Email Template Size Guide: Width, Height, File Size, and Best Practices

Standard email dimensions overview

Email is a great way to communicate with your customers. However, if you don’t format your emails correctly, they won’t get the attention they deserve. Using the right dimensions ensures that your content is properly aligned and displayed on any device, from smartphones to desktop screens. This improves your audience’s user experience and makes your emails look more professional thanks to improved readability and enhanced visual appeal. 

To understand how it works in more detail, let’s talk numbers. We will consider such parameters as width and height, block sizes, headings, content blocks, etc. Use the table below to quickly determine the ideal newsletter sizes:

In general, the ideal width for email templates is around 600-800 pixels. This allows for a comfortable reading experience on most devices and ensures that your content is not shortened or cut off on smaller screens. However, there is no one “best overall” size for an email, as the appropriate size depends on the specific goals of the campaign and email design.

Best email sizes breakdown

While there is no “perfect” email size, there are some guidelines to help you choose the right fit for your campaign. Here is an optimal email size breakdown, including some of the general dimensions and other important parameters.

Width

The width of an email refers to the horizontal size of the message, which is typically measured in pixels. It has long been believed by marketers that a width of 600 pixels is the optimal size for emails. This was because devices were slower and display resolutions were lower back in the day, so emails wider than 600 pixels could be displayed incorrectly in email clients. 

Today, many marketers believe the ideal width for an email template to be 600-640 px; however, it can reach up to 800 px. If you want to stray from the guidelines, you’ll need to extensively test your custom-sized email on various email clients. If there aren’t any issues, you can go ahead and send it out. However, a 600-640 px still remains the industry standard and is a safer option if you’d rather not spend time on testing. 

For an email to properly render on mobile, prepare a template that is 320 px wide. The maximum width for mobile template versions is 480 px, but readers will have to flip their phone horizontally in that case, which might be inconvenient for them and thus decrease engagement.

When can you go wider than 640 px?

A 600-640 px layout is still the safest range for most campaigns. Wider templates, around 700-800 px, can work for highly visual newsletters, product showcases, or editorial emails, but only after testing in Outlook, Yahoo, Gmail, Apple Mail, and mobile views.

Mobile layouts should not rely on horizontal scrolling. If you use a wider desktop design, create a responsive single-column version for mobile. For sharper visuals, you can prepare retina images at 2x dimensions and display them at the intended width, but keep file weight under control so the email still loads quickly.

The email below from wet n wild has a width of 610 pixels which is a common size for a standard newsletter.

To determine the best width for your email, consider the campaign’s content and the devices your recipients are most likely to use for viewing it. You can also try test sends to different email clients to see if the contents of your messages are properly displayed.

Height

Email height is less restrictive than width options. In fact, it is close to unlimited. The only thing that limits the height of an email template is the file size requirements (we’ll discuss them below): if an email has a lot of content and is very long, its size will be bigger. 

As a rule, the ideal template height is 1500 px — this is enough in most cases and doesn’t require too much scrolling. If necessary, the email can be even longer — up to 3000 px in height or more — to display all the content you want to include. You just need to remember that the longer your email is, the less likely it is to be read to the end. To make sure your recipients see the essential information, place it at the top of the email — preferably, in the 300-500 top pixels (“above the fold”).

If you have a lot of content to include in the email, consider using formatting techniques, such as headings, bullet points, and shorter paragraphs, to make the content easier to scan and read. You can also use images or other visual elements to break up the text and make the email more visually appealing. 

Here’s an email newsletter from Cuyana. Although its height is almost 4000 pixels, it is easy to read thanks to the clear block structure.

Weight

An excessively heavy email may be cut off in email clients. To avoid this issue, keep the HTML weight of your emails within the range of 20-102 KB. The ideal file size is 75 KB. To reduce the overall weight of your emails, avoid including a lot of content. Also note that the HTML weight isn’t connected to the weight of the media (like images or GIFs) in an email. That means compressing an image, for example, won’t change the weight of the email. To reduce it, you’ll need to cut the content of the email itself.

The 102 KB limit refers to the HTML code of the email, not the total weight of externally hosted images. When an HTML message goes over that limit, Gmail may clip the email and hide the rest behind a “View entire message” link. This can also hide the unsubscribe link or tracking-sensitive footer content, so treat 102 KB as a hard ceiling and 75 KB as a safer working target.

To reduce HTML weight, remove unused code, simplify nested sections, reduce repeated inline styles, avoid too many product blocks, host images externally, compress media, and test the final HTML before sending.

For example, this Cartier email weighs 52.74 KB, while its image weight is 3.53 MB, according to MailCharts:

Does your newsletter weigh too much? Consider creating a minimalist email, focusing on the most important information and excluding unnecessary elements. Additionally, avoid adding large attachments to your emails. This can help to keep the size of the email small and make it easier for the reader to understand its contents.

Other important email template dimensions

In addition to the overall dimensions of your email template, there are several other important parts to consider when designing your emails. Check out these marketing email components:

Preview text

An email preview (sometimes called a preheader or a preview text) is a snippet of text that is displayed in an email client or app along with the subject line of an email. This element can typically be instantly seen and is intended to give the reader a taste of the content of the email:

It is a crucial part of your email, as it can entice your audience to open the email and provide a preview of the content inside. The ideal preview length is around 50-100 characters. You can learn about the preview text best practices and examples in our definitive guide. Don’t forget that the preview text you see on desktop computers is shortened on mobiles. So, EmailTooltester has created a great, free tool that lets you test how the preview text looks on different mobile devices.

Some emails can also have a preheader inside the actual message. It shows up on the top of the email template, before the header. It can include the link to view the email in a browser, repeat the preheader shown in the inbox, or contain other information. It’s best to keep the preheader short — not more than 50 to 65 pixels high (or 50-100 characters). The width of the preheader is the same as the width of the email overall. In this example from Moda Operandi the preheader is 38 pixels high:

Header

The email header is the top section of your email, typically containing your logo and other branding elements. The ideal size for the header is around 600-800 pixels (as the rest of your email) in width and around 100-150 pixels in height. The maximum header height is 200 px. Your branding can be shown clearly and prominently without using up a lot of space in the email.

This Columbia email’s header, for example, is 146 pixels high. It stands out thanks to the contrasting deep gray color.

Content blocks

The content blocks are the body of your email, where you include your message, images, and other elements.

To provide the best experience for your audience, make your content blocks brief and useful. Long blocks of content can lead to email abandonment and low email read times, which you want to avoid. Instead, keep each content block around 200-300 pixels in height. The height of your content blocks will vary depending on the amount of content you include, but it is important to keep it within a reasonable range to avoid overwhelming your audience. The total height of all your content blocks should be in the range of 800-1200 pixels.

Let’s examine the content blocks of this Herb & Olive email:

The email has 5 content blocks. The first one measures approximately 47.8 pixels, the other content blocks’ size ranges from 400 to 450 pixels. The total height of all the content blocks (excluding the padding between them) therefore is 1733.8 pixels. 

Footer

The email footer is the bottom section of your email, typically containing your contact information, legal disclaimers, and social media links:

A footer that is too large can make your email difficult to read and navigate. For that reason, a footer size should be around 100 pixels. If you need to have additional elements like website links, keep the total length of the footer at 300 pixels. Your contact information can be displayed clearly and prominently without using up a lot of space in the email. The height of the footer in our example above is 327,4 pixels.

Banner

A banner is a large image or call-to-action (CTA) that is typically placed at the top or bottom of your email. It can also include a short copy and a button:

The recommended email banner size is as wide as the rest of your email (so 600-700 pixels wide for desktops or 320-385 pixels wide for mobile devices) and 90-200 pixels high. In some cases, banners can take up most of the email, so the maximum size can reach 700×1730 px. 

The Lush banner in our example is an image with a slogan and a button. The height of the banner is 650 pixels. Although the recommended size is smaller, this height works because the email is minimalistic and only has one narrow content block beside the banner.

CTA buttons

CTA buttons are used to encourage your audience to take a specific action, such as visiting your website or making a purchase:

The ideal size for CTA buttons is around 200-300 pixels in width and around 50-75 pixels in height. On mobile, though, it’s better for the CTA button to take up the whole width of an email.

Image and GIF size

Images can make emails more visually appealing and interesting. The best size for images in emails is around 600-800 pixels wide, so they look clear and high-quality on most devices; if you are adapting product photos or campaign visuals, checking standard photo sizes can also help keep proportions consistent before resizing them for email. You should also compress images to make them smaller and make the email load faster. The ideal image file size is 200 KB and the maximum is 1 MB.

If you’re working with brand assets or brochures in PDF format, a quick way to prepare visuals for email is to convert them into images first.

For the GIFs, aim for 500 KB and don’t exceed 1 MB. Remember that the heavier the GIF, the longer it takes to load.

What about transactional emails’ size?

Marketing emails are used to advertise products or services and try to convince the recipient to do something.

Transactional emails provide information tied to a specific user action, such as instructions or confirmation of an action. These emails are usually shorter and focused on providing information. They can include some marketing material, but their main purpose is to build trust with the recipient.

Here’s an example of a transactional email:

From: ILIA 

Subject: From the desk of Sasha Plavsic…

This email is visibly shorter than the marketing ones. Its height is only 813 pixels. When preparing transactional messages, opt for conciseness and try not to exceed 1500 pixels.

How to set email template sizes with Selzy?

Now, let’s take a look at how you can easily set email template sizes using email marketing software. Selzy is an email service provider with a free version and affordable pricing plans that has a tool for creating unique email templates with no coding skills required. What is more, it offers 150+ free templates and beginner-friendly yet powerful email editing capabilities including an AI assistant. 

To set the size of an email template using Selzy’s email builder, follow these steps:

• Log in to your Selzy account and click on the “Create campaign” button from the main menu on the left. If you are not registered yet, you’ll need to sign up first.

• Choose from dozens of ready-made templates or create your own from scratch.

• In the email builder, you can use the “Settings” tab on the right-hand side to set the overall size of your email template.

• You can also adjust the width of each separate element of the template:

• All pre-made templates in Selzy, however, already have the ideal width of 640 pixels. If you don’t feel like experimenting with email marketing campaigns, you can go with the default settings and get your message ready in mere minutes. In case you need more detailed instructions, we have complete guides on designing email in the editor and setting the width of the template too. 
• You can also use the layout options to set the size of individual content blocks within the email template. Set the width of an image block to a specific size, or use a percentage to make it responsive to the size of the screen. In the editor, it’s possible to switch between the desktop and mobile views of the email with a click.
• When you are finished setting the sizes of your email template, click the “Save” button to save your changes. After sending the campaign, you can use it as a template for future sendings. It’s also possible to prepare the template in advance without sending the email.

• With Selzy’s intuitive email builder you can design your campaigns with ease or choose from expertly made templates for different occasions. Not only that, but the platform also boasts a wide range of features for all things email marketing, such as email automation, analytics, A/B testing, and more — plus you can try it out for free.

Conclusion

Let’s sum things up.

Since it is crucial to strike a balance between providing all the necessary marketing information and keeping the email small enough, you should also remember these tips:

• Optimize the size of your email template to ensure that your content looks good on any device.

• Avoid adding large attachments to your emails if possible.
• Design and structure the emails purposefully.
• Try using Selzy’s easy no-code email builder for your next email campaign.

Want to revisit our template sizes table? Click on this link for a quick redirect!