of images in emails, you may also want to add one to your signature.

Incorporating an image into your email signature can add a unique touch to your messages without detracting from the overall content. However, if the image is too large or too small, it can appear unprofessional and messy. Since most users read emails on their phones, it’s essential that email marketing pictures display well on all devices.

Email services respond to oversized images in a variety of unpredictable ways. For example, they might shrink the image to the dimensions of the screen. They may also shrink the entire email or expand the message so that users can scroll across the image. With that in mind, your signature needs to fit the dimensions of each screen.

If you want an image in your email signature, try to keep it as small as possible. While there isn’t a strict rule for image size in email signatures, it’s best to use images that are no more than 150 pixels tall and 300 pixels wide.

What is the best image format for email?

Choosing the right image format can significantly impact your email’s appearance and performance. Let’s break down the most common formats:

JPG format

JPG (or JPEG) is a great choice for photos and colorful images. It uses lossy compression, which reduces the file size while still maintaining good quality. On the downside, they don’t support transparency, and the quality might decrease slightly if you edit them too much.

GIF format

GIFs are great for simple graphics, animations, and images with a few colors. They can have transparent backgrounds, but remember, GIFs are limited to 256 colors, so they’re not the best choice for detailed images or photos.

PNG format

PNGs are great because they keep all the details of an image without losing any quality. They also support transparency, making them perfect for logos, icons, and text-heavy images. They work well if you want to maintain high quality in emails, but just a heads-up — they’re usually larger files than JPGs.

Difference between attached vs. embedded images

The primary difference between attached and embedded images in emails is how they’re displayed and accessed. The attached images are sent as separate files along with the email. Recipients must download these attachments to view them, which can be helpful in preserving the original size and quality of the image. Attachments are ideal if you’re sending high-quality photos or documents that the recipient might want to save or print. 

On the other hand, embedded images are part of the email’s HTML code, meaning they pop up automatically in the email body when you open it. This can make the email more visually appealing and engaging without extra steps for the reader. Embedded images are particularly great for marketing emails, newsletters, or when you want to grab attention right away.

But there are some downsides — embedded images can make the email larger, which might slow down load times and affect delivery. Plus, some email clients block them by default for security, so the recipient might have to turn them on manually. Knowing these differences can help you decide which method to use based on what you’re trying to achieve and what the reader might prefer.

Personalizing images for email marketing

Personalizing email marketing images can significantly enhance your connection with subscribers. By tailoring visuals to individual preferences, you can create memorable experiences that increase engagement and drive conversions. 

Here are some essential tips for effectively personalizing images in your email campaigns:

Use names in images

Incorporating the recipient’s name into images is one of the easiest ways to personalize email marketing. This simple touch can make your communication feel more intimate and engaging, surprising readers with a level of personalization they might not expect from a marketing email. Services like NiftyImages allow you to seamlessly add names to images.

Customize location-based content

If your goal is to encourage readers to visit a physical store, consider sending them a custom map that highlights the nearest location based on their geographic data. This strategy not only provides valuable information but also emphasizes your brand’s commitment to serving the local community. Personalizing content in this way can lead to increased foot traffic and stronger customer relationships.

Tailor product recommendations

Leveraging a recipient’s purchase history or browsing behavior can enhance the relevance of your email marketing. By showcasing products that align with their interests, you can increase the likelihood of conversions. Automated product recommendation emails can highlight items that the recipient may have previously shown interest in while also suggesting alternative options. This approach not only boosts sales but also demonstrates an understanding of customer preferences.

This email does a great job of highlighting tailored product recommendations by curating a “Picked Just For You” section. Instead of overwhelming the reader, this section presents a focused selection of products aligned with the reader’s preferences for easier decision-making:

Utilize automation tools

Take advantage of automation tools like Omnisend to streamline the creation of personalized images for email campaigns. Features like the Product Recommender allow you to automate the tedious work of generating tailored product suggestions, making it easier to engage your audience.

Additionally, Omnisend’s Brand Assets feature lets you import your brand’s logos, colors, and fonts. This ensures consistency in your marketing materials while saving you time and effort.

By implementing these strategies, you can improve your email marketing campaigns by creating more personalized experiences for your subscribers. This results in higher engagement and loyalty.

Do emails with images perform better?

Emails with graphics have higher average open and click-through rates of 43.12% and 4.84%, respectively. Visuals grab attention, make the content more fun and easy to understand, and help get messages across quickly. 

Just keep in mind that it’s important to strike a good balance between email images and text by using the 60/40 rule.

Each email must contain about 60% text and 40% images. This ratio keeps messages readable while lowering spam risk. Readers get context from text, while images draw attention and reinforce the message.

Why you should never send image-only emails

Sending emails that only contain images might seem visually appealing, but it comes with significant drawbacks that can harm your email deliverability and user experience.

Deliverability issues

Many email clients are cautious with image-only emails, often flagging them as spam. This is because image-heavy or image-only emails are commonly associated with promotional content, which spam filters are designed to catch. 

As a result, your emails may end up in the spam folder, severely limiting their reach. For better results, it’s crucial to maintain a balance between text and images in email marketing.

User experience

Not all users will have images automatically enabled in their email settings. Some email clients block images by default, which means recipients may only see a blank email, so your message gets lost entirely.

Additionally, image-only emails may not be accessible for visually impaired users who rely on screen readers. Since these tools can’t interpret images, they won’t be able to convey your message unless alt text is included, and let’s face it — you can’t fit an entire email message just in the alt text. 

A balanced mix of text and images ensures your email is readable and accessible to all users, improving engagement and conversion rates.

Final thoughts on using images in email

Email images play a crucial role in performance, as they help create first impressions and make messages easier to understand. When sized, formatted, and embedded correctly, they improve readability and help emails avoid spam filters.

Best practices, such as using high-quality visuals and maintaining a proper text-to-image balance, enhance deliverability and accessibility. 

Start incorporating these tips into your emails for better results.

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