Why do all my Webflow site pages have a horizontal overlay, even after trying to hide overflowing content and using elements with 100vh?

TL;DR

Inspect for overflowing elements using Webflow’s X-ray Mode or DevTools.
Apply overflow-x: hidden to <body> and <html> in Webflow and custom CSS.
Avoid 100vw width; use width: 100% or max-width: 100vw instead.
Check for negative margins or hidden side elements causing extra width.
Verify flexbox/grid settings to prevent unintended stretching.
Test on different screen sizes using Webflow’s responsive preview and larger breakpoints.
If the issue persists, remove elements one by one to isolate the problem.

A persistent horizontal overflow issue in Webflow usually happens due to elements exceeding the viewport width. Even if you’ve set overflow: hidden, certain elements or interactions may still cause this. Here’s how to troubleshoot and fix it.

1. Check for Overflowing Elements

Enable Webflow’s X-ray Mode: Press CMD + Shift + X (Mac) or CTRL + Shift + X (Windows) to quickly inspect any elements extending beyond the viewport.
Use Webflow’s Navigator Panel: Inspect each section, container, or grid to find elements with unexpected widths.
Manually Inspect via Browser Tools: Open Chrome DevTools (F12 or Right Click > Inspect), then look for any elements exceeding 100vw.

2. Set `overflow: hidden` on the `body` and `html`

Go to the Body (<body>) Element in Webflow.
Apply overflow: hidden via the Style Panel under “Layout.”
Repeat for the html element using custom CSS:
Add this in Webflow Page Settings > Custom Code > Inside <style> tags in the <head> section:
```css
html, body {
overflow-x: hidden;
}
```
Note: If you have animations relying on horizontal movement, test thoroughly, as hidden overflow may prevent scroll-based effects.

3. Ensure No Elements Use Fixed `100vw` Width

Some elements use 100vw, but this doesn’t account for vertical scrollbars, causing slight horizontal overflow.
Instead, use:
width: 100% (prevents extending beyond the body).
max-width: 100vw (ensures limits on extra-wide elements).
Check components like sliders, animations, or large images, which often create unwanted extra width.

4. Look for Negative Margins or Hidden Side Elements

Check if any elements use negative margins (margin-left: -Xpx), which might push sections off-screen.
Hidden elements (like an off-screen side menu) may unintentionally cause overflow.
If you have a hidden menu, ensure it’s wrapped in a div with overflow: hidden.

5. Verify Grid and Flexbox Settings

Grid: Adjust “Min/Max” values for columns to prevent extending beyond the viewport.
Flexbox: Avoid min-width: auto on child elements, which may cause unexpected extra width.

6. Test on Different Devices & Screen Sizes

Resize your browser to smaller sizes and enable Webflow’s responsive design preview (Device Icons at the top of the Webflow Designer).
Expand the largest breakpoint (e.g., 1920px+) in Webflow, as overflow often occurs here.