Build and Check HTML Email

These tools help you make an email and check its HTML. Build one from blocks or a template, validate its size, CSS and links, preview dark mode, and work out widths, banner sizes and font sizes.

Tools in this group

• Dark Mode Email Checker — Paste your email's HTML to see it in light mode and simulated dark modes, find what breaks and copy the code that helps.
• Email Banner Sizes Calculator — Choose the width of your email and the shape of the banner to get the exact image size to export and the HTML attributes to use.
• Email Font Size Preview — Compare web-safe fonts and text sizes on desktop and phone widths, then copy the styles for your email's body text and headings.
• Email Footer Generator — Enter your company details, unsubscribe link and legal text to get a newsletter footer as HTML and plain text.
• Email HTML Validator — Paste the HTML of an email, or open the file, to check size, CSS support, images, links and structure before you send.
• Email Template Size Calculator — Set the email width, padding and columns to get every content and image width, or paste an email's HTML to check its sizes.
• HTML Email Builder — Add and reorder blocks, edit the text and colors, and copy the finished email as table-based HTML and plain text.
• HTML Email Template Gallery — Pick a template, add your brand color, logo and company details, then copy the HTML or open it in the builder.