Email design best practices for desktop and mobile

Email design plays a big role in how subscribers engage with your emails. Since subscribers read emails on both desktop and mobile devices, designing with device behavior in mind helps improve opens, clicks, and overall readability.

Note: These email design best practices are not unique to Flodesk. They are universal email marketing principles that apply across all email platforms, but understanding why they work helps you customize your emails more effectively.

Before you design, check how your audience engages.

You can see whether your subscribers prefer desktop or mobile by reviewing your email reports:

• Available for both standalone emails and workflow emails

• Look at click data by device

Use this insight to decide whether to design mobile-first or balance equally between desktop and mobile.
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If most of your subscribers read and click emails on their phones, prioritize mobile readability.

Since emails are built on desktop, always send yourself a test email and view it on your phone.

Ask yourself:

• Is the text easy to read?

• Are buttons easy to tap?

• Does anything feel cramped or overwhelming?

Adjust spacing, font size, or layout as needed.
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Mobile inboxes show fewer characters.

Best practice:

• Short, clear subject lines

• Preview text that complements (not repeats) the subject line

Always check how both appear in a mobile inbox when reviewing test emails.check your test email on your phone.
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Small screens make small text harder to read.

Recommended starting points:

• Body text: at least 14–16px

• Headings: large enough to clearly stand out from body text

• Avoid long paragraphs. Shorter text blocks improve scannability on mobile.
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“Above the fold” means what’s visible before scrolling.

Place these early in your email:

• Main message or value

• Primary call-to-action (CTA)

Large images can push important content too far down. Consider placing images after your main CTA.
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These principles apply no matter which device your subscribers prefer.

Inbox competition is high. Clear, concise emails perform better.

Why this matters:

• Long emails feel overwhelming on mobile

• Shorter emails load faster

• Focused messages increase click-through rates

• One email = one main goal. Avoid competing CTAs whenever possible.

Spacing improves readability and prevents emails from looking cluttered.

Best practice:

• Use 20–40px spacers between blocks

• Keep spacing consistent throughout the email

Always preview spacing on mobile to make sure it doesn’t feel too tight or too spread out.
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CTA buttons should be:

• Clear

• Short

• Easy to tap

Examples that work well:

• “Buy now”

• “Read more”

• “Save my spot”

Avoid long CTA text. On mobile, long text can wrap onto multiple lines and make buttons look broken.

Make buttons large enough for thumbs. Small buttons reduce mobile clicks.

Images should support your message, not overwhelm it.

Best practices:

• Avoid stacking too many large images

• Balance images with text

• Make sure important information is not only inside an image

• Add alt text to images

Always assume images may load slowly or be blocked. Your email should still make sense without them.
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Use the paper plane icon in the Flodesk Email Builder to send test emails.

Check your email on:

• Desktop

• Mobile phone

• Different inboxes if possible

Flodesk templates are optimized for both devices, but testing is essential after customization.

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To design effective emails for desktop and mobile:

• Check your subscriber device preferences in email reports

• Design mobile-first if most clicks happen on phones

• Keep content short, scannable, and focused

• Use clear CTAs and consistent spacing

• Always preview and test before sending

Are these email design best practices specific to Flodesk?
No. These are universal email marketing best practices that apply to all email platforms.

Should I always design emails for mobile first?
If most of your subscribers click emails on mobile, yes. If your audience is evenly split, design with both desktop and mobile in mind and always test on both.

What font size should I use for mobile emails?
Body text should generally be at least 14–16px. Headings should be noticeably larger for clear hierarchy and readability.

How long should my emails be?
Shorter emails perform better, especially on mobile. Focus on one main message and one primary CTA whenever possible.

Why do my buttons look broken on mobile?
This usually happens when CTA text is too long and wraps onto multiple lines. Use short, clear button labels.

Do I need to test my emails if I use Flodesk templates?
Yes. Templates are optimized by default, but changes to spacing, text, or images can affect how your email looks on different devices. Always send a test email before publishing.