Free tool
Responsive email checker
Paste your email’s HTML to see it on a phone, a tablet and a desktop, in light and dark mode. We also check the code for the things that break layouts on small screens.
Dark preview uses a full colour flip, which is what the Gmail and Outlook apps do to emails without dark-mode styles. Apple Mail only changes emails that ask for it.
Looks right? Check it won’t land in spam before you send.
Run a spam test