Question 1

What is the Css Inliner tool used for?

Accepted Answer

The Css Inliner tool helps email designers and developers build, preview, and test HTML emails across different rendering environments. HTML email requires a different approach to web development — email clients like Outlook use Word's rendering engine, which has limited CSS support. This tool accounts for those constraints, helping you identify issues before sending to real recipients.

Question 2

Why does my HTML email look different in Outlook vs Gmail?

Accepted Answer

Outlook (2007-2021) uses Microsoft Word's HTML rendering engine, which has extremely limited CSS support — it ignores flexbox, CSS grid, CSS animations, and many modern properties. Gmail and Apple Mail use more capable rendering engines. This is why HTML emails use table-based layouts, inline styles, and VML for Outlook-specific features. Use our HTML Email Preview to see how your email renders across different clients before sending.

Question 3

Should I inline CSS in HTML emails?

Accepted Answer

Yes — CSS should be inlined (written directly in style="" attributes) for HTML emails. Many email clients, especially Gmail, strip

Question 4

What HTML elements are safe to use in emails?

Accepted Answer

Email-safe HTML relies on table-based layouts, inline styles, and basic elements: , ,

, , ,

,
, , , . Avoid

for layout (unreliable in Outlook), flexbox, CSS grid, JavaScript (blocked by all clients), web fonts (fallback to system fonts), SVG (poor support), and background-image in CSS (use bgcolor attribute instead). Use our HTML Email Preview to test compatibility.

Kostenloses Css Inliner-Tool

Original HTML with <style>

Inlined Output