1,800 pages deindexed overnight despite clean GSC signals
Summary
A WordPress gaming blog publishing 3-5 posts daily lost all 1,800+ indexed pages over five days. GSC showed no errors, blank Google-selected canonicals on every page, and 'Crawled - currently not indexed' at scale.
The poster assumed a technical cause, but the r/TechSEO community and Google's own documentation point to a quality or spam signal. Gary Illyes has said directly that site quality perception drives mass 'crawled but not indexed' spikes.
The tell: technical deindexation shows specific error statuses and affects URL patterns, with Bing also affected. A quality hit shows green crawl signals, site-wide 'crawled - currently not indexed,' and Bing still indexing normally. If that is what you see, start with content quality and update timing, not canonicals.
What happened
A gaming blog publishing 3-5 posts daily lost all 1,800+ indexed pages from Google over five days. By May 5, the site went from 1,500+ indexed pages to zero.
GSC showed nothing wrong. No manual action, no security issues, no crawl errors. Every URL fetched successfully. Robots.txt was clean. But 1,015 pages sat at “Crawled - currently not indexed,” Google-selected canonical was blank on every page, and Bing was still indexing the site fine.
The poster asked r/TechSEO for help debugging canonicals and sitemaps. The community saw something different. Multiple commenters pointed to Google’s March 2026 spam and core updates, citing formulaic content, no visible author expertise, and a volume that looks like scaled content. One commenter put it bluntly: “no single human in sight, not even on the about page.”
Why it matters
When GSC shows green checkmarks everywhere but pages are disappearing, the natural instinct is to dig into technical causes. But “Crawled - currently not indexed” at scale is almost never a crawl problem. Google’s How Search Works page lists “quality of the content” as an explicit reason a crawled page won’t be indexed.
Gary Illyes said this directly at SERP Conf 2024: “the general quality of the site, that can matter a lot” in how many “crawled but not indexed” entries you see. He added that mass deindexation often happens “just because our perception of the site has changed.”
The blank canonical is a red herring. When it appears site-wide alongside mass deindexation, it is a symptom, not a cause. Google didn’t fail to extract the canonical tag. It chose not to index the page, so there is no canonical to assign.
The problem is that GSC doesn’t tell you why a page wasn’t indexed. “We couldn’t process it” and “we chose not to index it” both show up the same way. That is why practitioners end up chasing technical ghosts when the answer is in the content.
The timing fits. Google’s March 2026 spam update rolled out March 24-25, the core update followed March 27 through April 8. The poster described a slow March decline and a sharp April drop, which lines up.
How to tell: technical vs. quality
Technical deindexation shows specific error statuses in GSC: server errors, redirect loops, “noindex detected,” “blocked by robots.txt.” It hits URL patterns (a subdirectory, a template, a parameter) rather than the whole site. Bing is usually affected too, because the technical problem blocks all crawlers.
Quality-driven deindexation looks like this case: all crawl signals green, “Crawled - currently not indexed” across the board, blank canonicals site-wide, and Bing still working. The timeline matches a core or spam update.
Fastest check: is Bing still indexing you? If yes, the content is technically fine. Google just doesn’t want it.
What to do
When mass “Crawled - currently not indexed” appears alongside clean crawl signals, start with quality, not technical debugging.
Check update timing. Compare your drop against the Search Status Dashboard. If it lines up with a core or spam update, that is your working hypothesis.
Look at your content honestly. 3-5 posts a day is scaled-content territory regardless of whether AI wrote it. Does each post show genuine expertise? Is the author a real person? Would this content exist if search engines didn’t? Google’s quality guidelines spell out what “helpful content” means.
Don’t fix the blank canonical. It is a consequence of deindexation, not its cause. Rewriting your canonical tags won’t make Google re-index pages it dropped for quality.
Rule out technical causes quickly, then stop. Check robots.txt, confirm your sitemaps generate correctly, look for accidental noindex directives. If those are clean, the rest of the investigation is about content, not infrastructure. As Gary Illyes put it: when “crawled but not indexed” is climbing, the most likely reason is that Google’s perception of your site has changed.