Status

This page documents the implementation status of various HTML and CSS features in Blitz.

CSS PropertiesHTML ElementsEventsWPT Tests

CSS Properties are grouped into logical feature grouping, and within each group they are roughly ordered by the percentage of web pages that use that property. You can generally assume that if the longhand versions of a property are supported then the shorthand version will also be supported and vice-versa.

Core

% usePropertyStatus
92%display
display:inline✅ Supported
display:block✅ Supported
display:inline-block✅ Supported
display:flex✅ Supported
display:grid✅ Supported

Subgrid is not supported

display:table⚠️ Partial support taffy#467

Table layout is emulated with CSS Grid.

display:grid-lanes❌ Not supported taffy#910
display:none✅ Supported
display:contents✅ Supported
91%position
position:static❌ Not supported
position:relative✅ Supported
position:absolute✅ Supported
position:fixed❌ Not supported
position:sticky❌ Not supported

Note that because 'position:static' is not supported, 'position:absolute' nodes are always positioned relative to their immediate parent

87%overflow
overflow:visible✅ Supported
overflow:clip✅ Supported
overflow:hidden✅ Supported
overflow:scroll✅ Supported
overflow:auto❌ Not supported
85%box-sizing✅ Supported
85%z-index✅ Supported
84%cursor
keyword✅ Supported
custom image❌ Not supported
81%content (::before / ::after)
string✅ Supported
image❌ Not supported
gradient❌ Not supported
counter❌ Not supported
73%float✅ Supported
61%clear✅ Supported
41%order✅ Supported
27%zoom❌ Not supported

Visibility, Clipping & Isolation

% usePropertyStatus
86%opacity✅ Supported

Nodes with opacity are currently clipped regardless of the overflow style

75%visibility✅ Supported
51%clip-path❌ Not supported blitz#211
24%mask❌ Not supported
20%contain❌ Not supported
15%isolation❌ Not supported
6%content-visibility❌ Not supported

Sizing & Positioning

Flow relative versions of properties (e.g. max-inline-size) are also supported

% usePropertyStatus
92%width / height✅ Supported
80%min-width / min-height✅ Supported
83%max-width / max-height✅ Supported
89%inset✅ Supported
63%gap✅ Supported
35%aspect-ratio✅ Supported
54%object-fit✅ Supported
19%object-position✅ Supported

Padding, Margin & Borders

Flow relative versions of properties (e.g. padding-inline-start) are also supported

% usePropertyStatus
91%padding✅ Supported
91%margin✅ Supported
86%border-radius✅ Supported
76%border-color✅ Supported
64%border-width✅ Supported
61%border-style❌ Not supported
6%border-image❌ Not supported

Text Direction

% usePropertyStatus
45%direction⚠️ Partial support

Supported for block-level but not inline-level boxes. Auto-detection of RTL text is support for inline content.

12%all✅ Supported
13%unicode-bidi❌ Not supported
8%writing-mode❌ Not supported

Font

% usePropertyStatus
70%@font-face✅ Supported

It is not yet possible to override the family name or other matching criteria.

89%font-size✅ Supported
88%font-family✅ Supported
87%font-weight✅ Supported
78%font-style✅ Supported
52%font-display❌ Not supported
29%font-variant❌ Not supported
27%font-stretch✅ Supported
29%font-feature-settings❌ Not supported blitz#184
20%font-variation-settings✅ Supported
6%font-variant-ligatures❌ Not supported

Text

% usePropertyStatus
90%color✅ Supported
87%text-align✅ Supported
85%line-height✅ Supported
83%text-decoration✅ Supported
81%vertical-align❌ Not supported parley#291
81%white-space-collapse⚠️ Partial support
81%text-wrap-mode✅ Supported
72%text-transform
uppercase✅ Supported
lowercase✅ Supported
capitalize❌ Not supported
67%letter-spacing✅ Supported
66%text-overflow❌ Not supported parley#304
56%word-break✅ Supported
44%webkit-line-clamp❌ Not supported
39%overflow-wrap / word-wrap✅ Supported
34%text-indent✅ Supported
22%text-wrap-style❌ Not supported
22%text-decoration-line❌ Not supported
16%text-decoration-color✅ Supported
17%text-underline-offset❌ Not supported
11%word-spacing✅ Supported
12%tab-size❌ Not supported
13%text-decoration-thickness❌ Not supported
10%hyphens❌ Not supported
11%webkit-text-fill-color❌ Not supported
9%quotes❌ Not supported

Backgrounds

% usePropertyStatus
89%background-color✅ Supported
77%background-image✅ Supported
75%background-position✅ Supported
73%background-size✅ Supported
72%background-repeat✅ Supported
43%background-clip✅ Supported
8%background-origin✅ Supported
8%background-attachment❌ Not supported

Flexbox

% usePropertyStatus
75%flex-direction✅ Supported
70%flex-wrap✅ Supported
59%flex-grow✅ Supported
61%flex-shrink✅ Supported
41%flex-basis✅ Supported
0%webkit-box-*❌ Not supported

These properties are for the legacy flexbox model that was never widely adopted. Blitz does not ever intend to support these.

Grid

% usePropertyStatus
46%grid-template-{rows,columns}
px / percentage / fr✅ Supported
min-content / max-content / auto✅ Supported
fit-content()✅ Supported
named lines✅ Supported
subgrid❌ Not supported taffy#468
25%grid-{row,column}✅ Supported
23%grid-area✅ Supported
17%grid-template-areas✅ Supported
14%grid-auto-flow✅ Supported
11%grid-auto-{rows,columns}✅ Supported

Box Alignment

% usePropertyStatus
80%{align,justify}-content✅ Supported
80%{align,justify}-items✅ Supported
52%{align,justify}-self✅ Supported

2D Transforms

2D transforms are currently applied visually, but hit detection doesn't yet work properly for transformed nodes

% usePropertyStatus
84%transform⚠️ Partial support
55%transform-origin⚠️ Partial support
15%scale⚠️ Partial support
9%rotate⚠️ Partial support
9%translate⚠️ Partial support
5%transform-box❌ Not supported

3D Transforms

3D transforms are not currently supported

% usePropertyStatus
84%transform❌ Not supported
55%transform-origin❌ Not supported
15%scale❌ Not supported
9%rotate❌ Not supported
9%translate❌ Not supported
21%backface-visibility❌ Not supported
14%transform-style❌ Not supported
10%perspective❌ Not supported
5%transform-box❌ Not supported

Transitions & Animations

% usePropertyStatus
80%Transitions✅ Supported
70%Animations✅ Supported

Composition & Effects

% usePropertyStatus
82%box-shadow✅ Supported
44%outline✅ Supported
50%filter❌ Not supported
44%text-shadow❌ Not supported
32%backdrop-filter❌ Not supported
12%mix-blend-mode❌ Not supported
4%background-blend-mode❌ Not supported

Lists

% usePropertyStatus
46%list-style-type✅ Supported
12%list-style-position✅ Supported
10%counter-increment✅ Supported
9%counter-reset✅ Supported

Tables

% usePropertyStatus
45%border-collapse⚠️ Partial support

It is currently assumed that borders in tables with collapsed borders are uniform (have the same width/style/color). The border styles from the first cell are used.

31%border-spacing✅ Supported
18%table-layout✅ Supported
7%caption-side❌ Not supported

SVG

Rendering SVGs (including inline SVGs) is supported, but styling SVGs is not yet supported.

% usePropertyStatus
64%fill❌ Not supported
40%stroke❌ Not supported
43%stroke-width❌ Not supported
28%stroke-dashoffset❌ Not supported
26%stroke-dasharray❌ Not supported
14%fill-opacity❌ Not supported
12%stroke-linecap❌ Not supported
8%stroke-miterlimit❌ Not supported
6%stroke-opacity❌ Not supported

Interaction & Pointer events

% usePropertyStatus
70%pointer-events❌ Not supported
66%user-select❌ Not supported
42%touch-action❌ Not supported
14%caret-color✅ Supported
6%webkit-user-drag❌ Not supported
0%webkit-tap-highlight-color❌ Not supported

User Agent Hints

% usePropertyStatus
62%webkit-font-smoothing❌ Not supported
47%appearance❌ Not supported
39%will-change❌ Not supported
33%text-rendering❌ Not supported
22%text-size-adjust❌ Not supported
19%forced-color-adjust❌ Not supported
17%color-scheme❌ Not supported
15%scrollbar-color❌ Not supported
8%overflow-anchor❌ Not supported
7%image-rendering❌ Not supported

Miscellaneous / Other

% usePropertyStatus
40%scrollbar-width❌ Not supported
34%resize❌ Not supported
10%speak❌ Not supported
8%container❌ Not supported

Scroll Behaviour

% usePropertyStatus
18%scroll-behavior❌ Not supported
16%scroll-snap-type❌ Not supported
13%scroll-snap-align❌ Not supported
6%scroll-padding❌ Not supported
0%scroll-boundary-behavior❌ Not supported
0%scroll-boundary-behavior-y❌ Not supported

Multi-column Layout

% usePropertyStatus
6%column-count❌ Not supported

@page

% usePropertyStatus
6%size❌ Not supported
5%page-break-inside❌ Not supported