---
schema_version: "1"
id: a54c2ae4fa28a03fe1b065b4c43be9f7ab2ac93dba110b941bb7483436e66e9b
title: Test a Subject Line Before You Send
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mc_anb_einstein_copy_insights_test_subject_line.md
canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mc_anb_einstein_copy_insights_test_subject_line.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 8f011b0252d493763de7ea31f04aae9b9e4953c96962245aa063cda4703498b3
description: Find out how your message’s subject line is likely to influence message performance. Test the performance of a single message or compare up to 10 subject lines.
products:
  - Marketing
  - Marketing Cloud Intelligence
release: "264"
---
# Test a Subject Line Before You Send

Find out how your message’s subject line is likely to influence message performance. Test the performance of a single message or compare up to 10 subject lines.

Einstein evaluates the subject lines as they appear in your subscriber’s inbox, and tests the subject line for potential bias.

**Interpreting Test Results**

To help you understand how the predicted performance compares to your own past performance in a business unit, contextual analytics appear.

1. On the Einstein Copy Insights dashboard, enter a subject line with up to 80 characters in the Performance Tester input field.
2. Click **Test**.
    
    The Einstein performance prediction and contextual analytics appear, indicating a predicted engagement rate range, most likely engagement rate, and past performance.
3. To see a new prediction, modify the subject line and click **Test**.
    
    Contextual analytics appear to help you understand how the predicted performance compares to your own past performance within a business unit.
    
      
    | Graphic Indicator | Engagement Rate Factor | Description |
    | --- | --- | --- |
    | Purple dotted line | Average Engagement Rate | Unweighted 90-day average engagement rate (engagement rate mean) of all commercial sends to at least 30 recipients in your business unit |
    | Amber shaded area | Predicted Engagement Rate Range | Distribution of possible engagement rates based on your past sends, global data, and the Einstein model’s confidence for your enterprise (EID) |
    | Amber dotted line | Predicted Engagement Rate | Predicted most likely engagement rate |
    | Blue lines | Other subject lines and subject line groups | Performance distribution for subject lines or subject lines groups from the past 90 days |
    
    After the contextual analytics, the most impactful language factors appear and show how much they influence the prediction. Use these factors to adjust your subject lines.
    
    ![Important](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-mktg-mc_data_management_and_analytics-264-0-0-production-enus/7988f60d-cd94-4b42-8836-dc11773564b5/images/icon_important.png)
    
    Important Predicted performance factors and guidance are unique for each subject line that you test. Don't generalize the guidance or use it as a standard for best practices.
    
    These factors are used to measure subject line performance. We show the top five most impactful factors for each tested subject line.
    
    - Number of numeric symbols
    - Number of emoji symbols
    - Ratio of uppercase characters
    - How unique and original the subject line is
    - Number of question marks
    - Number of exclamation marks
    - Number of dollar symbols
    - Number of percentage symbols
    - Number of time-sensitive words and phrases
    - The degree of personalization
    - Word count
    - Character length
    - Contains specific keywords