Q: What is a CSS inliner?

A CSS inliner moves your external or -block CSS rules directly into each HTML element's inline style attribute. This is essential because email clients like Gmail, Yahoo Mail, and Outlook strip or ignore tags and linked stylesheets, causing your emails to render unstyled without inlining.

Question 1

What is a CSS inliner?

Accepted Answer

A CSS inliner moves your external or

Question 2

Why do I need to inline CSS for emails?

Accepted Answer

Most email clients — including Gmail Web, Gmail Android/iOS, Yahoo Mail, and Outlook.com — remove or partially ignore <style> tag contents. Inlining CSS guarantees your styles are applied regardless of the email client, because inline styles have the highest CSS specificity and can't be stripped by the client.

Question 3

Does the RenderOps CSS inliner upload my email code?

Accepted Answer

No — the CSS inliner runs 100% in your browser using JavaScript. Your HTML code never leaves your device, is never sent to any server, and is never stored. It works even without an internet connection once the page has loaded.

Question 4

Does CSS inlining work for Outlook emails?

Accepted Answer

Yes. Inlining CSS is particularly important for Outlook emails, as Outlook 2013–2021 uses the Microsoft Word rendering engine which strips non-inline styles. After inlining, you should also use the RenderOps Retrofit tool to convert any Flexbox or CSS Grid layouts into nested HTML tables for full Outlook compatibility.

Question 5

What is the best free CSS inliner for email?

Accepted Answer

RenderOps offers a free, specificity-aware CSS inliner that resolves the full CSS cascade before inlining, correctly handles selector priority (IDs > classes > tags), and preserves @media queries and :hover rules in a clean <head> style block so your responsive layouts continue to work.

Question 6

What happens to @media queries after CSS inlining?

Accepted Answer

The RenderOps CSS inliner preserves @media queries, @font-face rules, and pseudo-class selectors like :hover in a clean

Question 7

Can I use a CSS inliner with Mailchimp or Klaviyo templates?

Accepted Answer

Yes. You can export your HTML template from Mailchimp or Klaviyo, run it through the RenderOps CSS inliner, then re-import or paste the inlined code back. This is especially useful for custom-coded templates that use internal <style> blocks.

CSS Inliner for Email