How long should an email be? It’s a question that’s crossed every sender’s mind at some point (and for good reason). A 2023 US survey from Statista tells us that for every three people who pay attention to emails, nine ignore them. With sobering numbers like this, it’s fair to assume that every email you send operates on a tight margin.
So, how long should your email be to increase its chances of success? Most studies suggest that 50-125 words yield the highest click-through rates, but the truth is more nuanced.
The “perfect” email length can vary dramatically depending on why you’re emailing, who you're writing to, and how well they know you. A cold sales email, for instance, needs different treatment from a newsletter update to loyal customers.
To help you get it right, this guide provides data-backed recommendations on the ideal email length alongside a few proven email campaign best practices to boost your response rates.
What Does the Data Say About the Best Email Length?
Click-through rates (CTR) are one of the clearest indicators of email marketing success, and your email length plays a bigger role here than you might expect.
A study published in the Technological Forecasting and Social Change Journal found that longer email body lengths correlate strongly with lower CTRs. In other words, the study suggests that the more you write, the more you risk being ignored.
Not surprisingly, this trend aligns with broader industry findings. In a recent study, Constant Contact reviewed over 2.1 million emails and found that those with about 20 lines of text (roughly 200 words) got the highest CTRs:
Boomerang’s research took things even further. After analyzing 40 million emails, they pinpointed the sweet spot for engagement at 50 to 125 words. Emails in that range earned click-through rates just over 50%.
What’s more, they found that emails outside this window (whether too short or too long) saw a steep decline in response rates. This tells us, in no uncertain terms, just how crucial email length is to engagement.
When Do Long Emails Work?
With all the talk about shorter attention spans today, it’s easy to think of email campaigns as a formula where long equals bad and short equals good. But that perspective is just as harmful to campaigns. Sometimes, sending out long emails may be more strategic, depending on your email’s purpose.
If, for example, you specialize in detailed content like product descriptions, feature updates, or project summaries, a longer format can actually boost clarity and trust. The key is optimizing for readability by:
- Breaking content into clear headings, subheadings, and short paragraphs.
- Using bullet points to simplify complex ideas.
- Keeping sentences concise where possible.
Most importantly, remember to front-load your value. Place the most important information at the beginning of the email to capture attention before the reader’s focus drifts.
Why Does Email Length Matter?
For the best results, it’s essential to closely monitor the impact of email length on the success of your campaign. Choosing the right length impacts everything from readability to engagement rates, and even how well your emails perform on mobile devices.
Here’s why mastering email length is essential for better campaign results:
Readability
Regardless of the length you choose, emails should be easy to read, clutter-free, and properly spaced to avoid turning potential leads away. Shorter emails, within the 50 to 200-word limit, are your best bet because they tend to be more legible and easier to skim through.
Consumer Attention
According to a 2015 Microsoft Study, the average consumer has an attention span of about 8 seconds, and it’s only shrinking as digital distractions grow. With inboxes overflowing, your email needs to grab attention instantly and hold it long enough to drive action.
To pull this off, focus on making your subject line direct and compelling, and keep your email body concise to maintain interest all the way through.
Engagement
Email length doesn’t just affect readability; it also drives critical engagement metrics like open rates, click-through rates, and replies.
Finding the right balance is key: relevant emails that are easy to skim and framed around a clear call-to-action consistently outperform those that are too brief or overloaded with information.
When your emails hit that sweet spot, they’re far more likely to spark action instead of getting lost in crowded inboxes.
Mobile Friendliness
Today, between 26% and 78% of email opens happen on mobile devices, depending on the industry. That means if your emails aren’t optimized for small screens, you’re losing a huge chunk of your audience before they even finish scrolling.
To boost mobile engagement, keep your subject lines sharp and your body text concise. Use single-column layouts for better readability, and swap hyperlinks for easy-to-tap buttons whenever possible. Small adjustments like these make it far easier for mobile readers to absorb your message and take action.
Email Length Best Practices for B2B Marketing
In the B2B space especially, attention is hard to capture and even harder to keep. That’s why every word in your email needs to earn its place.
Here are a few best practices to help you do just that:
- Keep your subject lines short and sweet to increase your chances of getting higher opens. A study published in the Journal of Marketing Communications revealed that when email subject lines were kept short, averaging six words, the open rate reached an impressive 20%.
- Keep paragraphs under three lines and use bullet points where relevant for better readability.
- Avoid cluttering emails with unnecessary marketing language or excessive visuals.
- Visual elements like images and videos can increase the length of your email. Try not to go over three to four images to improve mobile-friendliness.
- While data provides guidelines, we recommend A/B testing different email lengths and subject lines to adapt to your audience’s preferences.
- Consider providing a clear and creative call-to-action at the top of your emails to pique your audience’s attention even from the preview pane.
- For information-heavy email content, it’s best to link to more detailed additional resources instead of overloading the email body.
It’s worth noting that doing all this manually, at scale, just isn’t realistic. Sure, writing one clear, perfectly structured email is doable. But applying it to dozens of campaigns across hundreds (or thousands) of leads? That’s where it breaks down fast.
This is exactly where Instantly.ai makes life easier.
Instantly.ai is built for people running serious outbound. You can spin up entire cold email campaigns in minutes, manage multiple inboxes, track opens and replies in real time, and automatically A/B test subject lines and message lengths to see what’s working (and what’s not).
Ready to scale your B2B email outreach without losing precision? Instantly.ai is your one-stop shop. Try it today at zero cost.
Key Takeaways
To recap, emails between 50 and 200 words tend to perform better and record higher response rates. Falling outside this range often leads to a noticeable decline in response rates, except in cases where additional context is needed.
For the best results with email length, we recommend that you:
- Match your email length to its purpose; only expand when deeper context adds value.
- Stay precise and avoid redundancy to maintain reader attention.
- Prioritize mobile optimization with short paragraphs, clean layouts, and easy-to-tap CTAs.
- Use A/B testing to fine-tune subject lines, email lengths, and content for your specific audience.
Most importantly, respect your reader’s time. Whether your email ends up short or detailed, the goal is always to deliver clear, actionable value. Sign up for a free Instantly trial to scale high-performing emails without losing clarity or control.
