Google is running another round of interface tests on Sitelinks, this time changing how the feature renders inside mobile search results for text-based ads. Search consultant Brodie Clark spotted the variation and posted screenshots on X, with the initial sighting also flagged by SERPalerts on September 27, 2026.

The new design stacks Sitelinks vertically, listing them line by line rather than in the row format advertisers and searchers are accustomed to. A horizontal line runs across the left side of the snippet, creating a margin that visually separates the Sitelinks block from the rest of the ad. Clark described the test plainly: "Google is testing out a new mobile sitelink display for text-based ads, featuring all sitelinks in darker text and a margin on the left-hand side."

The darker text treatment is the other notable change. In the standard layout, Sitelinks typically render in a lighter or more muted style compared to primary ad copy. Pulling them into darker text gives the links greater visual weight, which could increase their share of clicks within an ad unit — although Google has not confirmed the test, its purpose, or any planned rollout, and any click-behavior impact remains speculation until Google comments.

This is a tool-signal sighting, not a confirmed product change. It comes from independent SERP monitoring by Clark and SERPalerts, not from a Google announcement. Google routinely runs interface experiments across small percentages of users, and most tests never reach a full launch. Advertisers checking their own accounts should not expect to see the layout consistently, if at all.

The test also includes at least two related variations. One version drops the horizontal line on the left but keeps the line-by-line listing. That variant resembles layouts Google has tested before. A third variation adds images inside the Sitelinks themselves — a format Clark noted he had not previously seen, suggesting the image-based version may be a genuinely new experiment rather than a re-run of an older design.

For advertisers running text ads on mobile, the design matters for a straightforward reason: Sitelinks are one of the larger click-real-estate levers in a standard responsive search ad. A vertical, line-by-line layout takes up more vertical space in the snippet than a compact horizontal row. If Google ships it, ads with four or more Sitelinks could occupy noticeably more screen space on mobile results pages, potentially pushing organic listings further down — a familiar dynamic for SEO teams tracking paid-vs-organic displacement in commercial verticals like retail, travel, and local services.

The image-in-Sitelinks variation, if it graduates from testing, would give advertisers a richer format closer to what shopping-style listings already offer. It also raises questions about which asset types Google would pull from — ad assets advertisers upload directly, or something generated automatically.

Neither Google's ads product team nor its search liaison accounts have commented publicly on the test, and there is no documentation in Google Ads help pages referencing the new layouts.

Google's Sitelinks experiments have been a steady drumbeat over the past several years, covering everything from font changes to box treatments to expanded link counts. This latest round fits that pattern: incremental visual iterations rather than a functional change to how Sitelinks are triggered or ranked.

For advertisers and SEOs, the practical next step is monitoring. Watch whether the line-by-line layout with the left margin, the no-line variant, or the image-in-Sitelinks format appears across broader user samples in the coming weeks — broader appearance would signal the test is moving beyond the initial experiment bucket toward a wider rollout.