1. Introduction
Tests
This section is not normative, it does not need tests.
This section is non-normative.
This CSS module introduces properties to influence the visual styling of scrollbars, including their color (scrollbar-color) and thickness (scrollbar-width).
1.1. Scope
Tests
This section is not normative, it does not need tests.
The CSS Scrollbars Module is specifically for styling scrollbar controls themselves, e.g. their color & width in Level 1, and not their layout nor whether any content is scrollable. All layout impacts and content scrollability are specified in the CSS Overflow Module.
Based on documented use-cases, there are three main use-cases around scrollbars this module intends to resolve:
- Coloring scrollbars to fit better into the UI of a web application.
- Using a thinner scrollbar when the scrolling area is small.
- Hiding UA-provided scrollbars, to allow the provision of custom interfaces for scrolling without affecting other aspects of scrollability.
Tests
Tests that related to the specification as a whole, without exerting any specific part
1.1.1. Out Of Scope
Tests
This section is not normative, it does not need tests.
The internal structure, layout, and configuration of scrollbars, as well as precise control over their coloring, is out of scope. This is because different platforms have different scrollbar structures and styling conventions, and operating systems continuously evolve their scrollbar designs to provide better user experience. Pseudo-elements for selecting specific parts of a scrollbar, for example, were considered and rejected. While this level of fine control would be tempting for authors, the arrangement of the various parts—?or whether they’re even all present—?cannot be depended on. Providing too much control would allow authors to get perfect results on some platforms, but at the expense of broken results on others.
Note: Exposing the scrollbar-related ::-webkit- prefixed pseudo-elements to the Web
is considered a mistake by both the CSS Working Group and Webkit.
Nevertheless, see §?2.1 Interaction with non-standard features and §?3.1 Interaction with non-standard features.
1.2. Value Definitions
Tests
This section does not introduce any new normative requirement, it does not need tests.
This specification follows the CSS property definition conventions from [CSS2] using the value definition syntax from [CSS-VALUES-3]. Value types not defined in this specification are defined in CSS Values & Units [CSS-VALUES-3]. Combination with other CSS modules may expand the definitions of these value types.
In addition to the property-specific values listed in their definitions, all properties defined in this specification also accept the CSS-wide keywords as their property value. For readability they have not been repeated explicitly.
2. Scrollbar Colors: the scrollbar-color property
Tests
This section has partial test coverage.
Missing:
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Tests checking that the property does anything
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Tests checking that the colors apply to the right parts
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Initial value
The following tests have no basis in the spec: they assume that making the thumb and the track transparent must make the whole scollbar invisible. This is not necessarily true:
-
the scrollbar may have other parts, such as scroll up/down/left/right buttons
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the spec does not require that the thumb / track are painted solid with the specified colors
| Name: | scrollbar-color |
|---|---|
| Value: | auto | <color>{2} |
| Initial: | auto |
| Applies to: | scroll containers |
| Inherited: | yes |
| Percentages: | n/a |
| Computed value: | specified keyword or two computed colors |
| Canonical order: | per grammar |
| Animation type: | by computed value |
Tests
This property allows the author to set colors of an element’s scrollbars.
Tests
This test useful but insufficient: it checks what the property doesn't do, not what it does.
This test useful but insufficient: it checks that *if* the property works, current-color works.
These tests are useful but insufficient: *if* the property works at all, they check that it updates correctly.
- scrollbar-color-dynamic-1.html (live test) (source)
- scrollbar-color-dynamic-2.html (live test) (source)
- scrollbar-color-dynamic-3.html (live test) (source)
- scrollbar-color-dynamic-4.html (live test) (source)
- scrollbar-color-dynamic-5.html (live test) (source)
- scrollbar-color-dynamic-6.html (live test) (source)
- scrollbar-color-dynamic-7.html (live test) (source)
UAs must apply the scrollbar-color value set on the root element to the viewport.
Tests
The following test about viewport propagation is useful but insufficient; the test will pass if the property has no effect at all. Also missing:
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tests that check the interaction with css-contain, and in particular that that disables propagation
Note: Unlike overflow (and overflow-*) properties, scrollbar-color value set on the HTML body element are not propagated to the viewport.
- auto
-
The user agent determines the colors of the scrollbar.
It should follow platform conventions,
but may adjust the colors in accordance with color-scheme
or other contextual information
to better suit the page.
Tests
These tests check that that if the scrollbar adjusts based on the color scheme, then dynamic updates to the color scheme do cause an update of the scrollbar's colors.
- scrollbar-color-scheme-dynamic-1.html (live test) (source)
- scrollbar-color-scheme-dynamic-2.html (live test) (source)
- scrollbar-color-scheme-dynamic-3.html (live test) (source)
- scrollbar-color-scheme-dynamic-4.html (live test) (source)
- <color>
- The user agent should use the specified colors to adjust the rendering of the element’s scollbars, if any, applying the first color to the thumb of the scrollbar, and the second color to the track of the scrollbar.
The track refers to the background of the scrollbar, which is generally fixed regardless of the scrolling position.
The thumb refers to the moving part of the scrollbar, which usually floats on top of the track.
Some scrollbars also include additional controls, refered to as buttons, which usually sit at the top or bottom of the scrollbar on top of the track. This specification does not define whether and how buttons—?if present—?are colored.
If this property computes to a value other than auto, implementations may render a simpler scrollbar than the default platform UI rendering, and color it accordingly.
Note: Sometimes the UA is unable to customize the colors of native scrollbars, perhaps due to how they’re structured, or to a lack of control given by the native toolkit. The provision above allows the UA to replace them with differently-constructed scrollbars, which it does know how to color.
Note: User Agents are expected to use the color in the rendering of the scrollbar, but that does not imply they need to paint the entire thumb or track with a single solid featureless color. The specified color can be used as a tint for part of the component, lighter or darker shades of the color can be used for highlights, shadows, texture…
scrollbar-color : #8eb0dc #d2d4d6; This specific design is not only that single shade of blue over that single shade of gray: the thumb has a subtle vertical gradient going from a lighter shade at the top to a slightly darker shade at the bottom, darker notches in the middle, as well as a darker outline, all derived from the specified shade of blue; the light gray track has a darker outline. This design also happens to include buttons.
Nevertheless, authors cannot assume that this will necessarily be the case, as on a different platform or a different user agent the rendering could be a solid color thumb over a solid color track, as seen below.
Implementations may ignore any of the colors if the corresponding part do not exist on the underlying platform.
When using scrollbar-color property with specific color values, authors should ensure the specified colors have enough contrast between them. For the auto value, UAs should ensure the colors they use have enough contrast. See WCAG 2.1 SC 1.4.11 Non-text Contrast [WCAG21]. UAs may ignore these contrast requirements based on explicit user preferences (for example, when users choose a configuration option/setting that always ensures a particular scrollbar color / use of system default scrollbars).
Note: Implementations can take advantage of the fact that they have full discretion in how to apply the specified colors in order to visually respond to user interactions with the scrollbar (e.g. hovering or activating): they could alter which scrollbar parts the specified colors apply to, use darker or lighter shades of the specified colors, more or less saturated variants…
If the user agent displays the scrollbar without the track, they must ensure reasonable contrast between the thumb and what is behind it. However, if the author set the color of the track to be fully transparent, the user agent may assume that the author has provided for sufficient contrast even with an invisible track.
Note: This is typically relevant in the case of overlay scrollbars, either on platforms where the track is never displayed, or on platforms where it is only displayed when the scrollbar is being interacted with but not when scrolling with the mouse wheel or the track-pad. This does not apply in cases where the entire scrollbar is hidden as is often the case with overlay scrollbars while no scroll operation is ongoing and when the scrollbar is not being interacted with either.
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Doing nothing if it can determine that contrast is already sufficient
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Doing nothing if the design and geometry of the thumb ensures that some part of it will always be visible regardless of what is behind it
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Adding an outline, shadow, or glow around the thumb to provide contrast (possibly using the track color as the contrasting color, or possibly using a different shade of the thumb color)
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Adding some texture or geometry to the thumb so that it’s color isn’t uniform
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Drawing the track anyway in cases where not doing so yields insufficient contrast
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Replacing the thumb color with the track color when that provides better contrast
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Altering the luminosity of the specified thumb color while preserving its hue
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Disregarding the specified thumb color altogether and use automatically determined alternative
2.1. Interaction with non-standard features
On any element or pseudo-element where the computed value of scrollbar-color is anything other than the initial auto value, user agents must ignore any alternative non-standard means for authors to influence the rendering of scrollbars, such as the ::webkit-scrollbar family of pseudo-elements.
Tests
- scrollbar-color-001.html (live test) (source)
- scrollbar-color-002.html (live test) (source)
- scrollbar-color-003.html (live test) (source)
- scrollbar-color-004.html (live test) (source)
- scrollbar-color-005.html (live test) (source)
- scrollbar-color-006.html (live test) (source)
- scrollbar-color-007.html (live test) (source)
- scrollbar-color-008.html (live test) (source)
- scrollbar-color-009.html (live test) (source)
- scrollbar-color-010.html (live test) (source)
- scrollbar-color-dynamic-8.html (live test) (source)
3. Scrollbar Thickness: the scrollbar-width property
Tests
This section has partial test coverage.
Missing:
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Test that thin does something different from auto in at least some cases
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Test that none does not affect scrollability
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Initial value
| Name: | scrollbar-width |
|---|---|
| Value: | auto | thin | none |
| Initial: | auto |
| Applies to: | scroll containers |
| Inherited: | no |
| Percentages: | n/a |
| Computed value: | specified keyword |
| Canonical order: | per grammar |
| Animation type: | discrete |
Tests
This property allows the author to specify the desired thickness of an element’s scrollbars.
Tests
- scrollbar-width-paint-001.html (live test) (source)
- scrollbar-width-paint-002.html (live test) (source)
- scrollbar-width-paint-003.html (live test) (source)
- scrollbar-width-paint-004.html (live test) (source)
- scrollbar-width-paint-005.html (live test) (source)
- scrollbar-width-paint-006.html (live test) (source)
Scrollbars are a UI mechanism essential to interact with the page. Operating systems tend to want consistency in such controls to improve usability through familiarity, and users with specific preferences or needs can adjust the appearance of various UI components, including scrollbars, through OS or UA settings.
While using this property in support of specific UX goals is appropriate, authors should otherwise refrain from overriding such user preferences.
- auto
-
Implementations must use the default scrollbar width.
Note: On most systems, this corresponds to the traditional somewhat wide scrollbar. However, through OS or UA settings, users can have the ability to change what this default corresponds to, possibly making the default scrollbar wider or narrower than is typical.
- thin
-
Implementations should use thinner scrollbars than auto.
This may mean a thin variant of scrollbar provided by the platform,
or a custom scrollbar thinner than the default platform scrollbar.
The scrollbar must nonetheless remain wide enough to be usable.
(Implementers may wish to consult
WCAG 2.1 SC 2.5.5 Target Size. [WCAG21])
Tests
Note: User agents can use various strategies to ensure the usability of narrow scrollbars. For instance, in the case of overlay scrollbars, they can dynamically enlarge the scrollbar in response to a user attempting to interact with it. User agents on devices with touch screens can also adjust how they interpret finger taps to facilitate interacting with visually small touch targets.
User agents may disregard this value and treat it as auto, for instance when the user has indicated discomfort for thin scrollbars through some UA or OS setting. (User agents are encouraged to provide such a setting.)
Note: Some platforms only have a tiny scrollbar by default which cannot be reasonably made thinner. In such cases, this value will behave as auto.
- none
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Implementations must not display any scrollbar,
however the element’s scrollability by other means is not affected.
Tests
- textarea-scrollbar-width-none.html (live test) (source)
- scrollbar-width-keywords.html (live test) (source)
- scrollbar-width-001.html (live test) (source)
- scrollbar-width-002.html (live test) (source)
- scrollbar-width-003.html (live test) (source)
- scrollbar-width-004.html (live test) (source)
- scrollbar-width-007.html (live test) (source)
Using this value can prevent mouse-only users from being able to scroll. Authors should ensure that mouse-only users can still reach hidden content, even if they have no scrollwheel.Authors that use none should provide an alternative/equivalent visual hint that scrolling is possible and there is more content.Note: For situations where an element is to be scrolled only by programmatic means, and not by direct user manipulation, overflow: hidden is appropriate, not scrollbar-width: none.
* { scrollbar-width : auto !important; } This will ensure that all scrollbars are sized as per OS and UA settings regardless of author styles.
UAs must apply the scrollbar-width value set on the root element to the viewport.
Tests
Note: Unlike the overflow property (and its longhands),
a scrollbar-width value set on the HTML body element is not propagated to the viewport.
Note: This specification does not define the exact position or shape of the scrollbar, or any animation thereof, such as fading or sliding in/out of view.
3.1. Interaction with non-standard features
On any element or pseudo-element where the computed value of scrollbar-width is anything other than the initial auto value, user agents must ignore any alternative non-standard means for authors to influence the rendering of scrollbars, such as the ::webkit-scrollbar family of pseudo-elements.
Tests
- scrollbar-width-010.html (live test) (source)
- scrollbar-width-011.html (live test) (source)
- scrollbar-width-012.html (live test) (source)
- scrollbar-width-013.html (live test) (source)
- scrollbar-width-014.html (live test) (source)
- scrollbar-width-015.html (live test) (source)
- scrollbar-width-016.html (live test) (source)
Appendix A. Acknowledgments
Tests
This section is not normative, it does not need tests.
This appendix is non-normative.
The CSS Working Group and the Editors of this specification would like to express our gratitude to the following people, as this specification would not have been possible without their feedback and contributions: Chris Lilley, Emilio Cobos álvarez, Eric Shepherd, Eric Willigers, fantasai, Greg Whitworth, jonjohnjohnson, L. David Baron, Luke Warlow, Oriol Brufau, Patrick H. Lauke, Rene Haas, Rick Byers, Simon Fraser, Tab Atkins Jr., Xidorn Quan.
In particular, thanks for the use-cases, prototyping, implementation, and feedback from Tab Atkins and Xidorn Quan. Thanks for accessibility review and contributions (#3315) from Patrick H. Lauke.
Appendix B. Changes
Tests
This section is not normative, it does not need tests.
This appendix is non-normative.
Changes since the 9 December 2021 Candidate Recommendation
Tests
This section is not normative, it does not need tests.
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Switched the Animation type of scrollbar-width to discrete, reflecting the fact that this property only takes keyword values.
Changes since the 2025-08-08 Working Draft
Tests
This section is not normative, it does not need tests.
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Boilerplate changes for CR
Changes from the 2025-08-08 Working Draft
Tests
This section is not normative, it does not need tests.
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Switched "should" to a "must" with regards to accessibility of narrow scrollbars. (see Issue 6675)
Changes from the 2025-08-08 First Public Working Draft
Tests
This section is not normative, it does not need tests.
- #6538: removed light and dark values of scrollbar-color in favor of allowing the UA to tune auto in accordance with color-scheme or other contextual information.
- #3237: scrollbar-color computed value changed to: specified keyword or two computed colors
- #4693: Clarified scope: styling scrollbar controls themselves, no layout or scrollability.
- #3315: More and updated accessibility considerations for scrollbar-color and scrollbar-width.
Appendix C. Security and Privacy
Tests
This section is not normative, it does not need tests.
This appendix is non-normative.
Considerations for Security
Tests
This section is not normative, it does not need tests.
No specific concerns regarding security have been identified for this specification.
Considerations for Privacy
Tests
This section is not normative, it does not need tests.
No specific concerns regarding privacy have been identified for this specification.
Self-review questionnaire
Tests
This section is not normative, it does not need tests.
Per the Self-Review Questionnaire: Security and Privacy: Questions to Consider
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Does this specification deal with personally-identifiable information?
No.
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Does this specification deal with high-value data?
No.
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Does this specification introduce new state for an origin that persists across browsing sessions?
No.
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Does this specification expose persistent, cross-origin state to the web?
No.
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Does this specification expose any other data to an origin that it doesn’t currently have access to?
No.
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Does this specification enable new script execution/loading mechanisms?
No.
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Does this specification allow an origin access to a user’s location?
No.
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Does this specification allow an origin access to sensors on a user’s device?
No.
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Does this specification allow an origin access to aspects of a user’s local computing environment?
No.
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Does this specification allow an origin access to other devices?
No.
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Does this specification allow an origin some measure of control over a user agent’s native UI?
Yes. The scrollbar-* properties enable the page to change the color and width of the scrollbar of the user agent’s native UI, e.g. scrollbars on the page’s window, on framed content embedded in the page, or on overflowing elements with scrollbars in the page.
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Does this specification expose temporary identifiers to the web?
No.
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Does this specification distinguish between behavior in first-party and third-party contexts?
No.
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How should this specification work in the context of a user agent’s "incognito" mode?
No differently.
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Does this specification persist data to a user’s local device?
No.
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Does this specification have a "Security Considerations" and "Privacy Considerations" section?
Yes.
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Does this specification allow downgrading default security characteristics?
No.
Appendix D. Considerations for accessibility
Tests
This section is not normative, it does not need tests.
This appendix is non-normative.
Using this property in such cases is preferable to authors building a custom thin-looking scrollbar in via script or proprietary extensions, because it does give the user the opportunity to override it.
User style sheets do provide such an override, and additionally, user agents are encouraged to expose a setting letting users express that they do not want thin scrollbars to be used.
The CSS Working Group also acknowledges the needs of some users to have scrollbars that are wider than is typical. Operating systems and user agents can offer a means to let users express that preference, and in such cases, CSS will honor that choice.