Beefree blog

How to Optimize Images for Your Mobile Emails

Emily Santos
Emily Santos
Jul 1, 2016
How to Optimize Images for Your Mobile Emails
How to Optimize Images for Your Mobile Emails

Originally published on June 30, 2016. Last updated July 30, 2021.The rate of email opens on mobile is consistently increasing, with almost half of all emails opened on smart phones in 2021.

Responsive mobile emails compared to other devices

As webmail and desktop environments become less popular, it’s important for marketers and designers alike to keep up with best practices for mobile design. Factors like accessibility, image size, quality, and format not only affect how the design renders, but also impact important email marketing metrics like deliverability and conversion rates.If you’re new to optimizing for mobile design, you might be wondering: why do images in emails sometimes look pixelated on smartphones? What's the best size for an image in email? Why does my email show up differently depending on the ESP of the user?Let’s answer each question by running through best practices for mobile email image optimization. Add these tips to your design toolbox for future email campaigns.

Best practices for mobile design 

In order to create the best user experience, it’s essential to implement responsive email images for mobile. Smaller screens on mobile call for more accomodating design components, which could be intimidating or confusing at first. But keep in mind that optimizing for mobile should be user focused. Consider your users needs and then bring these best practices into every email you design.

Choose the highest quality photo

High-quality images are one of the most important aspects of image optimization. To ensure your images are showing up correctly in your email, you first need to evaluate their quality.Expert designers use DPI or dots per inch to measure the quality of an image. For guaranteed high-quality images, set your resolution to 72 DPI while also increasing the dimensions of the image. This will give high-DPI displays, which have increased pixel densities and more image data to utilize. This means that setting the DPI to this optimal resolution gives enough space for images to appear crisp.Implementing these changes will prevent blurriness and assure that your images are always looking sharp. When you don’t account for high-DPI displays your image will appear pixelated as it stretches across the screen. This means that you will typically want images to be twice as large for the best image optimization.It’s also important to think about your image’s color values. Avoid CMYK (cyan, magenta, yellow & black (key)) color values since they are solely meant for print and won’t work well on a digital screen. Keep images in RGB (red, green, blue) color values, which allows you to adjust for saturation and vibrancy. This is the best way to create the highest quality image.

Optimize image size

Always consider the dimensions of your images when inputting them into your emails. If images have larger-than-normal dimensions, they may not render well. It’s concerning and makes you question if subscribers will have issues upon opening the email and viewing the images?In short, the file size does play a role when the images are downloaded. The image size impacts the total time it takes for the content of the email to fully render once it's opened. On a mobile device, when the reader might have a slow Internet connection speed, the time lag could be substantial.Avoid this issue by optimizing your image size. We recommend adjusting your content area width to around 600px for the highest quality image. While images will adjust according to the device the email is open on, hit this size to make sure they render correctly on all devices. Leaving the size to chance will lead rendering to chance, especially with so many different file formats as well.

Select the best image format

There are so many file formats, it is often confusing to figure out which one will result in the highest quality images. PNGs, JPEGs and SVGs tend to be the most well-known and widely accepted file formats.While there are pros and cons to each format, you can use the guidelines below to choose the right file type for your needs. Also note, some formats may increase your image size, so use the EZGIF program to compress your image to keep in line with the quality you have adjusted for. So, which image format is best:

  • PNG: These are lossless, meaning they won’t falter in quality when you compress the image which allows you to export with transparency. There are PNG-8, 24, and 32 files, so the standard practice here would be to decide on a proper balance of file size and color to suit your email best.
  • JPEG: These won’t allow transparency and are quite lossy. Use when your images are loaded with color.
  • SVG: These are a vector format which allows you to resize your image to fit your needs without losing the quality of your image. 

There is no correct answer as to which format is best, but think about which one would fit your needs. If you are looking for something to easily export with transparency go with PNG format. Or use JPEG when you are using images with tons of color. Utilize the format that will give you the highest quality image.

Make your images accessible

The quality, size and file format of your images are set for success, but you have one last crucial factor to consider: Is your email accessible to everyone?Visually impaired individuals will not be able to decipher image-heavy emails that aren’t intentionally made accessible. It’s important to include accessibility concerns to avoid isolating users with disabilities.The two accessibility components that you shouldn’t go without are Alt text and color contrast.

  • Alt Text. This Alternative Text attribute is an image description that gives those using screen readers the opportunity to visualize what your picture is portraying. Consider what purpose your image serves inside your email to allow for proper alt text functioning
  • Color Contrast. Be mindful of your color choices in regards to your images and other email components. Distinguishing between colors is difficult for many, so try to increase the contrast between the email text, image and background. Refer to this color oracle for more on this. Especially think about this when trying to utilize background images, since older emails like Outlook don’t render those. If you choose to use a background image be sure to set a safe fallback color. 

Also be mindful of flashing graphics, color patterns or other special effects that may be dangerous to some image-sensitive subscribers. Seizures can be caused by bright, strobing images, so make sure to avoid those at all costs. Be sure to account for these image accessibility factors along with other email design elements including copy spacing, font size and other design elements.

Mobile Design Mode

We’ve gone through all of the best practices for optimizing your mobile design, including:

  1. Choose the highest quality photo
  2. Optimize size
  3. Select the best image format
  4. Make your images accessible

But the best way to make sure that your emails render correctly every time is to use the right tools. BEE Pro includes a mobile design mode, where you can design for mobile-only communications. Visualize exactly what your design will look like on a mobile device while you are designing.Sign up for a BEE Pro free trial to test this out, and access more templates and features to make designing with these best practices in mind even easier.Save

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Send Error-Free Emails with Confidence Using Beefree

Learn about the Beefree features that can help you and your team catch mistakes, streamline collaboration, and send with confidence every time.
Beefree team
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We’ve all been there: You craft the perfect email, hit “send”, and just as you settle into the satisfaction of a job well done, someone slacks you: “Hey, something doesn’t look right with that campaign.” 

If this sounds familiar, you should know that you’re not alone: According to the 2025 Really Good Email Survey “90% of email marketers say they have a history of noticing mistakes in their emails after they’ve hit the send button.

This becomes especially common when your team constantly juggles multiple campaigns or makes edits until the last minute. Sadly, even the smallest mistakes don’t just slip through the cracks; they cost you.

Luckily for us all, mistakes can be avoided. And no, not by lighting a Pre-Send Protection Candles™ and hoping for the best. But rather by equipping your team with the right tools that work with your team – not slow them down. Let’s talk about it!

Building your team’s safety net for mistake-free emails with Beefree 

When everyone involved in the email creation process is aligned and supported by smart systems, executing mistake-free emails becomes second nature. Instead of scrambling to do damage control, you’ll want to set up the tools and processes that help your team focus on what they do best: creating emails that connect, convert, and confidently represent the brand.

In this article, we’ll discuss how you can use Beefree to: 

  • Reduce human errors 
  • Implement systems of checks and balances 
  • Establish guardrails & frameworks for on-brand email design

1. Catch mistakes before they happen with Smart Check

Missing links that lead nowhere? Forgotten subject lines? HTML emails that get clipped in Gmail? It’s easy to make little mistakes that derail your campaign’s performance. 

Learn more about Smart Check → 

Beefree’s Smart Check automatically checks your designs and alerts you of any red flags so you can fix them before they cost you opens, clicks, or conversions. Think of Smart Check as your built-in QA partner who will catch:

  • Missing links
  • Heavy images that could slow down email load times
  • Missing subjects & preheaders that impact engagement
  • Missing alt text on images that hurt your email’s accessibility
  • Large HTML files that might affect deliverability (or get clipped in Gmail)

2. Keep every email on-brand with built-in guardrails 

Most of us don’t nail the perfect campaign on the first try. Great emails are a team effort. However, when multiple teams are involved in the email creation process, branding can quickly go off the rails. 

A misused font, clashing colors, or buttons that are too small to click don’t just make emails look disjointed—they can damage your brand’s credibility.

With Beefree’s Advanced Style Kit, you can set clear, predefined guidelines for fonts, colors, spacing, and more—so every design starts on the right foot. Once configured, all new emails automatically inherit your brand styles, reducing the need for constant oversight and minimizing errors.

Advanced user permissions let you lock down specific design elements, giving you full control over what can (and can’t) be edited. That means anyone on your team—regardless of design expertise—can confidently create emails that look and feel like your brand.

3. Empower your team to create with confidence with reusable content

When your team isn’t bogged down by the cumbersome process of creating content from scratch (or fear of going off-brand), they can move faster—and with far more confidence.

With Saved and Synced Rows, you can provide your team with pre-approved content blocks—like headers, footers, and other commonly used design elements—that they can use in their designs without creating them from scratch. That ensures design consistency, eliminates redundant work, and makes email creation a lot faster.

Learn more about Saved Rows → 

4. Ensure your team is aligned with centralized reviews and approvals:

Creating the perfect email often takes a team of designers, copywriters, marketers, and other team members working together. But when multiple people are involved, endless back-and-forth and feedback scattered across multiple conversations and channels can slow things down, lead to miscommunication, and ultimately cause mistakes. 

With Beefree’s built-in commenting, your team can collaborate and share feedback where the work is actually happening—right inside the builder. And if you’d like to involve external reviewers into the review process, you can do that as well. 

Learn more about commenting → 

Plus, with Beefree’s built-in Approval flow, you can ensure your designs are reviewed and approved by the right stakeholders. Stay aligned with real-time notifications on design changes, lock edits on approved content, and get a clear view of project status for smoother team collaboration and high-quality results.

Learn more about Approvals →

5. Need an additional pair of eyes? Use the power of AI to support your team

Take some weight off your team's shoulders and use AI to support them in the final stretch. Whether it’s catching typos, flagging inconsistencies, or suggesting optimization, AI can be a saving grace when deadlines are creeping in.

For those times when you can’t remember the difference between “there, their, and they’re,  Beefree’s  AI Writing Assistant is there to help. This eager-to-learn helper can  review your copy for grammatical errors, tone of voice, and even share suggestions for making it just a bit more compelling. Our AI Writing Assistant can also seamlessly translate content or automatically generate ALT text for images to enhance the accessibility of your emails. 

Learn more about AI-powered content creation in Beefree →

The tangible cost of email mistakes

Mistakes don’t just impact performance; they slowly erode credibility. What starts as a small oversight can be a massive inconvenience for your readers, sending them straight to the unsubscribe button. As for your team, mistakes chip away at their confidence. Instead of brainstorming for the next campaign, they’re scrambling trying to figure out how to do damage control.   

When done right, email is a powerful tool for connecting with your audience. But a single mistake can unravel that connection and undermine trust.

  • A missing or broken links can interrupt your subscribers’ journey to conversion, negatively impacting campaign performance.
  • A missing subject lines means your emails won't stand out in the inbox, hurting your open rate
  • An awkward typo might signal a lack of attention to detail
  • An off-brand design can make your brand look disorganized
  • An email that gets clipped in Gmail because it’s too big means some subscribers might never see the full email content.

Design error-free emails and send with confidence with Beefree 

Beefree helps teams of all sizes create polished, on-brand emails—without the risk of costly errors. With built-in safeguards, streamlined approval flows, and collaboration tools that keep everyone aligned, Beefree acts as your team’s system of checks and balances. From first draft to final sign-off, you’ll have everything you need to send with confidence, build trust, and get results.

Try Beefree's Business for free for 15 days and get access to all of Beefree’s tools that help you catch mistakes, streamline collaboration, and send with confidence every time. Or schedule a call with one of our experts to discover everything Beefree can support your team.

Using Beefree with Marketo Engage 101

Learn how integrating Beefree with Marketo Engage can help you build high-converting, on-brand email campaigns— faster.
Luca Penati
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Marketo Engage is a powerful tool for marketing automation, but when it comes to email design flexibility, many users find its built-in editor limiting. Creating visually compelling, mobile-responsive emails often requires custom coding or workarounds, slowing down workflow and making it harder to execute high-quality campaigns efficiently.

That is where Beefree comes in. By integrating Beefree’s no-code, drag-and-drop email design platform with Marketo Engage’s advanced automation capabilities, teams can build professional, responsive emails without coding headaches and push them directly to Marketo in just a few clicks.

This article explores:

  • The challenges of designing emails directly in Marketo
  • How Beefree solves these pain points
  • A step-by-step guide to integrating Beefree with Marketo Engage
  • Common FAQs and troubleshooting tips

The challenges of designing emails directly in Marketo

Marketo’s built-in email editor is useful for basic templates but presents several limitations for marketers and designers.

  • Limited design flexibility – Customizing layouts, fonts, or interactive elements can be difficult without custom HTML or Marketo’s proprietary syntax.
  • Technical barriers – Advanced customizations often require HTML knowledge or an understanding of Marketo’s email template language, which may not be ideal for non-technical teams.
  • Time-consuming manual processes – Without a centralized style kit, teams may struggle to stay on-brand and often have to manually recreate headers, footers, and other reusable content blocks for each email, adding extra steps and slowing down production.

Due to these challenges, many marketing teams turn to external email builders like Beefree, FeedOtter, or Knak to improve design efficiency and automation.

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Why Beefree is the best email builder for Marketo Engage

While other external email builders like Knak and FeedOtter also integrate with Marketo, Beefree offers distinct advantages.

  • No-code drag-and-drop builder – Enables teams to design professional emails without writing any code.
  • Advanced design features – Provides more customization options beyond what Marketo’s built-in editor allows.
  • Mobile-responsive templates – Ensures emails adjust automatically for both desktop and mobile devices.
  • One-click export to Marketo – Simplifies the process of moving email designs directly into Marketo Engage.
  • Ability to update existing templates – Allows quick updates without requiring manual re-imports of HTML files.
  • Team collaboration – Enables teams to work together in real time, with built-in guardrails and approval controls to ensure error-free emails before exporting.

By integrating Beefree with Marketo, marketing teams eliminate design frustrations and manual email imports, allowing them to focus on high-performing email campaigns.

Learn more about Beefree's integration with Marketo Enagage [https://support.beefree.io/hc/en-us/articles/24837761625618-Export-Emails-to-Marketo]

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How to update existing email templates in Marketo

Instead of manually editing HTML, Beefree allows users to edit emails in Beefree and update existing ones in Marketo Engage with one click.

  1. Open the email design in Beefree.
  2. Make changes and click “Export.”
  3. Select “Update Existing” to overwrite the previous version in Marketo Engage.

This feature ensures that emails and templates remain up to date without requiring complex HTML edits or duplicates.

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Frequently asked questions on using Beefree with Marketo Engage

Can I use Beefree with other ESPs besides Marketo Engage?

Yes! You can connect Beefree to any ESP, MAP, or CRM including Mailchimp, HubSpot, Salesforce Marketing Cloud, and others. To learn more about how to integrate Beefree to your sending platform watch the video below: 

For a full list of our native integrations visit [https://beefree.io/integrations].

Are there any limitations when exporting Beefree emails to Marketo?

Yes, there are a few important limitations to be aware of:

  • Charset emojis are not supported in Marketo. Including emojis in your email content may result in an error. To prevent this, Beefree automatically replaces unsupported emojis with a placeholder. For more details, refer to the [Marketo documentation on emoji support].

Preheader text is not a native field in Marketo. However, Beefree includes it by embedding the preheader directly in the email's HTML code during export.

Additional resources and links

Why you should use Beefree with Marketo Engage

By integrating Beefree with Marketo Engage, marketing teams gain a faster, more flexible way to build high-converting, on-brand email campaigns—while leveraging Marketo’s powerful automation and analytics to track performance and optimize results.

  • Design responsive, professional emails with ease.
  • Maintain brand consistency across every message.
  • Collaborate efficiently and gain insights to improve campaign performance.

Ready to elevate your Marketo email marketing? Try Beefree today and streamline your entire email creation process.

Start your 15-day free Business trial today!

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