Dark Mode Preview

How it works

When you preview an email, Emailens automatically generates simulated dark mode variants for each client that supports it. The simulation applies the same CSS transformations that each email client uses, rendered in Chromium. Actual rendering in native email clients may differ slightly due to engine-specific quirks.

• Gmail iOS — applies full color inversion (inverts both light and dark colors)
• Gmail Android — applies partial color inversion (inverts only extreme colors)
• Gmail Web — only darkens the UI chrome; email content is not modified
• Outlook 365 — applies its own dark theme with partial color adjustments
• Outlook (New) — applies partial color inversion (same as Outlook 365)
• Outlook Classic — applies full color inversion in dark mode
• Apple Mail — respects prefers-color-scheme: dark media queries; falls back to partial inversion if absent
• Yahoo Mail — only darkens the UI chrome; email content is not modified
• Samsung Mail — respects prefers-color-scheme: dark; falls back to partial inversion if absent
• Thunderbird — respects prefers-color-scheme: dark (v140+); falls back to full inversion if absent

Viewing dark mode variants

In the preview results, each client tab has a Light / Dark toggle. Switch to dark mode to see the simulated rendering.

Dark mode warnings

The analysis includes dark-mode-specific warnings when your email may not look correct after transformation:

• Hardcoded dark background colors that become invisible in dark mode
• Images with transparent backgrounds that lose contrast
• Text colors that are too close to the inverted background

Making emails dark-mode friendly

See the Dark Mode Guide for best practices on writing HTML emails that render well in both light and dark mode.