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Email Preheader Generator
Write your preview text, watch it render next to your subject line in Gmail, Apple Mail, Outlook and Yahoo at the widths those clients actually cut at, then copy the hidden preheader HTML for your email. It is free, there is no account, and nothing you type leaves your browser.
Start from an example
Preheader score
Length
Enter preheader text
Inbox previews
Gmail (desktop) · ~100 chars
Gmail (mobile) · ~40 chars
Your Brand
9:41 AMYour subject line
Your preheader text appears here...
Apple Mail (desktop) · ~90 chars
Your Brand
9:41 AMYour subject line
Your preheader text appears here...
Apple Mail (iPhone) · ~100 chars
Your Brand
9:41 AMYour subject line
Your preheader text appears here...
Outlook (desktop) · ~50 chars
Your Brand
Your subject line
Your preheader text appears here...
Yahoo Mail · ~110 chars
Struck-through text is the part that client cuts. Widths vary with window size, font settings and how long your subject line is, so treat these as the working budget rather than a guarantee.
Issues detected
Spam trigger words detected
Your preheader restates the subject line. That is the only other line of copy you get in the inbox, so use it to say something new.
This looks like a view-in-browser link. That is the text an inbox grabs when nothing else is set, and it earns no opens.
Excessive capitalization may trigger spam filters
Excessive punctuation (!! or ???) may look spammy
Enter preheader text to check for issues
Suggestions
- Enter preheader text to get suggestions
How to use the preview text generator
Three steps, about a minute, and you can do it for every send.
-
1
Paste your subject line
The previewer needs it to show the pairing the way the inbox does, and to tell you when your preheader is only restating what the subject already said.
-
2
Write the preheader
Aim for 40 to 130 characters with the point in the first 40. Watch the struck-through tail in each preview to see what Gmail on a phone throws away.
-
3
Copy it into your email
Use the text on its own if your platform has a preview text field, or copy the generated hidden preheader block if you send hand-written HTML.
What preheader text is
Every inbox shows three things before anyone decides to open: who sent it, the subject line, and a short run of text after or under it. That third piece is the preheader, also called preview text. It comes from the first readable text the client finds in your email body.
If you never set it, the client takes whatever is there. That is why so many campaigns land in the inbox reading "View this email in your browser" or a stray merge tag. Somewhere between 40 and 130 characters of prime inbox real estate goes to a housekeeping link.
Setting it yourself turns that line into a second headline. The subject line makes the claim; the preheader gives the reason to believe it. A subject that reads "Scheduling is here" does more work when the line under it reads "Queue a broadcast for Tuesday 9am, pick the timezone, and walk away."
This page is both a preheader generator and an email preheader previewer: it writes the hidden HTML block, and it shows you the result at the truncation points of the six clients most lists are made of.
Preview text best practices
Front-load the point
Gmail on a phone gives you about 40 characters, and that is where most of your list reads. Put the number, the deadline or the name of the thing in the opening words. Everything after character 40 is a bonus for desktop readers, not the place for your payoff.
Write 40 to 130 characters
Under 40 and the client backfills the gap with body copy you did not choose. Over 130 and the tail is cut everywhere but the widest desktop windows. The range holds up across Gmail, Apple Mail, Outlook and Yahoo without writing a different line for each.
Continue, do not repeat
The two lines are read together, so treat them as one sentence broken in half. If the subject asks a question, the preheader hints at the answer. If the subject names an offer, the preheader names the catch, the deadline or the proof. Repeating the subject wastes half your inbox copy.
Hide it properly
A preheader belongs in the inbox, not at the top of the opened email. Hide the block with
display:none, max-height:0 and
mso-hide:all, and pad it with zero-width characters so no body
copy leaks in behind it. The generated code above does all three.
Preview text character limits by email client
| Email client | Preview text visible | Notes |
|---|---|---|
| Gmail (desktop) | ~100-140 characters | Shares one row with the subject, so a long subject eats the preheader |
| Gmail (mobile) | ~35-40 characters | The tightest view, and usually the biggest slice of a list |
| Apple Mail (desktop) | ~80-90 characters | Shows on its own line under the subject |
| Apple Mail (iPhone) | ~75-100 characters | Two lines by default, one if the preview setting is changed |
| Outlook (desktop) | ~35-50 characters | Reading pane position changes the budget |
| Outlook (mobile) | ~40-50 characters | Close to the desktop app |
| Yahoo Mail | ~100-110 characters | One of the more generous clients |
These are working ranges, not fixed limits. Window width, font size, display density and subject line length all move the cut-off, which is why writing to the 40-character mobile budget is the safe habit.
Email preheader examples
Six subject and preheader pairs where the second line adds something. Click any of them at the top of the page to load it into the generator and edit from there.
Newsletter
The 5 deliverability myths that cost you opens
Plus the inbox test we run before every send, and what it caught last week.
75 characters
Product launch
Scheduling is here
Queue a broadcast for Tuesday 9am, pick the timezone, and walk away. Takes a minute.
84 characters
Abandoned cart
You left the Nomad jacket behind
Still in your size, still in your cart. We hold it for 24 more hours.
69 characters
Webinar invite
Thursday: self-hosting email without the pager
Live walkthrough at 11am ET, 30 minutes, recording sent to everyone who signs up.
81 characters
Onboarding
Your account is ready
Start with the import wizard, then send yourself a test. Both take under five minutes.
86 characters
Re-engagement
Should we stop emailing you?
No hard feelings either way. One click keeps you on the list, one click ends it.
80 characters
Where to set preview text in your email platform
Most platforms have a field for it. If yours does, use the field and skip the HTML.
Mailchimp
Campaign setup, under the subject line. The field is labelled Preview text.
Klaviyo
Campaign content step, in the same panel as the subject line and sender details.
HubSpot
The Settings tab of the email editor, directly under Subject line.
Brevo and ActiveCampaign
Both put it in the campaign settings step next to the subject line.
Broadcast
Every broadcast and campaign email has a preheader field beside the subject line, and the editor shows the inbox pairing as you type.
Hand-written HTML or Amazon SES
No field, so use the hidden block this tool generates. It goes first inside the body tag, above the view-in-browser link.
Email preheader questions
- What is preheader text in an email?
- Preheader text is the short line of copy an inbox shows next to or under your subject line before anyone opens the message. It comes from the first readable text in the email body, which is why an email with no deliberate preheader often shows "View this email in your browser" or a run of merge-tag junk. Setting it yourself turns roughly 40 to 130 wasted characters into a second headline.
- Is preheader text the same as preview text?
- Yes. Preheader, preview text, Johnson box and snippet text all describe the same line of copy. Email platforms differ on the label: Mailchimp and Klaviyo call it preview text, Salesforce and many HTML developers call it the preheader, and Gmail calls it the snippet. This generator produces the same thing whichever name you use for it.
- How long should email preview text be?
- Aim for 40 to 130 characters. Gmail on a phone shows roughly 35 to 40 characters, Outlook desktop about 35 to 50, Apple Mail around 80 to 90, and Gmail on desktop up to 140 when the subject line is short. Front-load the part that has to land in the first 40 characters and treat everything after that as a bonus for desktop readers.
- How do I add preheader text to an HTML email?
- Put a hidden element as the first thing inside the body tag, holding your preview text followed by padding characters, then style it with display:none, max-height:0 and overflow:hidden so it never renders in the opened email. This tool writes that block for you, including the zero-width non-joiner padding that stops clients from pulling body copy in behind your text. If your platform has a preview text field, use the field instead and skip the HTML entirely.
- Why does my email show "View this email in your browser" in the inbox?
- Because that link is the first readable text in your HTML, so the inbox grabs it as the snippet. Move the view-in-browser link below a hidden preheader block, or set the preview text field in your sending platform. Either fix reclaims the line.
- Should I repeat my subject line in the preheader?
- No. A preheader that repeats the subject burns the only other piece of copy you get in the inbox. Use it to add the detail the subject left out: the deadline, the number, the name of the thing, the reason it matters now. This tool flags a preheader that duplicates or merely restates the subject line.
- Can I use emojis in preview text?
- You can, and they render in every major client, but they eat the space you have and some corporate Outlook installs still fall back to a box glyph. One emoji at most, never as a load-bearing part of the message. This previewer counts emoji as the single character a person sees rather than the two code units JavaScript sees, so the character count matches what the inbox truncates.
- Does preheader text affect deliverability?
- Indirectly. Spam filters read the preheader like any other copy, so a line stacked with urgency and money words raises your risk alongside the subject line. The larger effect is on engagement: a preheader that earns opens and avoids complaints builds the sending reputation that keeps you out of the promotions tab.
- Is this email preheader previewer free?
- Yes. It is free, there is no signup, and nothing you type leaves your browser. The analysis, the inbox previews and the generated HTML all run locally on this page.
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