IndexNow is an open protocol, originally proposed by Microsoft and Yandex, that lets a site push a notification the instant a URL is created, updated, or deleted, rather than waiting for the next scheduled crawl to discover the change. Bing, Yandex, Naver, and Seznam consume IndexNow submissions; Google does not participate in the protocol as of now, which is the core reason Bing SEO requires this extra step that Google SEO does not.
Implementation requires generating a unique API key, hosting it as a plain text file at your domain root matching the key filename exactly, and then sending an HTTP GET or POST request to an IndexNow-participating endpoint with the URL and key whenever content changes. Most CMS platforms - WordPress via a plugin, Shopify via an app, or custom stacks via a webhook on publish - can automate this so no manual step is needed per article.
A single IndexNow submission to any one participating search engine's endpoint propagates to all participating engines because they share the underlying protocol infrastructure, meaning you do not need to separately ping Bing and Yandex - one correctly formatted call covers both.
IndexNow does not guarantee immediate indexing, only immediate awareness. Bing still applies the same quality and relevance gates described later in this piece before including the URL in its index; IndexNow simply removes the discovery lag, which for time-sensitive content - news, price changes, product launches - is often the difference between capturing a search moment and missing it entirely.
Verify implementation is working by checking the IndexNow section inside Bing Webmaster Tools, which logs submitted URLs and their processing status, or by submitting a test URL through Bing's public IndexNow validator and confirming a 200 response with no key mismatch errors.