Mastering Images in Email for Max Engagement

When your customer’s inbox is bursting at the seams, what makes them stop scrolling and actually read your email? More often than not, it’s a brilliant image that catches their eye. Using images in email is about so much more than just making things look nice; it's a smart tactic to get people clicking, build your brand, and ultimately, make more sales.

The Real Impact of Visuals in Your Emails

Take a quick glance at your own inbox. Are you drawn to the wall of plain text, or the email with a sharp, relevant picture that tells a story in an instant? Our brains are wired to process images thousands of times faster than words. For a UK small business fighting for attention, that’s a massive advantage.

An email with thoughtfully chosen images just feels more professional and credible. It breaks up intimidating chunks of text, making your message feel less like a chore and more like a conversation. Good visuals guide your reader's eye straight to the important bits – like that "50% Off" banner or the "Shop Now" button. Without them, an email is just text. With them, it's an experience.

Why Visuals Drive Better Results

This isn't just a gut feeling; the numbers prove that people prefer visuals. For businesses here in the UK, simply adding a relevant graphic can give your campaign a serious lift. Recent research found that a whopping 65% of email readers prefer emails that contain mostly images.

This preference has a direct impact on performance. Emails with images see an average open rate of 21.44%, comfortably beating the 15.02% for text-only versions. This data tells a very clear story for anyone running an email campaign:

• Boosted Engagement: Pictures make your emails more interesting, keeping subscribers reading for longer.
• Clearer Communication: They can show off a product or explain a concept far better than words ever could.
• Stronger Brand Identity: Using consistent imagery helps customers instantly recognise and connect with your business.

From Pretty Pictures to Powerful Performance

At the end of the day, using images is about growing your business. Every single visual you include should have a job to do, whether it’s showing off a new product, announcing a sale, or just building a bit of rapport with your audience.

But here’s the catch: the power of your images hinges on how well they perform technically. To really see the benefits, you need to make sure they don't slow your email down. Understanding the basics of compressing images for faster load times is the first step to ensuring your beautiful emails actually land in the inbox and load in a flash.

Choosing and Preparing Your Email Images

Picking the right image for your email campaign is a bit like dressing a shop window. It needs to stop people in their tracks, show off your brand's personality, and make them want to step inside for a closer look. The truth is, not all visuals are created equal, and the ones you choose should be working hard to meet your campaign's goal.

Think of the different types of images as a toolkit. A brilliant, high-quality photograph is your go-to for showing off a product's finer details. A custom illustration can bring a complex idea to life with a bit of charm. If you're presenting data, nothing beats a well-designed infographic. And for a bit of fun or a quick demo, an animated GIF is a fantastic tool.

Choosing the Right Image Type

Your choice should always be a strategic one. Launching a new dish on your menu? A professional, mouth-watering photo is a no-brainer. Trying to explain a new software feature? A short GIF showing it in action will do a much better job than a dense paragraph of text.

• Photographs: Perfect for product shots, introducing the team, or creating an aspirational vibe. Just make sure they're high-resolution and fit your brand's look and feel.
• Illustrations: A great way to explain abstract concepts, inject some personality, and stand out from competitors who just use stock photos.
• Infographics: The best choice for simplifying complex information, sharing survey results, or walking someone through a process.
• Animated GIFs: Use them to demonstrate how a product works, add a bit of humour, or draw the eye to your all-important call-to-action button.

Before you hit 'send', just double-check that you have the legal right to use your chosen images. Getting caught using copyrighted material without permission can land you in hot water. To get a clear picture of your responsibilities, have a look at our copyright policy page.

Understanding Image File Formats

Once you've got your visual, you need to save it in the right format. For images in email, there are really only three formats you need to know about: JPEG, PNG, and GIF. Each has its own strengths, and picking the right one is crucial for getting that balance between quality and performance just right.

It’s worth noting that simply including images can have a real impact. The average email open rate for UK businesses sits around 16.4%, but this jumps to 21.44% when images are part of the mix. That's a significant lift.

This preference for visual content is something we see all the time. When given the choice, subscribers often lean towards emails with images over text-only versions.

The image above really drives home why getting your head around images is so important for keeping your subscribers engaged.

To help you decide which format to use, here’s a quick rundown of the most common options and what they’re best for.

Comparing Image File Formats for Email Campaigns

File Format	Best For	Pros	Cons
JPEG	High-quality photographs and complex images with many colours.	Excellent compression for small file sizes with minimal quality loss.	Doesn't support transparency. Can look blurry if over-compressed.
PNG	Logos, icons, and graphics that need a transparent background.	Supports transparency and offers "lossless" compression (no quality loss).	File sizes can be much larger than JPEGs, especially for photos.
GIF	Simple animations, basic graphics with limited colours, and short loops.	Supports animation and transparency. Very small file sizes for simple images.	Limited to only 256 colours, which can make photos look poor quality.

Choosing the right format is the first step. For a standard photograph, JPEG is almost always your best bet. It gives you that sweet spot of great quality and a small file size, which is exactly what you need for fast-loading emails.

A Practical Guide to Image Preparation

Getting your images ready before you add them to your email is key. It ensures they look sharp on every device and load in a flash, stopping your subscribers from hitting delete before they've even seen what you have to offer. It all comes down to three simple steps: sizing, compression, and naming.

Step-by-Step Image Optimisation

1. Get the Sizing Right: Before you upload anything, resize your image to the exact width it will be in your email. For most templates, that’s somewhere between 600 and 650 pixels wide. If you upload a giant 4000-pixel image and rely on the email client to shrink it, you’ll kill your load time. A tool like Canva or even the Preview app on a Mac can do this in seconds.
2. Compress Smartly: Once it's the right size, compress the image to shrink its file size without making it look pixelated. A good rule of thumb is to keep each image under 200KB. There are plenty of free online tools like TinyPNG or Squoosh that make finding that perfect balance between size and quality easy. Simply upload your resized image and download the compressed version.
3. Name it Descriptively: Finally, give your file a sensible name before you upload it. Think blue-suede-shoes-sale.jpg instead of IMG_1234.jpg. It's a small detail, but it’s great for your own organisation and helps with accessibility for people using screen readers.

Following these steps will make sure your images don't just look fantastic—they'll also help create a seamless, positive experience for everyone on your list.

How to Actually Get Your Images into an Email

Putting an image into your email campaign might sound a bit technical, but the way it's done is actually very clever and quite simple. We don't attach images like you would with a personal email. Doing that would make the email massive, slow to load, and a prime target for spam filters.

Instead, we link to them. This means your image lives on a server somewhere on the internet, and the email simply pulls it in for display when your subscriber opens it. This is the industry-standard for a good reason: it keeps your email's file size incredibly small. A tiny email has a much better shot at landing in the inbox and loads in a flash for your reader. It's also the magic behind tracking email opens—that little request to fetch the image is what tells your email platform that someone's looking at your message.

Step 1: Host Your Image Online

Before an image can show up in an email, it needs a home on the web. This is called hosting. For most small businesses in the UK, the easiest and best place to host your campaign images is on your own website.

If you're using a platform like WordPress, you’re already good to go. Your website's Media Library is the perfect spot to keep the images you'll be using in your emails.

A simple step-by-step for WordPress users:

1. Log in to your WordPress dashboard.
2. On the left-hand menu, click Media > Add New.
3. Drag and drop your optimised image file (blue-suede-shoes-sale.jpg, for example) into the upload area.

Uploading is a doddle. Just log into your website's back end, navigate to the media library, and upload the optimised image file you prepared earlier.

Step 2: Grab the Correct Image URL

Once your image is uploaded, it gets its own unique web address, or URL. This link is the key piece of information you'll need for your email. Finding it is usually just a click away.

How to find the URL in WordPress:

1. After uploading, go to your Media Library.
2. Click on the image you just uploaded to see its details.
3. On the right side, find the "File URL" field and click the "Copy URL to clipboard" button. The URL should end in .jpg or .png.

A Couple of Common Pitfalls to Sidestep:

• Don't use the page link: Avoid copying the URL from your browser's address bar if you're just viewing the image on a page of your site. You need the direct link to the image file itself, which will almost always end in .jpg, .png, or .gif.
• Check for private links: Make sure the image isn't stored in a password-protected part of your site. If it is, your subscribers won't be able to see it.

Step 3: Pop the Image into Your Email Template

Right, the final step: getting the image into your email layout. Modern email marketing platforms like Astonish Email make this incredibly straightforward with drag-and-drop editors. You won’t have to look at a single line of code.

Here's how it usually works:

1. Open Your Campaign: Head into your email service provider and either start a new campaign or open an existing template.
2. Add an Image Block: Look for an 'Image' content block in the editor menu. Drag it over and drop it exactly where you want your picture to appear.
3. Provide the URL: Click on the new image block. The editor will ask for the image. Instead of uploading the file again, look for an option that says something like "Insert from URL" or "Add image from URL".
4. Paste and You're Done: Paste the URL you copied from your website into the box, click 'Insert', and voilà! Your image will pop up right there in your email draft.

Most platforms give you some simple but powerful editing tools, too. It's worth exploring the different features of Astonish Email to see how you can tweak and manage your visuals without ever leaving the campaign builder. By using this hosting method, you make sure your images in email are delivered efficiently, look sharp, and help your campaign hit its goals.

Getting Your Emails Seen, Understood, and Looking Great Everywhere

You’ve designed a beautiful email. Fantastic. But the job’s not done yet. For that campaign to actually work, it needs to do three things perfectly: land in the inbox, be clear to every single recipient, and look flawless on any screen. This trio of deliverability, accessibility, and mobile design is what separates the campaigns that get results from the ones that get ignored.

Let's walk through how to balance these three crucial elements so your images in email are a help, not a hindrance.

Keeping Your Emails Out of the Spam Folder

Email providers like Gmail and Outlook are incredibly wary of spam. One of the oldest tricks in the spammer's playbook is to send an email that's just one big image, or has far more image content than text. This was a classic way to hide dodgy links and keywords from spam filters.

To steer clear of this trap, you need to find a healthy balance. While there’s no single magic number, a solid rule of thumb is the 60/40 rule. Aim for at least 60% text to 40% images. This ratio gives spam filters enough text to scan and understand that your email is legitimate, which dramatically boosts your chances of hitting the inbox.

Practical Example: A Restaurant Newsletter

• Bad (Spam Risk): An email that is a single, large image of a flyer advertising a new menu.
• Good (Deliverable): An email with a smaller hero image of the new dish at the top (25% of content), followed by a headline and text describing the menu (65% of content), and a footer with contact details (10% of content).

For a deeper dive into what it takes to maintain a solid sending reputation, have a look at our complete anti-spam policy.

Making Sure Everyone Can Understand Your Images

Accessibility isn't a technical chore; it's about basic good manners. It ensures every subscriber, including those using screen readers or those whose email clients block images by default, can get value from your message. This is where alternative text (alt text) becomes your secret weapon.

Alt text is just a short, descriptive sentence that explains what an image is about when it can’t be seen. It’s the safety net that makes sure your message always lands, no matter how the email is viewed.

A Quick Guide to Writing Great Alt Text

1. Be Specific but Brief: Describe the core subject of the image. If it’s a product, say what it is.
2. Focus on the "Why": What’s the point of the image? Your alt text should get that purpose across.
3. Don’t State the Obvious: You can skip "Image of..." or "Picture of...". Screen readers already announce that it's an image.
4. Aim for Under 125 Characters: It's not a hard-and-fast rule, but it's a good benchmark to ensure most screen readers will read the whole description.

Practical Step-by-Step for Adding Alt Text:

1. In your email editor, click on the image you've inserted.
2. Look for an "Image settings," "Options," or "Alt text" field in the editor panel.
3. Type your descriptive text directly into this field.
4. Save your changes. The alt text is now embedded in the email's code.

Taking a few seconds to write good alt text makes a world of difference for an inclusive and effective email.

Designing for a Mobile-First World

Well over half of all emails are now opened on a mobile phone. That means your design has to be perfect on a small screen. Large, fixed-width images will shatter your layout, forcing people to pinch and zoom just to read your content—a guaranteed way to make them hit delete.

The answer is to use responsive or fluid images. These are simply images that automatically scale to fit the screen they're viewed on. Modern email platforms like Astonish Email do this for you, ensuring your campaigns look great on desktops, tablets, and phones without any extra effort on your part.

File size is another huge factor. Mobile data can be patchy, and a huge email will take forever to load. It's vital to learn how to reduce file size of photos without losing quality so your emails load quickly for everyone. By keeping your images light and your design fluid, you show respect for your subscribers' time and data, which always leads to a better experience.

Driving Clicks with Dynamic and Interactive Images

Static images are reliable, but if you really want to make someone stop and take notice, a bit of movement can work wonders. Think about it – in a crowded inbox, an animated GIF or a video thumbnail can be the thing that grabs your subscriber’s attention and turns a quick scan into a proper click.

These aren't just flashy gimmicks; they’re genuinely powerful tools for getting your message across. A simple animation can show off a product feature far better than a string of photos ever could. And nothing says "click me" quite like the promise of a video.

Let's look at how you can use these visuals to build a more compelling story in your emails, without weighing them down.

The Power of the Animated GIF

A GIF is essentially a bite-sized video clip for your product or brand. It's a brilliant way to showcase different product options, highlight a key feature in action, or just inject a bit of personality into your campaign. Best of all, they're supported by nearly every email client out there, making them a safe and effective bet.

Practical Example: An Online Clothing Shop
Imagine a UK-based clothing shop. Instead of cluttering their email with three separate photos of the same dress, they could use a single GIF showing a model wearing it in three different colours. It’s far more elegant, saves space, and immediately gets the point across.

Pro Tip: Keep your GIFs short and sweet. A simple, seamless loop of 2-4 seconds is perfect. The aim is to communicate one idea quickly, not create an epic animation. And always keep an eye on the file size to make sure it loads instantly.

How to Add a GIF to Your Email

Popping a GIF into your email is no different from adding a regular image. You just need your file ready and a link to it.

1. Create or Find Your GIF: You can make your own with various online tools (like Giphy or Ezgif) or source one that fits your brand's style. Just make sure it’s optimised for email – under 200KB is a good target.
2. Host the GIF: Upload the .gif file to your website’s media library, exactly as you would a JPEG or PNG.
3. Copy the URL: Grab the direct web address for your hosted GIF.
4. Insert it into Your Email: In your Astonish Email campaign, just drag an image block into your design and use the "Insert from URL" option to paste your link.

That’s it! The animation will play automatically as soon as the email is opened, grabbing your reader's attention from the get-go.

Using Video to Skyrocket Engagement

While you can't actually embed and play a full video directly in most emails (yet!), you can do the next best thing: use an eye-catching thumbnail that links to your video. It's a well-known trick for boosting click-through rates because the little play button icon is a powerful psychological nudge that people find hard to resist.

This strategy really pays off. Research in the UK has shown that simply putting the word 'video' in an email subject line can lift open rates by 19% and increase click-through rates by a massive 65%. When the email itself contains a link to video content, that engagement can jump by as much as 300%. If you're interested in the numbers, you can explore these compelling email statistics for more detail.

Practical Step-by-Step for Video Thumbnails:

1. Take a Screenshot: Play your video and pause it on an engaging frame. Take a screenshot.
2. Add a Play Button: Use a simple editor (like Canva) to overlay a "play button" graphic onto the screenshot. This is the visual cue.
3. Save and Optimise: Save this new image as a JPEG and compress it.
4. Insert and Link: Insert this image into your email just like any other. Then, click on the image and add a link pointing directly to where the video is hosted (e.g., on YouTube or your website).

When a subscriber clicks the "play" button image, they’re whisked away to your landing page to watch the full demo.

Turn Insights into Action: Testing and Measuring Your Images

Right, so you've designed a stunning email, packed with compelling images. But don't hit that 'send' button just yet. Sending an email without testing it first is like flying blind. To turn your visual strategy from a shot in the dark into a reliable way to get results, you need to test beforehand and measure what happens afterwards.

It’s a frustrating truth of email marketing that a campaign can look absolutely perfect on your screen but be a complete mess for a subscriber using an old version of Outlook. Every email client—from Gmail to Apple Mail to the various mobile apps—has its own quirks for displaying HTML and images. This is why a quick preview across different platforms isn't just a nice-to-have; it's a must-do.

Test Before You Send

The whole point of testing is to make sure your email looks fantastic for everyone, no matter what device or email provider they're using. This is where testing tools are worth their weight in gold.

• Email Client Previews: Services like Litmus (which we’ve built right into Astonish Email) are brilliant for this. They generate screenshots of your email as it will appear in dozens of different clients. In a few seconds, you can spot and fix rendering problems before a single customer sees them.
• A Simple Self-Test: If you're on a tight budget, at the very least, send a test campaign to yourself. Make sure you have accounts on the big platforms—like Gmail, Outlook, and maybe a Yahoo account for good measure. Check it on your computer and your phone to see how your images in email are behaving on different screen sizes.

Measure What Matters

Once your campaign is out in the wild, your analytics dashboard becomes your best friend. It’s time to look beyond the basic open rate and dig into the metrics that show how your audience is actually engaging with your visuals.

The real gold is in knowing not just that people clicked, but what they clicked on. When you can see which specific images are getting the clicks, you know which visuals are actually working.

Here are the key metrics to keep an eye on:

• Click-Through Rate (CTR) on Images: Are people clicking on that big, beautiful banner image, or is it the smaller product photos that are getting all the attention? This tells you what your audience finds most persuasive.
• Heatmaps: Some platforms can show you a heatmap—a visual overlay of your email highlighting the "hotspots" where people clicked the most. It's a fantastic way to see which part of a hero image or which call-to-action button really grabbed people's focus.

Use A/B Testing to Continuously Improve

The single best way to refine your image strategy over time is through A/B testing, sometimes called split testing. The idea is simple: you send two slightly different versions of your email to small, separate groups of your audience to see which one performs better.

Here’s a straightforward way to start testing your images:

1. Form a Hypothesis: Start with a question you want to answer. For instance: "I wonder if a lifestyle photo showing our product in use will get more clicks than a clean, simple studio shot?"
2. Create Two Versions: Make a copy of your email. In Version A, use the lifestyle photo. In Version B, use the studio shot. The crucial part? Keep everything else—the subject line, the copy, the offer—identical.
3. Send and Analyse: Your email platform will send Version A to one slice of your list and Version B to another. After a while, you'll see which version's image drove a higher click-through rate.
4. Apply Your Findings: Roll with the winner! Use the image style that performed best in your next main campaign.

By making this test-measure-learn cycle a regular habit, you create a powerful feedback loop. Every single campaign you send will be a little bit smarter than the last.

Common Questions on Using Images in Emails

When you're first diving into using images in your email campaigns, it’s natural to have a few questions pop up. To help you get it right from the start, I’ve put together answers to some of the most common queries we hear from UK small business owners.

What’s the Right Balance of Text to Images?

There’s no single magic formula, but the golden rule of thumb is to aim for a ratio of about 60% text to 40% images. This balance is crucial for a couple of reasons.

Firstly, it gives spam filters enough text to scan and understand that your email is legitimate, not just a flashy advertisement. Secondly, it ensures your main message still gets across even if a subscriber has images turned off in their email client. Whatever you do, avoid sending an email that is just one big image – it’s a massive red flag for spam filters and a frustrating experience for many of your readers.

How Do I Stop My Email Images from Being Blocked?

The short answer is, you can't. Many email clients, like Outlook, block images by default as a security measure. The power to display them is entirely in your subscriber's hands.

But don't worry, you can definitely nudge them in the right direction. Here are four practical things you can do:

1. Always write compelling alt text. This is the text that appears before an image loads. If it clearly describes what’s missing, it can pique their curiosity enough to click "Display images."
2. Build a relationship. People are far more likely to download images from a sender they know and trust. Consistent, valuable content is key.
3. Ask to be added to their contacts. A simple line in your welcome email encouraging new subscribers to add you to their address book can make a huge difference. For example: "To make sure you never miss an update, please add our email address to your contacts."
4. Never put your CTA in an image. Your most important links and calls-to-action should always be plain text links or coded HTML buttons so they work whether images load or not.

What’s the Ideal File Size for an Email Image?

For a smooth, fast-loading experience, try to keep each individual image under 200KB. Even more importantly, the total size of all images in your email should stay below 1MB.

Why does this matter? Heavy images can make your email painfully slow to open, especially for people checking it on their phone with a patchy connection. That lag is often all it takes for someone to lose patience and hit delete. Before you upload any image, run it through a free online compression tool. It’s a quick step that shrinks the file size without any noticeable drop in quality, ensuring your email looks great and loads instantly for everyone.

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Ready to create beautiful, effective email campaigns in minutes? With Astonish Email, you get a simple drag-and-drop builder, mobile-friendly templates, and all the tools you need to turn your emails into business growth. Get started for free today.