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Analyze and Optimize Subject Line Performance

Last updated February 2023

Analyze past Subject Line performance with Subject Line Advisor, powered by Persado. Optimize future Subject Lines prior to deployment with Subject Predict.

Navigate to Subject Line Advisor within Inbox Tracker. Not seeing it? Contact us at for details.

Select a date range and review your past engagement.

Includes average subject length, read rate, delete rate, etc.

Compare frequently used emotional triggers to the recommend ones. The Recommended Emotional Triggers had the highest read rates, but were used the least.

Emotional Insights provides a view of frequency vs. read rate. A larger bubble indicates higher frequency. Hover over to see the list of subject lines that were assigned to each emotion.

The Emotional Comparison filter lets you control which emotions you want to examine more closely. Click the emotion to filter both the chart and list of campaigns in the chart that follows.

Character Count Correlation tells you how the number of characters in your subject line affects the read rate.

Top Words & Phrases gives an additional view into the read rates of your most used words and phrases.

Here is a list of the 15 most popular emotional tags in Subject Line Advisor:

Have you tried a variety of emotions? Test out new subject lines using Subject Predict in Design Tracker.

Use Subject Predict to test as many subject lines as you'd like. A new campaign test is not necessary to use Subject Predict; just click in to any existing test in Design Tracker to access this feature.

Once you are in the test campaign, just type in your subject and hit Predict.

From there, you will see a detailed prediction of how your subject line will perform compared to an industry average.

Alter the industry type and sending domain by clicking the underlined values. Viewing results in a different industry may provide additional guidance on your subject line tests.

The Persado emotional tag will appear above your test subject line. Click the underlined section for suggested wording that may increase the projected open rate.

Bonus tip: Try using subject predict to create a catchy preview text phrase.

Previews show how the message appears in different email clients.

Have fun, experiment, and enjoy your results!

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