Free Tool

Email Preview Tool

The complete HTML email preview tool. Test your email subject line preview, preview text in email, and full HTML email rendering across Gmail, Outlook, and Apple Mail — on desktop and mobile.

Inbox Metadata

0
0

Recommended: 85–140 characters. Shorter subjects allow more preview text to show.

HTML Email Body

Preview Options

100%

0
Subject Chars
0
Preview Chars
Low
Spam Risk
Inbox Row Preview — how recipients see your email
A
Acme Corp
Your subject line here… — The snippet shown below the subject…
10:42 AM
A
Acme Corp
10:42
Your subject line here…
The snippet shown below the subject…
Gmail — Desktop
How To Use

How to Use the Email Preview Tool

Test your HTML email, subject line, and preview text in four quick steps.

01

Enter Sender Info

Type your sender name and email. The inbox row preview instantly shows how your brand appears in Gmail and on mobile.

02

Write Subject & Preview Text

Enter your email subject line preview text and preheader. Character counters and colour-coded warnings guide you to the optimal length for each email client.

03

Paste Your HTML Email

Drop your HTML email code into the editor. Supports full HTML email preview including inline CSS, tables, and responsive layouts. Plain text mode is also available.

04

Switch Clients & Devices

Toggle between Gmail, Outlook, Apple Mail, and dark mode. Switch between desktop, tablet, and mobile viewports to see exactly how your email looks everywhere.

Why Email Preview Matters

Email preview text — the snippet shown below the subject line in the inbox — is one of the most underused conversion levers in email marketing. Studies consistently show that optimising preview text in email can lift open rates by 10–20%.

Our HTML email preview tool lets you see the complete picture: the inbox row that subscribers see before opening, and the rendered body once they do. You can test across simulated Gmail, Outlook, Apple Mail, and dark mode environments without sending a single test email.

  • Live email subject line preview as you type
  • Inbox row simulation for desktop and mobile
  • HTML email preview with iframe sandboxing
  • Gmail, Outlook, Apple Mail & dark mode simulation
  • Character counter with client-specific guidance
  • Spam risk indicator to catch red-flag words
  • Font scale slider to test accessibility
  • 100% browser-side — your email content never leaves your device
📧
Gmail
Desktop & Mobile Web
📨
Outlook
365 & Desktop
🍎
Apple Mail
macOS & iOS
🌙
Dark Mode
All Clients
📱
Mobile
375px viewport
💻
Desktop
Full-width view
FAQ

Frequently Asked Questions

Common questions about HTML email preview, preview text, and subject lines.

Email preview text (also called preheader text) is the short snippet of text that appears in the inbox beneath or beside the subject line, before the email is opened. Most email clients like Gmail, Apple Mail, and Outlook display 40–140 characters of preview text depending on the screen size. Our email preview tool shows exactly how this text will appear.
Most email clients display between 40 and 78 characters of subject line text on desktop. Mobile devices typically show only 25–40 characters. Our email subject line preview tool counts characters in real time and colour-codes the counter so you stay within the safe range. Aim for 40–60 characters for the best cross-client coverage.
Our HTML email preview simulates the background colour, viewport width, and font scale of each client, giving you a close approximation. However, each email client applies its own CSS rendering engine — Outlook in particular strips many CSS properties. For pixel-perfect testing across all clients, we recommend combining this tool with a send-test service. This tool excels at catching layout, subject, and preview text issues before any sending.
The ideal length for preview text in email is 85–140 characters. Shorter subject lines leave more room for preview text. If you do not set a preheader, email clients will pull the first visible text from your email body — which is often unhelpful filler like "View this email in your browser." Our email preview tool highlights the available character budget dynamically.
Yes. The email preview tool runs entirely in your browser. Your HTML email content, subject line, and preview text are never uploaded to any server. All rendering happens client-side using a sandboxed iframe, so your email data stays completely private.
Add a hidden preheader span right after the opening body tag: <span style="display:none;font-size:0;line-height:0">Your preview text here</span>. Email clients read this text for the inbox snippet but it is invisible to subscribers who open the email. Paste your HTML into our email preview HTML tool to see exactly how it will appear.
The spam risk indicator analyses your subject line for common spam trigger words and patterns — such as "FREE!!!", excessive punctuation, ALL CAPS, and known filter phrases. It rates the risk as Low, Medium, or High to help you refine your subject before sending. It is a heuristic guide, not a guarantee, as actual spam filtering depends on sending reputation, authentication, and many other factors.
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