Unlock Immediate Diagonal Scrolling with CSS scroll-axis-lock: none

~

Scroll Axis Locking?

By default, a browser often “locks” a user’s scrolling gesture to a single axis when that gesture starts with significantly more movement in one axis than in the perpendicular axis.

For example, say a user drags their finger on the screen such that the element underneath the finger would be scrolled by 500px in the y-axis and 3px in the x-axis. Because the gesture is almost entirely vertical, the browser might interpret the user’s intent to be a perfectly vertical scroll. As such, the browser can ignore the 3px scroll delta and (possibly) all further x-axis deltas for the remainder of the gesture. In this case, the browser has “locked” the scroll to the y-axis — a technique also known as “railing”.

In many cases, this scroll-locking behavior improves the user’s experience by avoiding accidental scrolls along the other axis when the user’s intent was to scroll only one axis.

However, in cases where you wish an element to always be diagonally scrollable, this locking behavior forces the user to start their gesture at an angle that doesn’t trigger the locking, often not in alignment with the author’s intended user experience.

Thankfully, a recent change to CSS now offers control over this, namely the scroll-axis-lock property described in the CSS Overflow 5 specification.

~

Control scroll axis-locking with scroll-axis-lock

The scroll-axis-lock property gives you control scroll axis-locking. The property accepts the following values:

• auto (default): The browser may lock the scroll to a single axis if it determines the gesture is predominantly 1-dimensional. The browser may allow you to break out of scroll axis lock as part of your current gesture, but the thresholds to do that are different per browser and platform.
• none: Disables the locking mechanism entirely. The scroll container will faithfully follow the user’s exact input, allowing for unrestricted diagonal panning.

.scroller {
  scroll-axis-lock: auto; /* Default */
  /* or */
  scroll-axis-lock: none;
}

In the following video, you can compare how both values behave. The recording show Chrome 153 on macOS, but with a different scroll-axis-lock value. The scroll is performed using a trackpad.

The difference also becomes very clear when doing scrolls that follow a circular motion:

~

Try it yourself

To feel the difference yourself (and to create the screenshots and videos above), I built a demo that samples your pointer’s X/Y input deltas and compares them against the actual scrollLeft and scrollTop output of the container.

If you try scrolling diagonally with scroll-axis-lock: auto, you’ll notice the status indicator flag can show a “Axis Locked” warning it detects that the browser is ignoring your perpendicular input. As mentioned before this totally depends on the browser and platform, so could be that you don’t see this warning at all.

If you set the toggle to scroll-axis-lock: none, and try again, scrolling straight is way more “jittery” and scrolling diagonally immediately pans in both directions simultaneously, exactly following your gesture.

~

# Browser Support

Support for scroll-axis-lock looks like this:

Chromium (Blink)

✅ Supported in Chromium 153

Firefox (Gecko)

❌ No Support

Safari (WebKit)

❌ No Support

~

Feature Detection

There is no real need to feature detect this, as you can safely use scroll-axis-lock today as a progressive enhancement. Since it doesn’t break anything when ignored, you can just declare it directly 🙂

If you really do need to feature detect it — perhaps to load some alternative code? — you can use an @supports rule in CSS or CSS.supports() in JS to check.

@supports (scroll-axis-lock: none) {
  /* Control over scroll-axis locking supported */
}

if (CSS.supports('scroll-axis-lock: none')) {
  /* Control over scroll-axis locking supported */
}

You can see it in action in the following demo:

See the Pen
CSS scroll-axis-lock Support test by Bramus (@bramus)
on CodePen.

~