Can I email…?
Look up whether a CSS property or HTML element actually works in email. Search any feature to see its support (Yes, Partial or No) across Gmail, Outlook, Apple Mail and 18 more clients, with a plain-English verdict.
Try one:
Frequently asked questions
What can I look up?
Any CSS property or value (like display:flex, border-radius, position:absolute) or HTML element (like <video>, <picture>, <style>). Start typing and pick from the suggestions to see a support breakdown across all 21 clients we track.
What do 'partial' and 'unknown' mean?
Partial means the client supports the feature with caveats: it may work only in some contexts, or need a fallback. Unknown means we don't have a confident data point for that client and feature pairing yet. Full support (Yes) means it renders as expected, and No means it's dropped or ignored.
Why does Outlook fail so many features?
Outlook on Windows renders with Microsoft Word, not a browser engine, so it ignores flexbox, grid, border-radius, background gradients and much of modern CSS. That's why so many properties show 'No' for Outlook, and why table-based layouts and VML fallbacks are still standard for email.
How do I check a whole email at once?
This tool looks up one feature at a time. To audit an entire email, paste your HTML into the CSS compatibility checker. It runs every property through the same data and gives you a per-client score plus copy-paste fixes for what breaks.