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Gmail Data Analysis Reveals Image Blocking Affects 43% of Emails


When Google announced that images in emails will now show automatically. We’ve kept a close eye on the increased open counts in Gmail—automatic image downloads have given us a unique opportunity to examine the impact that image blocking has had on email marketing for years. What we’ve learned is fascinating, and unveils a critical metric unknown to email designers before now.

By comparing open rates before and after Gmail’s switch to automatic image downloads, we can tell how many people view emails without displaying images. When Gmail still blocked image downloads, 57% of Gmail users turned images on.

What about other email clients that block images?

While Gmail isn’t blocking images any more, many email clients still do. If we look at the difference between people reading with images off vs. images on, we can extrapolate that difference to other email clients that block images. Clients that block images would see about a 26% increase in opens, while those that download images would see a 4% decrease.

Email ClientApril %Adjusted %Change
Apple Mail7.90%7.55%-4.43%
Windows Live Mail2.33%2.95%26.61%
Windows Mail1.74%2.21%27.01%

Show your work

If math is your thing, Matt Brindley (Litmus co-founder and CTO) reveals the data behind the analysis.

Defensive design for image blocking

You can use a Litmus account to preview how your email looks in email clients that still block images. After taking stock of how your emails look with images disabled, consider using “defensive design” techniques to combat the effects of image blocking:

  • Using clear and appropriate ALT text on images. Ensure your email is readable and gets the point across, even without images.
  • Don’t put key copy in images—nearly half of your readers will not see it!
  • Consider styling your ALT text. This gives you an opportunity to grab your reader’s attention, even if images are disabled.

Get defensive with image blocking

With Litmus Checklist, you’ll get previews of your emails with images-off, and will get notified if any of your images are missing ALT text. Send with confidence every time.