Sitemap lastmod vs IndexNow for recrawl signaling

Sitemap lastmod vs IndexNow for recrawl signaling

Two ways to tell engines "this changed, come back." Use both, but know what each does.

1. Sitemap lastmod: passive pull signal. Google reads it on its own schedule; honest lastmod gently nudges recrawl priority. Slow, but zero per-URL cost.
2. IndexNow (Bing, Yandex, others — not Google): active push. You ping the moment a URL changes; near-instant recrawl on supporting engines.
3. Decision rule: bulk steady-state freshness → trustworthy lastmod. Time-sensitive single-URL updates (price drop, new data) → push via IndexNow for the engines that honor it.
4. Guardrail: don't fire IndexNow on cosmetic changes — abuse gets your key throttled. Only ping on meaningful content change.
5. Guardrail: lastmod that updates on every build (even with no content change) trains Google to ignore it. Gate: lastmod derives from content hash, not deploy time.

Rollback: both signals are advisory; stop sending, no harm done.

Ship gate: don't publish until all boxes are checked.