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2021 kicks off with Apple iPhone increasing its lead in email client market share

How is it April already? Email client popularity last year was almost as up and down as the U.S. stock market. So, I was curious to see how it played out during the first quarter of the new year. We analyzed nearly 3 billion email opens around the world with Litmus Email Analytics from January to March of 2021.

Check out our infographic here for the key takeaways, or read the transcript below it.

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2021 Q1 email client market share data from Litmus Email Analytics

Transcript: Email client market share from January-March 2021

Where are subscribers reading emails? We analyzed nearly 3 billion email opens in January, February, and March of 2021 to find out the most popular email clients, apps, and devices.

Top 10 email clients overall

Apple iPhone increases its stronghold as first place in email client market share—up almost 5 percentage points since last year. This is likely due to the immense popularity of the new iPhone 12 family.

Other interesting things to note? Google Android makes the biggest jump, moving up 3 places to #6. Outlook Mobile has lost a lot of share, now only an eighth of what it had last year. Will this give Windows Live Mail, currently #11, a chance to break through to the top 10 again? Only time will tell.

  1. Apple iPhone: 38.9%
  2. Gmail: 27.2%
  3. Apple Mail: 11.5%
  4. Outlook: 7.8%
  5. Yahoo! Mail: 5.4%
  6. Google Android: 1.5%
  7. Apple iPad: 1.4%
  8. Samsung Mail: 1.2%
  9. 0.9%
  10. Outlook Mobile: 0.2%

Opens by environment

Mobile is recovering nicely as the most popular place for emails to be opened (it took a hit in the middle of 2020). It’s still not quite as strong as it was this time last year, but we’ll see how the rest of 2021 trends.

  • Desktop: 19.4%
  • Webmail: 36.1%
  • Mobile: 43.0%
  • Other: 1.5%

Top 3 mobile opens

Apple iPhone continues to be the leader in mobile email, and it’s unlikely to be overthrown anytime soon. Google Android has shot up the mobile ranks to #2 after being stuck at #5 most of last year. Apple iPad continues its downward trend in mobile email client market share.

  1. Apple iPhone: 90.0%
  2. Google Android: 3.5%
  3. Apple iPad: 3.2%

Top 3 webmail opens

Although Gmail remains the top webmail email client, its exact share of webmail opens has been fluctuating since the pandemic started, from 71-80% and now sits firmly at 75%.’s webmail email client market share has increased 140% since last quarter.

  1. Gmail: 75.0%
  2. Yahoo! Mail: 14.8%
  3. 2.4%

Top 3 desktop opens

Apple Mail’s share of desktop opens has decreased slightly while Outlook’s has increased, but they’re still first and second place respectively. Windows Live Mail is slowly losing desktop email client market share but is likely to stay #3 for quite awhile (fourth place has significantly less share at 0.1%).

  1. Apple Mail: 58.9%
  2. Outlook: 40.0%
  3. Windows Live Mail: 0.9%

Your subscriber base isn’t the average

Email client usage differs from industry to industry and from brand to brand. Wondering how your subscribers open their email? Find out with a free trial of Litmus Email Analytics.

Litmus empowers you and your team with the tools and insights you need to ensure a consistently great brand experience for every subscriber, work more efficiently, accelerate campaign performance, reduce errors, and stay out of the spam folder.

Where did we get all this data? Our 2021 Q1 email market share data comes from nearly 3 billion email opens worldwide, anonymously collected and aggregated with Litmus Email Analytics from January 1-March 31, 2021. It highlights global trends across all industries and verticals. Some email clients may be over- or under-represented due to image blocking.

Magan Le

Magan Le

Magan Le was a Content Marketing Manager at Litmus