Email Client Support Table
What Gmail, Outlook, Apple Mail, Yahoo, Samsung Mail and Thunderbird support in HTML email, from caniemail’s device tests, with the date each was last tested.
A support table for the mail clients that matter here, taken from caniemail — tests run on real devices, each with the date it was last run. It also shows where the data stops: the Korean webmail providers have no public test data, so their columns are empty rather than filled in by resemblance.
🔒 Runs entirely in your browseremailhtmlcompatibilityreference
120 features
Legend: Supported · Partial · Not supported · Not verified
| Gmail (web) | Gmail (iOS app) | Gmail (Android app) | Outlook for Windows (desktop) | Outlook.com (web) | New Outlook for Windows↩ | Apple Mail (macOS) | Mail (iOS) | Yahoo! Mail (web) | Samsung Email (Android) | Thunderbird | Naver MailNot verified | Daum / HanmailNot verified | Kakao MailNot verified | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AMP for Emaillast tested 2020-03-31 | Supported | Supported | Supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| BIMIlast tested 2022-12-29 | Supported | Supported | Supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| accent-colorlast tested 2023-12-19 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| align-itemslast tested 2023-12-19 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| animationlast tested 2026-04-07 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not supported | Not verified | Not verified | Not verified |
| aspect-ratiolast tested 2023-12-19 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| @font-facelast tested 2023-12-19 | Not supported | Not supported | Not supported | Partial | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| @importlast tested 2019-02-28 | Not supported | Not supported | Not supported | Supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| @keyframeslast tested 2021-05-25 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| @media (-webkit-device-pixel-ratio)last tested 2019-08-20 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Not supported | Not verified | Not verified | Not verified |
| @media (hover), @media (any-hover)last tested 2022-08-29 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| @media (orientation)last tested 2019-08-20 | Supported | Not supported | Supported | Not supported | Supported | Supported | Supported | Partial | Not supported | Supported | Not supported | Not verified | Not verified | Not verified |
| @media (prefers-color-scheme)last tested 2023-03-08 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Not supported | Not verified | Not verified | Not verified |
| @media (prefers-reduced-motion)last tested 2021-02-20 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Not supported | Not verified | Not verified | Not verified |
| @medialast tested 2023-12-13 | Partial | Partial | Partial | Not supported | Partial | Partial | Supported | Supported | Partial | Partial | Not supported | Not verified | Not verified | Not verified |
| @supportslast tested 2020-05-25 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Not verified | Not verified | Not verified |
| backdrop-filterlast tested 2024-01-17 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| background-blend-modelast tested 2019-02-28 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-cliplast tested 2019-02-28 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-colorlast tested 2019-02-28 | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-imagelast tested 2023-07-24 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| background-originlast tested 2019-02-28 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-positionlast tested 2019-02-28 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-repeatlast tested 2019-02-28 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| background-sizelast tested 2019-02-28 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| backgroundlast tested 2023-07-24 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| block-size & inline-sizelast tested 2022-07-14 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| border-collapselast tested 2023-12-20 | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| border-imagelast tested 2019-02-28 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| border-inline & border-block individual logical propertieslast tested 2022-07-14 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Not verified | Not verified | Not verified | Not verified |
| border-inline & border-block longhand propertieslast tested 2022-07-14 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| border-inline & border-blocklast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not verified | Not verified | Not verified | Not verified |
| border-radius logical propertieslast tested 2022-08-16 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not verified | Not verified | Not verified | Not verified |
| border-radiuslast tested 2021-03-09 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| border-spacinglast tested 2023-12-20 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| borderlast tested 2021-07-22 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| box-shadowlast tested 2023-12-20 | Not supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| box-sizinglast tested 2019-02-28 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| caption-sidelast tested 2021-05-13 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| clearlast tested 2024-09-06 | Supported | Supported | Partial | Not supported | Supported | Supported | Supported | Supported | Partial | Supported | Not verified | Not verified | Not verified | Not verified |
| clip-pathlast tested 2021-03-09 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| color-scheme CSS propertylast tested 2023-09-18 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| column-countlast tested 2019-02-28 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| css column propertieslast tested 2022-08-02 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| CSS commentslast tested 2024-04-25 | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| conic-gradient()last tested 2023-01-02 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| cursorlast tested 2025-07-02 | Not supported | Not supported | Not supported | Not verified | Not supported | Not supported | Partial | Not supported | Partial | Not verified | Supported | Not verified | Not verified | Not verified |
| directionlast tested 2021-10-05 | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| display:flexlast tested 2021-11-02 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| display:gridlast tested 2019-02-28 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| display:nonelast tested 2019-02-28 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| displaylast tested 2021-12-01 | Supported | Partial | Partial | Partial | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| empty-cellslast tested 2024-08-23 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified | Not verified |
| filterlast tested 2024-01-03 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| flex-direction:columnlast tested 2023-01-17 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| flex-wrap: wraplast tested 2023-01-16 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| floatlast tested 2024-05-08 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| font-kerninglast tested 2022-08-01 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| font-size-adjustlast tested 2026-04-16 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Partial | Not verified | Supported | Not verified | Not verified | Not verified |
| font-sizelast tested 2024-02-28 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Partial | Partial | Supported | Not verified | Not verified | Not verified |
| font-stretchlast tested 2023-09-23 | Supported | Supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Not supported | Supported | Not verified | Not verified | Not verified |
| font-weightlast tested 2022-06-23 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| font shorthandlast tested 2019-02-28 | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| clamp()last tested 2021-05-07 | Supported | Partial | Partial | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| light-dark()last tested 2024-08-14 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| max()last tested 2021-05-07 | Supported | Partial | Partial | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| min()last tested 2021-05-07 | Supported | Partial | Partial | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| gap, column-gap, row-gaplast tested 2022-12-28 | Partial | Partial | Partial | Not supported | Partial | Partial | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| grid-template-* propertieslast tested 2023-01-09 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| height propertylast tested 2019-09-27 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| hyphenate-characterlast tested 2024-06-19 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| hyphenate-limit-charslast tested 2024-08-08 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| hyphenslast tested 2022-08-03 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| !important keywordlast tested 2021-11-30 | Partial | Partial | Partial | Partial | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| inertlast tested 2026-04-16 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| inline-size last tested 2019-02-28 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| insetlast tested 2024-05-29 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Supported | Not verified | Not verified | Not verified |
| fit-content, min-content, max-contentlast tested 2022-12-31 | Supported | Partial | Supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Not supported | Supported | Not verified | Not verified | Not verified |
| justify-contentlast tested 2021-03-09 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| left, right, top, bottomlast tested 2021-05-16 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| letter-spacinglast tested 2020-01-19 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| line-heightlast tested 2021-10-02 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| linear-gradient()last tested 2021-12-29 | Supported | Supported | Partial | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| list-style-imagelast tested 2020-04-20 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| list-style-positionlast tested 2020-04-20 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| list-style-typelast tested 2020-04-20 | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| list-stylelast tested 2020-04-20 | Partial | Partial | Partial | Partial | Supported | Supported | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| margin-block-start & margin-block-endlast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| margin-inline & margin-blocklast tested 2022-07-12 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Supported | Not verified | Not verified | Not verified |
| margin-inline-start & margin-inline-endlast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| marginlast tested 2019-10-01 | Partial | Partial | Partial | Partial | Partial | Partial | Supported | Supported | Partial | Supported | Supported | Not verified | Not verified | Not verified |
| mask-imagelast tested 2024-11-27 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| max-block-sizelast tested 2022-09-01 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| max-height propertylast tested 2021-11-29 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| max-inline-sizelast tested 2024-05-31 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| max-widthlast tested 2019-08-02 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| min-block-sizelast tested 2024-05-31 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| min-height propertylast tested 2021-11-29 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| min-inline-sizelast tested 2022-08-30 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| min-width propertylast tested 2021-11-29 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| mix-blend-modelast tested 2020-12-12 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| lch(), oklch(), lab(), oklab()last tested 2023-01-18 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not supported | Not verified | Not verified | Not verified |
| CSS Nestinglast tested 2023-08-31 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Partial | Supported | Not supported | Partial | Supported | Not verified | Not verified | Not verified |
| object-fitlast tested 2021-07-15 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| object-positionlast tested 2021-07-15 | Supported | Partial | Partial | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| opacitylast tested 2019-02-28 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| orphanslast tested 2024-06-13 | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| outline-offsetlast tested 2022-12-26 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Supported | Not verified | Not verified | Not verified |
| outlinelast tested 2022-03-17 | Supported | Supported | Supported | Not supported | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| overflow-wraplast tested 2022-08-03 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| overflowlast tested 2025-05-27 | Partial | Partial | Partial | Not supported | Partial | Partial | Partial | Partial | Partial | Partial | Supported | Not verified | Not verified | Not verified |
| padding-block-start & padding-block-endlast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| padding-inline & padding-blocklast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Not supported | Not verified | Not verified | Not verified | Not verified |
| padding-inline-start & padding-inline-endlast tested 2022-07-13 | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified | Not verified |
| paddinglast tested 2019-07-25 | Supported | Supported | Supported | Partial | Supported | Supported | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| positionlast tested 2021-05-16 | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Partial | Partial | Partial | Partial | Supported | Not verified | Not verified | Not verified |
| :activelast tested 2019-10-28 | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Partial | Not supported | Supported | Not supported | Supported | Not verified | Not verified | Not verified |
| :checkedlast tested 2020-03-10 | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
| :defaultlast tested 2026-02-05 | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Supported | Supported | Supported | Not verified | Supported | Not verified | Not verified | Not verified |
| :first-childlast tested 2019-10-16 | Not supported | Not supported | Not supported | Not supported | Partial | Partial | Supported | Supported | Supported | Supported | Supported | Not verified | Not verified | Not verified |
Support data from caniemail (MIT, © Rémi Parmentier), vendored at a pinned commit. Each verdict is a test caniemail ran on a real device — this site owns no rendering farm and runs none of them.
Naver, Daum and Kakao — No public test matrix covers the Korean webmail providers, so their columns are empty rather than guessed. An empty column means "nobody has measured this", which is a different thing from "does not work".
How to use it
Search in English
The underlying data is caniemail’s and is written in English, so `flex`, `background-image` and `prefers-color-scheme` find things and their Korean names do not.
Read the cell and its date
Hovering a cell gives the verdict in words, caniemail’s footnote where there is one, and when it was tested. A verdict from 2019 about a webmail is a weaker claim than one from last year, and the date is how you tell.
Treat an empty cell as unmeasured
“확인되지 않음” means nobody has published a test, not that the feature fails. The three Korean clients are entirely in that state, and one borrowed column (new Outlook) is marked as borrowing outlook.com’s data.
Common questions
Why are Naver and Kakao empty?
Because no public matrix tests them and this site has no way to. Filling those columns from what a similar webmail does would produce confident rows that nobody checked, and a wrong row about Naver would do more damage here than an empty one — this is the audience most likely to act on it.
Where does the data come from and how fresh is it?
From caniemail (MIT, © Rémi Parmentier), vendored at a pinned commit that the generated file records. It is refreshed by re-running the generator and reading the diff — deliberately not fetched live, so a claim on this page is reproducible from the commit that made it.
Partial support — what does it actually mean?
That the feature works with a caveat caniemail recorded: a value that is ignored, an element it only applies to, a version that behaves differently. The footnote in the cell is that caveat, and it is usually the thing you needed to know.
Feed it from
HTML Email Compatibility Check
Checks an email’s HTML against what each mail client actually supports, points at the element that breaks, and shows what survives Gmail, Outlook and the rest side by side.
Runs entirely in your browser
HTML Email Builder
Builds an email from blocks as table-based, inline-styled HTML with a VML-backed button, and writes the plain-text alternative from the same blocks.
Runs entirely in your browser
Next
These accept what this tool produces, so the result can go straight in.
Sent vs Delivered Comparison
Send a draft to a disposable address from your own account and see what the sending path rewrote — links wrapped in redirects, dropped style blocks, added beacons, the encoding used.
Uses our server
HTML Email Builder
Builds an email from blocks as table-based, inline-styled HTML with a VML-backed button, and writes the plain-text alternative from the same blocks.
Runs entirely in your browser
HTML Email Compatibility Check
Checks an email’s HTML against what each mail client actually supports, points at the element that breaks, and shows what survives Gmail, Outlook and the rest side by side.
Runs entirely in your browser
CORS Tester
Sends the preflight a browser would send from a chosen origin plus a GET with that Origin, and explains by the Fetch standard’s rules exactly which header blocked it.
Uses our server
CSV Cleaner
Trims cells, normalises headers, fixes number and date formats and reports rows with the wrong column count.
Runs entirely in your browser
CSV Join
Joins two tables on a key column with inner, left, right or outer semantics and shows unmatched rows.
Runs entirely in your browser