Why SEO regression monitoring matters — and why Bing matters more than it used to

What an SEO regression is

An SEO regression is a drop in how visible your site is in search — fewer clicks, fewer impressions, fewer pages in the index, lost rich results — caused by a change rather than by the market. It is the search-side twin of a software regression: something worked yesterday, and a change broke it.

Google's guide to debugging traffic drops lists the usual causes: algorithmic updates, technical issues, security issues, spam issues, seasonality, and site moves or migrations. Only some of those are yours to fix — and the technical ones are the ones you can fix fastest, as long as you know about them.

Most of the drops you can fix are self-inflicted

The technical causes are mundane. A staging noindex setting that went live. A robots.txt Disallow that blocks a folder you still need. A canonical tag that points every product at the home page. A sitemap plugin update that dropped half the URLs. A server or firewall that answers search engines with errors.

Google is forgiving with a brief outage and unforgiving with a long one. Its documentation says 5xx and 429 errors make its crawlers slow down, and URLs that keep failing are eventually dropped from the index. If robots.txt itself returns a server error, Google stops crawling the site for 12 hours and then works from the last copy it could read.

A site-wide problem shows up fast. A page-level one — a misplaced noindex on one template — shows up as a slow slide that's easy to mistake for seasonality. That's exactly the kind of drop a monthly look at Search Console misses.

Relvato's SEO integrity check watches the settings behind these — noindex, robots.txt, canonical — every time the site changes.

Why a monthly look at Search Console isn't enough

Search Console has the data, but its numbers are final only 2–3 days later, and a drop is hard to spot by eye among weekends, holidays and ordinary noise. By the time a monthly report shows it, a month of traffic is gone.

Monitoring fixes the timing and the noise. Compare the last seven days with the same days of the weeks before, so a Sunday is measured against Sundays. Leave out sites and pages too small to judge. Require a drop to hold before calling it one. And keep a list of what changed on the site — updates, deploys, settings — so a drop comes with its likely cause.

Core update, or your own change?

Google's core updates move whole niches at once. Its Search Status Dashboard lists them, and Google's advice is to wait until an update has finished rolling out, give it a week, and then compare with the week before it started — a small drop typically needs no action.

A drop that starts the day after a plugin update, a deploy or a new robots.txt rule is a different story. That's why the timeline matters more than the chart: a drop with nothing changed on your side points to the update; a drop that follows a noindex points to you.

Why Bing matters more than it used to

Bing is a small share of searches — about 4.5% worldwide across all devices, and nearly 9% on desktop, by StatCounter's August 2026 figures. For years that made it an afterthought. What has changed is how far its index reaches beyond its own search box.

Microsoft Copilot searches the web with Bing. DuckDuckGo says its traditional links largely come from Bing, and Yahoo's results have been powered by Bing for years. And OpenAI's documentation names Bing among the search providers ChatGPT search uses, alongside its own crawler, OAI-SearchBot.

That last point needs care: Bing isn't ChatGPT's only source, and OpenAI doesn't tell site owners to register with Bing. But a page that falls out of Bing's index loses one of the ways AI assistants find it — and hardly anyone checks Bing Webmaster Tools every week. Bing also supports IndexNow, which tells Bing and several other engines about a changed page at once; Google doesn't use it.

Before any of this, AI crawlers have to be able to reach you at all — see why AI bots can't crawl some sites.

What to watch, on both engines

On Google: clicks and impressions against your own usual, by device, country and search type; the number of pages that show in results; your key pages' index status, canonical and rich results, with URL Inspection; the pages and queries losing the most ground; and sitemap errors. AI Overviews and AI Mode are counted inside Search Console's web totals.

On Bing: the pages in its index; what its crawler ran into — server errors, DNS failures, timeouts, robots.txt blocks, malware flags; clicks and impressions where there's enough traffic; and sitemaps, including old http:// copies that linger after a move to https.

Neither engine's API reports AI-answer visibility on its own yet — both show it only in their dashboards. Relvato does the rest for both: Google Search Console monitoring and Bing Webmaster Tools monitoring read your numbers once a day, read-only, and name what changed on the site before a drop.