Is Vertex AI Search a replacement for Google index checks?
When Google closed the Custom Search JSON API to new customers, it named Vertex AI Search as the alternative for searching across up to 50 domains. Many people read that as "the new way to check indexing". It is not. Vertex AI Search is built to search content you configure, and that is a different job from asking whether Google Search has a URL in its index.
What Google actually recommends
The Custom Search JSON API overview says the API is closed to new customers and that existing customers have until January 1, 2027 to move. For customers who need to search across up to 50 domains, it suggests Vertex AI Search. The recommendation is aimed at sites that used Programmable Search to power a search box or a small vertical search engine.
Why it does not replace an index check
An index check asks a narrow question about Google Search: for this exact URL, does Google have it in the index right now? Vertex AI Search does not answer that question. It answers user queries over the data you connected to it — your sites, your documents — using its own retrieval. Even when a page shows up in a Vertex AI Search result, that tells you the page is in your search app's data, not that it is in Google's web index.
There is also the domain limit. Backlink checks usually involve hundreds of different domains: blogs, directories, profiles, forums. A product built around a configured set of up to 50 domains does not map onto that list.
When Vertex AI Search is the right move
- You run a site search box that used Programmable Search Engine through the JSON API, and you need it to keep working after the deadline.
- You search across a fixed group of your own sites — a company's brand sites, a documentation portal and a blog, for example.
- You want answers over your own content rather than links to Google's public results.
What to use for index checks instead
Split the job by ownership, the same way as in the overview of index check methods:
- Your own pages: the URL Inspection API, within its daily quota per property.
- Pages on other sites: a dedicated index checker that accepts any list of URLs.
- A quick sanity check: the site: operator, keeping in mind that its results are not complete.
For a compact summary of these options after the shutdown, see an overview of index checker options published as a short visual guide.
Questions to ask before you migrate
- What did the old integration return to users? If it was a list of search results on your site, look at Vertex AI Search. If it was a status column in a report, look at index checkers.
- Whose domains are involved? Your own sites fit Vertex AI Search and Search Console. Third-party domains fit neither.
- How many URLs per day? Small daily volumes on your own property fit the URL Inspection API. Large lists of external URLs need a bulk tool.
- Who maintains it? A managed search product, an API integration and a script each need a different owner on your team.
Guides on this site
- Check Google index status without the Custom Search API — the overview and how to choose a method.
- URL Inspection API limits — 2,000 inspections per property per day and the scope rule.
- Vertex AI Search for index checks — what Google's suggested alternative is built for.
- The site: operator as an index check — what it shows and what it misses.
- Bulk index check in Python — a safe script structure with batches and retries.
FAQ
Is Vertex AI Search the official replacement for the Custom Search JSON API?
Google suggests it for customers who need to search across up to 50 domains. It is a replacement for site search use cases, not for index status reports.
Can Vertex AI Search tell me whether a backlink is indexed?
No. It searches the content you configure. It does not report Google Search index status for pages on other sites.
Sources
https://developers.google.com/custom-search/v1/overview