01
Lead with benefit62 chars
See the three sends, two audience segments, and goal for each.
0% subject overlapNo mechanical flags
100/100
All tools
WRITING SYSTEM / SUBJECT SEQUEL / LOCAL GENERATIONWrite the second line,
Write the second line,
not the same line twice.
Turn a campaign brief into subject-aware preview-text options, inspect the reasoning, then export implementation HTML and a complete test manifest.
- Local and deterministic
- Pair diagnostics
- HTML + JSON + CSV
Generated set / round 1
Ten different jobs for the second line.
Scores diagnose mechanics, not predicted opens. Read every option for truth, tone, and message fit.
02
Add specificity30 chars
Review the plan before Friday.
25% subject overlapNo mechanical flags
100/100
03
Benefit + condition92 chars
See the three sends, two audience segments, and goal for each—review the plan before Friday.
25% subject overlapNo mechanical flags
100/100
04
Detail + action55 chars
Review the plan before Friday. Open your campaign plan.
50% subject overlapNoticeable subject repetition
87/100
05
Action first90 chars
Open your campaign plan for see the three sends, two audience segments, and goal for each.
50% subject overlapNoticeable subject repetition
87/100
06
Inside the message70 chars
Inside: see the three sends, two audience segments, and goal for each.
0% subject overlapNo mechanical flags
100/100
07
Audience context60 chars
A useful next step for growth team: open your campaign plan.
50% subject overlapNoticeable subject repetition
87/100
08
Question33 chars
Ready to open your campaign plan?
75% subject overlapMostly repeats the subject
72/100
09
Reassurance98 chars
See the three sends, two audience segments, and goal for each, with review the plan before Friday.
25% subject overlapNo mechanical flags
100/100
10
Subject sequel93 chars
See the three sends, two audience segments, and goal for each. Review the plan before Friday.
25% subject overlapNo mechanical flags
100/100
Selected draft
Edit the words. Keep the evidence.
The draft remains editable after selection so the generator is a starting point, not an approval system.
100mechanical score
0%subject overlap
See the three sends, two audience segments, afirst characters
Checks to review
No mechanical warnings found.
Useful signals
Concise enough to front-load
Adds vocabulary beyond the subject
Contains a complete reader-facing thought
Meaningful copy begins immediately
Width scenarios, not client promises
Northstar Wide inbox
Your July campaign plan is ready — See the three sends, two audience segments, and goal for each.
Northstar Compact inbox
Your July campaign plan is ready — See the three sends, two audience segments, and goal for each.
Northstar Mobile inbox
Your July campaign plan is ready — See the three sends, two audience segment…
Client, device, font, sender length, subject length, and user settings can all change what is visible. Send real tests.
Hidden preheader HTML
<div style="display:none!important;mso-hide:all;max-height:0;max-width:0;opacity:0;overflow:hidden;visibility:hidden;font-size:1px;line-height:1px;color:transparent;" aria-hidden="true">
See the three sends, two audience segments, and goal for each.
</div>Handoff package
Keep the brief, generated variants, diagnostics, and selected copy together for review and testing.
Subject creates the frame. Preview text adds the next useful fact.
Preview text is the snippet many inboxes display near the sender and subject. If a sender does not intentionally supply it, clients can pull the first available message content—sometimes navigation, a browser-view link, or accessibility text that was never written for the inbox.
No single character count is universally safe. Available space changes with client, viewport, font, subject length, sender length, and user settings. Front-load the information that matters and treat every visualization as directional.
Give the second line a different job.
Make the primary promise or required action understandable on its own.
Supply a deadline, condition, proof point, next step, or reassuring detail.
The opened message must support the pair without bait-and-switch language.
The tool measures repeated meaningful words and basic copy mechanics. A low overlap score does not make a sentence true, on-brand, compliant, or effective. Human review remains necessary.
Put intended text first, then test the complete message.
The exported snippet uses a visually hidden span intended to appear near the start of the email body. It includes common hiding properties and an Outlook-oriented mso-hide declaration. Your email platform may already provide a dedicated preview-text field; prefer its supported implementation when available.
Do not assume the hidden span is invisible everywhere merely because it disappears in a web preview. Email clients have different rendering engines and can transform markup. Test the actual compiled email after templates, merge tags, CSS inlining, and provider processing.
A preview-text test is a pair test.
Keep the subject, sender, audience, send time, and body constant when isolating preheader copy. Randomize recipients, check sample balance, choose the primary metric before sending, and avoid selecting a winner from a tiny early difference.
Open tracking is incomplete and can be distorted by privacy protections, image proxying, blocking, and automated activity. When possible, connect the inbox test to a downstream action that reflects the email's purpose.
Plan an A/B testEmail preheader generator FAQ.
Is preheader the same as preview text?+
People often use the terms interchangeably. In some templates, preheader also refers to a visible region at the top of the email, while preview text specifically means the inbox snippet. Confirm how your platform uses each term.
How long should preview text be?+
There is no universal client limit. Put the most important new information first, keep the sentence concise, and test the final message across the inboxes and devices that matter to your audience.
Should it repeat the subject line?+
Usually no. Repetition spends limited inbox space without adding information. Use the second line for a deadline, condition, benefit, consequence, next action, or clarification.
What happens if I leave it blank?+
An inbox can extract the first available text from the message body. That might be useful content, or it might be navigation, a browser-view link, image alt text, or another accidental fragment.
Does hidden preheader HTML work everywhere?+
No implementation is universal. Platforms and clients compile, sanitize, and render email differently. Use your provider's supported preview-text field when available and send real tests after the final build.
Does a higher score predict more opens?+
No. The score only evaluates disclosed mechanical checks such as length range, subject-word overlap, punctuation, capitalization, and accidental boilerplate. It is not a performance forecast.
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