AdSense side rail ads 2026 are desktop overlay advertisements that remain attached to the sides of a website while a visitor scrolls through the page. They can use the unused space beside the main content area without inserting another advertisement between article paragraphs.
Unlike anchor ads, which appear at the top or bottom of a screen, side rails appear on the left, right or both sides of a page. Google currently makes the format available on desktop and other suitable widescreen layouts through AdSense Auto Ads. 2
Side rail ads can provide additional desktop advertising opportunities. However, enabling the format does not guarantee that an advertisement will appear during every desktop page view or that earnings will increase.
The correct approach is to choose an appropriate position, protect important website sections, test the format and measure its effect on both revenue and usability.
What Are AdSense Side Rail Ads?
Side rail ads are part of the Overlay formats available in Google AdSense Auto Ads. They stick to the sides of a page and remain visible as the visitor scrolls.
Google groups the following formats under Auto Ads overlays:
- Anchor ads
- Vignette ads
- Side rail ads
Overlay formats are displayed over or beside the page without becoming a normal part of the article layout. Side rail ads are specifically intended for widescreen devices such as desktop computers. 3
A typical side rail experience works like this:
- A desktop visitor opens an eligible page.
- AdSense analyzes the page structure and existing advertising.
- The browser window provides sufficient widescreen space.
- An eligible side rail ad appears on one or both sides.
- The advertisement remains attached while the visitor scrolls.
- The main article remains in its normal content column.
Auto Ads analyze factors such as page layout, content and existing Google ads. Consequently, turning on side rails makes the format eligible but does not force an ad to appear on every page view. 4
AdSense Side Rail Ads vs Sidebar Ads
Side rail ads should not be confused with traditional sidebar advertisements.
| Feature | Side rail ads | Manual sidebar ads |
|---|---|---|
| Placement method | AdSense Auto Ads | Publisher-created ad unit |
| Location | Beside the page on widescreen devices | Inside the website’s sidebar |
| Behaviour | Remains attached while scrolling | Depends on the website’s CSS |
| Device support | Desktop or suitable widescreen layouts | Desktop and potentially mobile |
| Position control | Left, right, or both | Exact template position |
| Code required | Main AdSense Auto Ads code | Main code plus individual ad-unit code |
| Reporting | Side rail ad-format reporting | Individual ad-unit reporting |
| Maintenance | Managed from AdSense | Managed through the website template |
A manual sidebar unit occupies space inside your theme’s layout. A side rail ad normally uses space outside or beside the primary page container.
You can use side rail ads and manual ad units on the same website, but you should check whether the combined setup makes desktop pages look overcrowded.
Current Side Rail Position Settings in 2026
As of August 22, 2026, Google provides three position choices for AdSense side rail ads:
- Left and right
- Left only
- Right only
These controls were introduced on May 20, 2025 to give publishers more control over overlay-ad positions. They remain available under the advanced Overlay formats settings. 5
How to Enable AdSense Side Rail Ads
Follow these steps:
- Sign in to your Google AdSense account.
- Click Ads in the navigation menu.
- Locate your website in the sites table.
- Click the Edit icon next to the website.
- Wait for the ad-settings preview to load.
- Turn on Auto Ads under Ad settings.
- Open Overlay formats.
- Select Side rail ads.
- Expand Advanced settings.
- Select the side rail position.
- Review the desktop preview.
- Click Apply to site.
- Select Apply now or Run experiment first.
- Save the settings.
The main AdSense code should be installed on every eligible page. Google says Auto Ads changes can take up to one hour to appear. 2
Choosing the Best Side Rail Ad Position
There is no universal position that produces the best results for every website. Your selection should consider the site layout, available space and important floating elements.
1. Left and Right
This option allows side rail ads to appear on both sides of the page.
It may be suitable when:
- The main content container is centered.
- The desktop layout has substantial space on both sides.
- There are no floating share buttons or navigation controls.
- You want to maximize eligible side rail opportunities.
- Your articles are sufficiently valuable and detailed.
Potential problems include:
- A heavily commercial appearance
- Conflicts with floating tools
- Too many visible ads when manual units are also present
- Reduced visual focus on the article
Start with an experiment rather than applying both sides to all visitors immediately.
2. Left Only
This option limits side rail ads to the left side.
It may be suitable when:
- The right side contains a sticky sidebar.
- A live-chat button appears on the lower right.
- Important tools are positioned on the right.
- The left side has more available space.
- The theme uses a right-aligned content column.
Check whether your website uses a floating table of contents or social-sharing bar on the left before selecting this option.
3. Right Only
This option limits side rails to the right side.
It may be suitable when:
- The left side contains a floating table of contents.
- The theme has important left-side navigation.
- Your live-chat widget is not on the right.
- The page design looks more balanced with right-side advertising.
- You prefer a conservative one-rail setup.
For many websites, Right only or Left only is a cautious starting point because it introduces the format without placing advertising on both sides.
Recommended Starting Configuration
The following is a practical testing configuration, not a guaranteed revenue formula:
| Setting | Suggested starting point |
|---|---|
| Side rail ads | Enabled |
| Position | Right only |
| Auto Ads experiment | Recommended |
| Desktop preview | Check several page templates |
| Manual sticky sidebar ads | Review for conflicts |
| Important floating tools | Protect or reposition |
| Legal and utility pages | Consider page exclusions |
| Initial testing period | Two to four weeks |
| Major changes | One at a time |
If your website has a simple, centered layout with large empty margins, you can later test Left and right against the one-sided setup.
Why Side Rail Ads May Not Appear
Turning on side rail ads does not mean they will display during every page view.
Possible reasons include:
The Visitor Is Using Mobile
Google describes side rail ads as a desktop format for widescreen devices. Do not expect them to appear on normal mobile screens. 2
The Browser Window Is Too Narrow
A visitor may be using a desktop computer with a narrow browser window. Because side rail ads are designed for widescreen layouts, the format may not have a suitable placement opportunity.
Auto Ads Are Disabled
The Side rail ads option requires Auto Ads to be enabled for the website.
AdSense Code Is Missing
The main AdSense code should be present on the page. Check whether the code was accidentally removed from a new WordPress template or custom landing page.
The Page Has Been Excluded
An Auto Ads page exclusion overrides your general website settings and prevents Auto Ads from appearing on the selected URL. 6
The Settings Have Not Updated
Google says it may take up to one hour for Auto Ads changes to apply. Clear your website cache and CDN cache, and then test again after allowing enough time. 2
No Eligible Ad Is Available
Enabled Auto Ads formats are placed selectively. AdSense analyzes the page and available advertising opportunity rather than forcing every format to serve on every page view. 4
An Ad Blocker Is Active
Browser extensions, network-level filters and privacy tools can block AdSense advertising during your test.
How to Prevent Side Rail Ads From Overlapping a Section
Google provides an HTML attribute that can prevent side rail ads from appearing over a specific page section:
google-side-rail-overlap="false"Add the attribute to the HTML element containing the section you want to protect.
Example:
<div google-side-rail-overlap="false">
<h2>Important Application Information</h2>
<p>This section should not be overlapped by side rail ads.</p>
</div>Google states that all elements inside the selected container will be protected from side rail overlap. 2
Example for a Header
<header google-side-rail-overlap="false">
<nav>
<!-- Main navigation -->
</nav>
</header>Example for a Floating Table of Contents
<aside class="table-of-contents" google-side-rail-overlap="false">
<!-- Table of contents links -->
</aside>Example for a Footer
<footer google-side-rail-overlap="false">
<!-- Footer content -->
</footer>Example for an Important WordPress Section
<div class="important-download-section" google-side-rail-overlap="false">
<h2>Download Official Document</h2>
<a href="/document.pdf">Download PDF</a>
</div>Use this attribute only where necessary. Applying it to the entire page container may eliminate many potential side rail opportunities.
Before editing theme files, create a backup and test your changes on a staging website if possible.
Side Rail Overlap Attribute vs Excluded Areas
These controls have different purposes.
Side Rail Overlap Attribute
Use this code:
google-side-rail-overlap="false"when you want to protect a specific HTML section from side rail overlap.
Other Auto Ads can still appear on the page.
Excluded Areas
The Excluded areas control applies only to in-page Auto Ads. Google specifically states that excluded areas do not prevent overlay formats from appearing. Side rails are overlay ads, so creating an excluded area is not the correct way to manage them. 7
Page Exclusions
Use a page exclusion when you want to disable Auto Ads on:
- One exact URL
- An entire URL section
Page exclusions override the general Auto Ads configuration. They affect Auto Ads broadly rather than only side rail ads. URLs containing query parameters or fragments are not supported by the page-exclusion tool. 6
Pages You May Want to Exclude
Consider excluding Auto Ads from:
- Privacy Policy
- Terms and Conditions
- Contact forms
- Login pages
- Account dashboards
- Checkout pages
- Thank-you pages
- Very short pages
- Pages without substantial original content
- Important application pages
- Pages containing complex interactive tools
Do not automatically exclude every article. Use page exclusions only where advertising creates a genuine usability, policy or design problem.
How to Run a Side Rail Ads Experiment
Instead of immediately enabling side rails for every visitor, run an Auto Ads experiment.
You can test:
- Side rail ads on versus off
- Left and right versus right only
- Left and right versus left only
- One side rail position against your current settings
Follow these steps:
- Sign in to AdSense.
- Open Optimization.
- Click Experiments.
- Select Create new experiment.
- Choose Auto Ads.
- Select your website.
- Configure the side rail variation.
- Give the experiment a descriptive name.
- Decide whether Google should automatically choose the winner.
- Start the experiment.
Only one Auto Ads experiment can run on a website at a time, and you do not need to modify your AdSense code. Google recommends waiting until the test shows Result ready before selecting a winner. Depending on traffic, this may take several days or one or two months. 8
When an experiment is started directly from the Auto Ads setup flow, Google can apply the test to 50% of the site’s traffic for up to 90 days, finishing earlier when enough data is collected. 2
How to Track Side Rail Ad Performance
To create a side rail report:
- Open Reports in AdSense.
- Create a custom report.
- Click the filter option.
- Select Ad format.
- Choose Side rail ads.
- Apply the filter.
- Select the date range you want to compare.
Google documents the Ad format filter as the method for isolating side rail performance. 2
Monitor:
- Estimated earnings
- Ad impressions
- Ad RPM
- Desktop performance
- Visitor country
- Date and time trends
- Performance before and after activation
The Ad formats report can also help you compare automatically placed formats with standard manual ad units. Reporting data is currently limited to the previous three years. 9
You should also review website-experience metrics, including:
- Desktop engagement time
- Pages per session
- Returning visitors
- Exit rate
- Form completion
- Download clicks
- Affiliate conversions
- User complaints
- Page-loading performance
Do not keep a setting only because it generates additional impressions. Evaluate whether it creates meaningful incremental revenue without making the site harder to use.
10 Ways to Optimize AdSense Side Rail Ads
1. Start With One Side
Begin with Left only or Right only. Compare this setup with Left and right after collecting baseline data.
2. Check Every Desktop Template
Test:
- Homepage
- Articles
- Categories
- Author pages
- Search pages
- Long tutorials
- Short articles
- Legal pages
- Landing pages
One position may work well on articles but conflict with a homepage sidebar.
3. Review Floating Elements
Look for conflicts with:
- Social-sharing buttons
- Live-chat widgets
- Accessibility controls
- Back-to-top buttons
- Sticky tables of contents
- Cookie-consent notices
- Floating navigation menus
Use the side rail overlap attribute when a particular section requires protection.
4. Keep the Main Content Easy to Read
The format should not make the article appear squeezed, covered or visually secondary to advertisements.
Google Publisher Policies do not permit advertising implementations that severely interfere with content consumption or push content off the visible display. 10
5. Review Existing Manual Ads
A page with side rails, a sticky sidebar unit, multiple in-content ads and an anchor ad can become excessively commercial.
Google does not allow pages where advertising and other paid promotional material exceed publisher content. 11
6. Do Not Place Buttons Near Ads
Be careful with floating navigation, download buttons and other controls near advertising. Even an unintentional layout that causes accidental clicks can result in a policy notification. 12
7. Use a Responsive Content Width
Check that the article remains comfortably readable on common laptop and desktop resolutions.
A very wide content container may leave little room for a desktop side rail. This is a practical layout consideration rather than a guarantee that changing the width will make ads appear.
8. Test Logged-In and Logged-Out Views
WordPress administrators may see a different layout because of the admin toolbar, caching rules or disabled advertising.
Use a private browser window for a more realistic test.
9. Avoid Multiple Simultaneous Changes
Do not change side rail positions, banner density, vignette frequency and anchor settings on the same day.
Change one major setting at a time so that you can identify its effect.
10. Compare Incremental Revenue
Measure whether side rail revenue is additional or whether it changes the performance of your existing ad units.
Auto Ads experiment results measure the effect across the complete website, including manual ad units—not only the tested Auto Ads format. 8
AdSense Side Rail Policy and UX Checklist
Before applying the format to all desktop visitors, confirm that:
- Side rail ads do not cover the main article.
- Navigation remains visible and usable.
- Floating buttons do not overlap advertisements.
- Ads cannot be confused with website controls.
- Desktop forms remain accessible.
- The article remains readable at different resolutions.
- The website does not ask users to click ads.
- Paid promotional content does not exceed publisher content.
- Important sections use overlap protection when needed.
- Legal and utility pages have been reviewed.
- Existing manual advertising has been audited.
- Revenue is evaluated together with user engagement.
- The Policy Center has been checked.
Google prohibits encouraging accidental clicks and warns publishers to keep advertisements away from navigation buttons, download buttons, menus and other heavily used controls. 12
Common Side Rail Ads Problems
Side Rail Ads Are Enabled but Not Showing
Check:
- The device is a desktop.
- The browser window is sufficiently wide.
- Auto Ads are enabled.
- Side rails are selected.
- The AdSense code is present.
- The page is not excluded.
- An ad blocker is not active.
- At least one hour has passed since the change.
- The live page—not only the preview—has been tested.
Ads Appear on the Wrong Side
Open:
Ads → Edit site → Overlay formats → Advanced settings
Confirm whether you selected:
- Left and right
- Left only
- Right only
Apply and save the corrected setting. Allow up to one hour for the update. 3
A Side Rail Covers a Floating Element
Add the following attribute to the HTML container holding the affected element:
google-side-rail-overlap="false"If the issue affects the complete page and cannot be fixed safely, consider an Auto Ads page exclusion.
Side Rails Make the Website Look Crowded
Try:
- Changing from both sides to one side
- Removing a manual sticky-sidebar unit
- Disabling desktop anchor ads
- Reducing other promotional material
- Excluding short pages
- Running an experiment with side rails disabled
Side Rail Revenue Is Very Low
Low performance may result from limited desktop traffic, low advertiser demand, infrequent eligible placements or a small number of widescreen page views.
Do not redesign the entire website only to force the format. Compare the implementation with your existing ad formats and overall desktop performance.
30-Day Side Rail Testing Plan
Days 1–5: Record Your Baseline
- Record total AdSense earnings.
- Record desktop Page RPM.
- Review desktop traffic percentage.
- Check existing overlay formats.
- List all floating website elements.
- Review the Policy Center.
Days 6–10: Configure the Format
- Enable side rail ads.
- Start with Right only or Left only.
- Test common desktop resolutions.
- Protect important sections.
- Add necessary page exclusions.
- Clear website and CDN caches.
Days 11–25: Collect Data
- Monitor side rail impressions and earnings.
- Compare desktop engagement.
- Check pages per session.
- Review important button interactions.
- Record user complaints.
- Avoid making major theme or ad changes.
Days 26–30: Evaluate
- Compare revenue with the baseline.
- Review side rail Ad RPM.
- Check whether engagement declined.
- Test Left and right only if the one-sided setup is successful.
- Remove the format if it creates layout or policy problems.
- Retain it only when it produces measurable value.
Frequently Asked Questions
What are AdSense side rail ads?
They are Auto Ads that remain attached to the sides of a page while it is viewed and scrolled on a desktop or suitable widescreen device. 2
Do side rail ads appear on mobile?
No. Google currently describes side rail ads as a desktop format. Mobile visitors may see other eligible Auto Ads formats instead. 2
Can I choose the side rail position?
Yes. The current options are Left and right, Left only and Right only. 3
What is the best side rail position?
There is no universal best position. Start with one side, check your layout and then run an experiment against a two-sided configuration.
Can I use side rails with manual ad units?
Yes. Auto Ads can analyze existing Google ad units and operate alongside them. However, you should ensure that the combined advertising does not crowd the page. 4
How can I prevent overlap with an important section?
Add google-side-rail-overlap="false" to the HTML container holding that section. 2
Do excluded areas disable side rail ads?
No. Excluded areas apply to in-page Auto Ads. Side rail ads are an overlay format. Use the overlap attribute or a page exclusion instead. 7
Can I disable side rails on only one page?
You can add an Auto Ads page exclusion for that URL, but it will stop Auto Ads generally on the selected page—not only side rails. 6
How long do side rail settings take to update?
Google says Auto Ads changes can take up to one hour to appear. 2
How do I check side rail earnings?
Create a custom AdSense report and filter the Ad format to Side rail ads. 2
Do side rail ads guarantee higher earnings?
No. They provide an additional desktop advertising opportunity, but results depend on your traffic, layout, advertiser demand and visitor behaviour.
Conclusion
AdSense side rail ads can monetize unused desktop space by displaying advertisements on the left, right or both sides of a widescreen page.
Start with a one-sided configuration, test the website on common desktop resolutions and use google-side-rail-overlap="false" to protect important sections. Remember that regular Excluded areas do not control side rail ads because they apply only to in-page formats.
Do not evaluate side rails using impressions alone. Compare estimated earnings, desktop RPM, engagement, navigation quality and policy risk.
A controlled Auto Ads experiment is the safest method for determining whether Left only, Right only, both sides or no side rail ads provide the best overall result for your website.