Put your subject lines to the test.

Maximize your email open rates with Subject Line A/B Testing.

HOW TO RUN AN EMAIL SUBJECT LINE TEST.

Create an email with two subject lines.

Send the test to a portion of your contact list.

We automatically send the winner to your remaining audience.

Watch your email open rates soar.

INCREASE YOUR OPEN RATES. IMPROVE YOUR EMAIL CAMPAIGNS.

Email marketing experts agree: Running an A/B test on subject lines maximizes your email open rates. It’s a best practice used across the industry, and Constant Contact makes it easy to implement in your email campaigns. Our tool enables you to test two subject lines on a percentage of your target audience, then automatically sends the winner to the remainder of your contact list.

A subject line is the first impression you’ll make on your readers. Make it count.

How to Write a Great Subject Line »

THE BEST SUBJECT LINE. EVERY TIME.

With Subject Line A/B Testing, confidence comes easy. Turn any email campaign into an A/B test to make sure you’re sending a subject line proven to generate more opens and increase customer engagement.

Create your email

Use our best-in-class editor to create an email for testing. Simply start a new email from the campaign picker, then select Subject Line A/B test.

Customize your audience

Select the percentage of your contact list that will receive each subject line. To achieve statistical significance, we recommend testing each line on at least 1,000 contacts, if possible.

Set test length

Choose how long to wait—6, 12, 24, or 48 hours—before declaring a winner. The tool selects the best subject line based on the number of opens, and automatically sends it to your remaining audience.

Track your results

While the test is active, access real-time reporting to view engagement for each audience and which line is in the lead. Then see how the winning subject line performed overall.

The most effective subject lines contain around 4-7 words or 40 characters.

11 Surefire Secrets to Standout Subject Lines »

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