Samsung Mail email CSS: what breaks, and what to write instead

246 of 300 features work in Samsung Mail · 25 partial · 26 not supported · 3 untested. Of the 246 that work here, 69 work in 6 or fewer of the other 20 clients, so a check that passes here says little about the rest.

Works 246 · Partial 25 · Not supported 26 · Untested 3 · of 300

Samsung · mobile · prefers-color-scheme: works

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No signup · Five clients free, Outlook Classic included · All 21 with an account

The checker needs a computer screen.

See what breaks ↓

Samsung Mail opens with a free account.

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@emailens/engine 0.18.22 · data last changed 10 Nov 2026

Samsung Mail with a Microsoft account

Samsung Mail renders an email differently when the account in the app is a Microsoft address (Outlook, Hotmail, Live). The engine's notes list these features as not working with those accounts:

[command]
Partial. Not supported with Microsoft (Hotmail/Outlook) accounts.
[popover]
Partial. Not supported with Hotmail/Outlook accounts.
@font-face
Not supported when using a Microsoft email address; outlook, live, hotmail, etc.
@media
Partial. Not supported with Hotmail/Outlook accounts.
clamp
Partial. Not supported with Microsoft accounts.
conic-gradient
Partial. Not supported with Hotmail/Outlook accounts.
light-dark
Partial. Not supported with Hotmail/Outlook accounts.
linear-gradient
Partial. Not supported with Hotmail/Outlook accounts.

All 12

max
Partial. Not supported with Microsoft accounts.
min
Partial. Not supported with Microsoft accounts.
nesting
Partial. Not supported with Hotmail/Outlook accounts.
transition
Partial. Not supported with Outlook accounts.

Samsung Mail against Gmail Android

They give the same answer on 126 of the 297 features both are tested on. Where they split:

Works in Samsung Mail, not in Gmail Android (142)

All 142

Works in Gmail Android, not in Samsung Mail (7)

<input type="text">not supported here
Buggy.
<textarea>not supported here
Buggy.
font-sizepartial here
Partial support.
anchor-linksnot supported here
Buggy.
fit-contentnot supported here
biminot supported here
amp4emailnot supported here

How Samsung Mail renders email

Samsung Mail is the default email app on Samsung Galaxy phones. It supports <style> blocks, media queries including prefers-color-scheme, @font-face, CSS animations, inline <svg> and <picture>. Its catch is the account: with an Outlook, Hotmail or Live address in the app, several of those stop working.

CSS animations: Supported, which makes Samsung Mail one of the few clients that runs @keyframes. Most others do not, so the static state still has to stand on its own.
Custom fonts (@font-face): Supported, except when the account is a Microsoft address (Outlook, Hotmail, Live). Readers on those accounts see the fallback stack.
top, left, right, bottom: Percentage values are not supported. position supports relative and absolute, not sticky or fixed.
<video>: Plays only with the controls attribute.
Anchor links: Tapping a link to an anchor in the email does nothing.

Media queries, including prefers-color-scheme, are supported, except when the account is a Hotmail or Outlook address, where they are not.

What works in Samsung Mail and breaks elsewhere

69 features work in Samsung Mail and in 6 or fewer of the other 20 clients, so they need a fallback.

All 67

Not listed: <base>, <body>, structural tags; the table below has them.

Where Samsung Mail is the outlier

1 feature work in at least 14 of the other 20 clients and is not supported here.

So an email that looks right in most clients can reach your reader in Samsung Mail without them.

white-space
Works in 15 of 21 · partial in 4 · not supported in 2
· not supported here

Paste your email and see what Samsung Mail does to it.

Check your email, free

No signup · Five clients free, Outlook Classic included · All 21 with an account

The checker needs a computer screen.

Dark mode in Samsung Mail

Works @media prefers-color-scheme works in Samsung Mail.

Works in 9 of 21.
Works color-scheme works in Samsung Mail.

Works in 4 of 21.
Not supported meta-color-scheme is not supported in Samsung Mail.

Works in 2 of 21.

Live preview: Samsung Mail supports @media (prefers-color-scheme: dark). Consider adding dark mode styles.

How to target Samsung Mail

Selectors that single out Samsung Mail, from the community list the engine ships (howtotarget.email). Copy one and replace .your-class-name.

css

3 lines

#MessageViewBody .your-class-name {
  /* Replace this comment with your styles */
}

No longer works (2)

css

3 lines

_:-webkit-full-screen, :root .your-class-name {
  /* Replace this comment with your styles */
}

css

5 lines

@media screen and (pointer) { 
  .your-class-name {
    /* Replace this comment with your styles */
  }
}

Build one for several clients →

Before you send to Samsung Mail

If your list has many Outlook.com or Hotmail addresses, check the email without web fonts, gradients and media queries: that is what those readers see in Samsung Mail.
Give every <video> the controls attribute.
Use pixel values for top, left, right and bottom.

Your next question

Gmail Android · Gmail iOS · Outlook iOS · Outlook Android · Apple Mail iOS · Yahoo Mail Android · Yahoo Mail iOS

Every feature in Samsung Mail

Show all 300

What breaks here (51) Everything (300) Untested (3)

HTML Elements · 5 of 48 not supported or partial here

<abbr> Works Works in 14 of 21
<acronym> Works Works in 13 of 21
<address> Works Works in 20 of 21
<audio> Works Works in 4 of 21
<base> Works Works in 4 of 21
<bdi> Works Works in 6 of 21
<blockquote> Works Works in 19 of 21
<body> Works Works in 5 of 21
<button type="reset"> Works Works in 10 of 21
<button type="submit"> Works Works in 11 of 21
<code> Works Works in 20 of 21
<del> Works Works in 20 of 21
<dfn> Works Works in 17 of 21
<dialog> Works Works in 5 of 21
<div> Works Works in 20 of 21
<form> Works Works in 10 of 21
<h1> Works Works in 20 of 21
<hr> Works Works in 18 of 21
<img> Works Works in 19 of 21
<input type="checkbox"> Works Works in 16 of 21
<input type="hidden"> Works Works in 16 of 21
<input type="radio"> Works Works in 16 of 21
<input type="reset"> Works Works in 15 of 21
<input type="submit"> Works Works in 12 of 21
<input type="text"> Buggy. Not supported Works in 13 of 21
<link> fix Not supported Works in 3 of 21
<marquee> Works Works in 8 of 21
<meter> Works Works in 11 of 21
<object> Partial support. Partial Works in 1 of 21
<p> Works Works in 20 of 21
<picture> Works Works in 4 of 21
<pre> Works Works in 20 of 21
<progress> Works Works in 6 of 21
<rp> Works Works in 15 of 21
<rt> Works Works in 15 of 21
<ruby> Works Works in 15 of 21
<select> Works Works in 14 of 21
<small> Works Works in 20 of 21
<span> Works Works in 20 of 21
<strike> Works Works in 17 of 21
<strong> Works Works in 20 of 21
<style> Works Works in 16 of 21
<svg> Works Works in 5 of 21
<table> Works Works in 20 of 21
<textarea> Buggy. Not supported Works in 13 of 21
<ul> Works Works in 7 of 21
<video> Partial support. Partial Works in 3 of 21
<wbr> Works Works in 16 of 21

HTML Attributes · 3 of 22 not supported or partial here

[align] Works Works in 17 of 21
[aria-describedby] Works Works in 9 of 21
[aria-hidden] Works Works in 13 of 21
[aria-label] Works Works in 13 of 21
[aria-labelledby] Works Works in 7 of 21
[aria-live] Works Works in 8 of 21
[background] Works Works in 16 of 21
[cellpadding] Works Works in 18 of 21
[cellspacing] Works Works in 18 of 21
[command] Partial. Partial Works in 3 of 21
[dir] Works Works in 19 of 21
[height] Works Works in 18 of 21
[hidden] Works Works in 5 of 21
[lang] Works Works in 15 of 21
[loading] Works Works in 4 of 21
[popover] Partial. Partial Works in 3 of 21
[required] Works Works in 7 of 21
[role] Works Works in 14 of 21
[srcset] Works Works in 4 of 21
[target] The attribute is supported but links always open in a new window anyway. Partial Works in 0 of 21
[valign] Works Works in 20 of 21
[width] Works Works in 18 of 21

HTML & Email Structure · 4 of 8 not supported or partial here

amp4email Not supported Works in 6 of 21
anchor-links Buggy. Not supported Works in 12 of 21
doctype Not supported Works in 13 of 21
html-comments Works Works in 18 of 21
html5-semantics Works Works in 6 of 21
image-maps Works Works in 15 of 21
mailto-links Works Works in 17 of 21
meta-color-scheme Not supported Works in 2 of 21

CSS At-Rules · 2 of 10 not supported or partial here

@font-face Works Works in 6 of 21
@import Not supported Works in 4 of 21
@keyframes Works Works in 7 of 21
@media Partial. Partial Works in 5 of 21
@media device-pixel-ratio Works Works in 10 of 21
@media hover Works Works in 9 of 21
@media orientation Works Works in 11 of 21
@media prefers-color-scheme Works Works in 9 of 21
@media prefers-reduced-motion Works Works in 9 of 21
@supports Works Works in 9 of 21

Pseudo-Elements · 0 of 6 not supported or partial here

::after Works Works in 6 of 21
::before Works Works in 6 of 21
::first-letter Works Works in 10 of 21
::first-line Works Works in 10 of 21
::marker Works Works in 10 of 21
::placeholder Works Works in 9 of 21

Pseudo-Classes & Selectors · 2 of 34 not supported or partial here

:adjacent-sibling Works Works in 16 of 21
:attribute-selector Works Works in 6 of 21
:chaining Works Works in 14 of 21
:checked Works Works in 9 of 21
:child-combinator Works Works in 16 of 21
:class-selector Works Works in 17 of 21
:descendant-combinator Works Works in 17 of 21
:first-child Works Works in 12 of 21
:first-of-type Works Works in 12 of 21
:focus Works Works in 10 of 21
:focus-visible Works Works in 6 of 21
:focus-within Works Works in 6 of 21
:general-sibling Works Works in 16 of 21
:grouping Works Works in 17 of 21
:has Works Works in 5 of 21
:hover Works Works in 12 of 21
:id-selector Works Works in 17 of 21
:lang Works Works in 6 of 21
:last-child Works Works in 12 of 21
:last-of-type Works Works in 12 of 21
:link Works Works in 13 of 21
:not Works Works in 6 of 21
:nth-child Works Works in 6 of 21
:nth-last-child Works Works in 6 of 21
:nth-of-type Works Works in 6 of 21
:only-child Works Works in 12 of 21
:only-of-type Works Works in 12 of 21
:target Works Works in 7 of 21
:type-selector Works Works in 17 of 21
:universal-selector Works Works in 16 of 21
:visited Not supported Works in 8 of 21
pseudo-class-active Not supported Works in 8 of 21
pseudo-class-default Untested Works in 10 of 21
pseudo-class-nth-last-of-type Works Works in 6 of 21

CSS Functions · 6 of 8 not supported or partial here

calc Works Works in 8 of 21
clamp Partial. Partial Works in 6 of 21
conic-gradient Partial. Partial Works in 6 of 21
fit-content Not supported Works in 11 of 21
linear-gradient Partial. Partial Works in 9 of 21
max Partial. Partial Works in 6 of 21
min Partial. Partial Works in 6 of 21
radial-gradient Works Works in 10 of 21

CSS Properties · 29 of 164 not supported or partial here

!important Works Works in 11 of 21
accent-color Works Works in 5 of 21
align-items Works Works in 13 of 21
animation Works Works in 5 of 21
aspect-ratio Not supported Works in 5 of 21
backdrop-filter Works Works in 6 of 21
background Works Works in 16 of 21
background-blend-mode Works Works in 13 of 21
background-clip Works Works in 14 of 21
background-color Works Works in 21 of 21
background-image Works Works in 16 of 21
background-origin Works Works in 14 of 21
background-position Works Works in 20 of 21
background-repeat Works Works in 20 of 21
background-size Works Works in 17 of 21
bimi Not supported Works in 9 of 21
block-size Works Works in 7 of 21
border Works Works in 20 of 21
border-collapse Works Works in 19 of 21
border-image Works Works in 7 of 21
border-inline Not supported Works in 3 of 21
border-inline-individual Partial. Partial Works in 3 of 21
border-inline-longhand Works Works in 4 of 21
border-radius Works Works in 16 of 21
border-radius-logical Not supported Works in 3 of 21
border-spacing Works Works in 17 of 21
bottom Partial. Partial Works in 11 of 21
box-shadow Works Works in 14 of 21
box-sizing Works Works in 16 of 21
caption-side Works Works in 20 of 21
clear Works Works in 9 of 21
clip-path Works Works in 8 of 21
color Works Works in 21 of 21
color-scheme Works Works in 4 of 21
column-count Works Works in 16 of 21
columns Works Works in 16 of 21
css-comments Works Works in 14 of 21
cursor Untested Works in 2 of 21
custom-properties Works Works in 6 of 21
direction Works Works in 21 of 21
display Works Works in 13 of 21
display:flex Works Works in 18 of 21
display:grid Works Works in 18 of 21
display:none Works Works in 20 of 21
empty-cells Works Works in 14 of 21
filter Works Works in 7 of 21
flex Works Works in 13 of 21
flex-basis Works Works in 13 of 21
flex-direction Works Works in 12 of 21
flex-wrap Works Works in 13 of 21
float Works Works in 14 of 21
font Works Works in 20 of 21
font-family Works Works in 21 of 21
font-kerning Works Works in 13 of 21
font-size Partial support. Partial Works in 13 of 21
font-size-adjust Untested Works in 10 of 21
font-stretch Not supported Works in 10 of 21
font-weight Works Works in 16 of 21
gap Works Works in 7 of 21
grid-template-columns Works Works in 7 of 21
height Works Works in 16 of 21
hyphenate-character Works Works in 4 of 21
hyphenate-limit-chars Not supported Works in 1 of 21
hyphens Works Works in 4 of 21
inert Works Works in 3 of 21
inline-size Works Works in 4 of 21
inset Not supported Works in 3 of 21
justify-content Works Works in 13 of 21
left Partial. Partial Works in 11 of 21
letter-spacing Works Works in 20 of 21
light-dark Partial. Partial Works in 3 of 21
line-height Works Works in 20 of 21
list-style Works Works in 11 of 21
list-style-image Works Works in 6 of 21
list-style-position Works Works in 19 of 21
list-style-type Works Works in 21 of 21
margin Works Works in 8 of 21
margin-block-start-end Works Works in 4 of 21
margin-inline-block Not supported Works in 6 of 21
margin-inline-start-end Works Works in 4 of 21
mask-image Works Works in 4 of 21
max-block-size Works Works in 5 of 21
max-height Works Works in 20 of 21
max-inline-size Works Works in 4 of 21
max-width Works Works in 20 of 21
min-block-size Works Works in 4 of 21
min-height Works Works in 19 of 21
min-inline-size Works Works in 5 of 21
min-width Works Works in 20 of 21
mix-blend-mode Works Works in 13 of 21
modern-color Not supported Works in 4 of 21
nesting Partial. Partial Works in 2 of 21
object-fit Works Works in 14 of 21
object-position Works Works in 14 of 21
opacity Works Works in 19 of 21
orphans Works Works in 10 of 21
outline Works Works in 20 of 21
outline-offset Works Works in 7 of 21
overflow Partial. Partial Works in 4 of 21
overflow-wrap Works Works in 2 of 21
padding Works Works in 20 of 21
padding-block-start-end Works Works in 4 of 21
padding-inline-block Not supported Works in 3 of 21
padding-inline-start-end Works Works in 4 of 21
position Partial. Partial Works in 2 of 21
resize Works Works in 1 of 21
rgb Works Works in 12 of 21
rgba Works Works in 12 of 21
right Partial. Partial Works in 11 of 21
scroll-snap Works Works in 6 of 21
shape-margin Works Works in 6 of 21
shape-outside Works Works in 6 of 21
system-ui Partial. Partial Works in 12 of 21
tab-size Works Works in 8 of 21
table-layout Works Works in 16 of 21
text-align Partial. Partial Works in 13 of 21
text-align-last Works Works in 7 of 21
text-decoration Works Works in 14 of 21
text-decoration-color Works Works in 17 of 21
text-decoration-line Works Works in 16 of 21
text-decoration-skip-ink Works Works in 7 of 21
text-decoration-style Works Works in 16 of 21
text-decoration-thickness Works Works in 7 of 21
text-emphasis Not supported Works in 9 of 21
text-emphasis-position Not supported Works in 4 of 21
text-indent Works Works in 13 of 21
text-justify Buggy. Not supported Works in 0 of 21
text-orientation Works Works in 13 of 21
text-overflow Not supported Works in 13 of 21
text-shadow Works Works in 12 of 21
text-transform Works Works in 20 of 21
text-underline-offset Works Works in 7 of 21
text-underline-position Works Works in 8 of 21
text-wrap Works Works in 4 of 21
top Partial. Partial Works in 11 of 21
transform Works Works in 7 of 21
transition Partial. Partial Works in 4 of 21
unit-ch Works Works in 15 of 21
unit-cm Works Works in 20 of 21
unit-em Works Works in 20 of 21
unit-ex Works Works in 20 of 21
unit-in Works Works in 20 of 21
unit-initial Works Works in 12 of 21
unit-mm Works Works in 20 of 21
unit-pc Works Works in 20 of 21
unit-percent Works Works in 20 of 21
unit-pt Works Works in 20 of 21
unit-px Works Works in 20 of 21
unit-rem Works Works in 15 of 21
unit-vh Works Works in 17 of 21
unit-vmax Works Works in 15 of 21
unit-vmin Works Works in 15 of 21
unit-vw Works Works in 18 of 21
user-select Works Works in 3 of 21
vertical-align Works Works in 21 of 21
visibility Works Works in 13 of 21
white-space Not supported Works in 15 of 21
white-space-collapse Works Works in 4 of 21
widows Works Works in 10 of 21
width Works Works in 20 of 21
word-break Buggy. Partial Works in 4 of 21
word-spacing Works Works in 14 of 21
writing-mode Works Works in 13 of 21
z-index Works Works in 17 of 21