IndexNow is a protocol that lets websites instantly notify search engines about new or updated content. Supported by Bing, Yandex, Naver, and Seznam.
Traditional search engine crawlers visit sites on their own schedule, sometimes weeks or months between visits. IndexNow inverts that — the website pings the search engine via a simple HTTP POST request whenever content changes, prompting near-immediate re-crawl. Content typically appears in supporting search engines within hours or days instead of weeks. Each domain hosts a key file at the root (a randomly-generated UUID-based filename) for verification.
A blog publishes a new post at /blog/new-article/. The publishing system sends a POST request to api.indexnow.org with the URL list and the site's key file URL. Bing, Yandex, Naver, and Seznam crawl the URL within hours instead of waiting for their next scheduled visit. Google does NOT use IndexNow but uses similar Google-only signals via Google Search Console.
IndexNow vs sitemap.xml submission: Sitemaps are batch references to all URLs; IndexNow is targeted notification of specific changes. Both are useful. IndexNow vs Google's URL Inspection: Google's URL Inspection in Search Console allows manual single-URL re-index requests; IndexNow is a programmatic mass-notification API.