What each protocol actually does
Three different mechanisms, often confused:
- XML Sitemap: A file on your server listing your URLs. Search engines fetch it periodically (Google: every few days to weekly). Passive discovery — you publish, they get around to it.
- Google Indexing API: A direct HTTPS endpoint. You POST a URL, Googlebot priority-fetches it within minutes. Active push — only Google.
- IndexNow: An open protocol supported by Bing, Yandex, Seznam, Naver, and others (but NOT Google). You POST a URL, all participating engines hear about it.
Speed comparison: real numbers
| Protocol | Avg time to crawl | Avg time to index | Search engines |
|---|---|---|---|
| XML Sitemap discovery | 1–14 days | 1–21 days | All |
| Sitemap with lastmod bump | Hours – 3 days | Hours – 7 days | All |
| Google Indexing API | 30 seconds – 5 minutes | 1–10 minutes | Google only |
| IndexNow | Minutes – hours | Minutes – hours | Bing, Yandex, Seznam, Naver |
| Stacked (all three) | 30 seconds (Google) | 30 seconds – 1 hour | All |
Submission limits
| Protocol | URLs per request | Daily quota | Notes |
|---|---|---|---|
| XML Sitemap | 50,000 URLs / 50 MB | Unlimited | Passive — engines fetch on their schedule |
| Google Indexing API | 100 URLs (batch) | 200 URLs/day default | Quota increase available on request |
| IndexNow | 10,000 URLs | Effectively unlimited | Each engine has its own throttle |
Coverage: which engines see what
This is where IndexNow and the Google Indexing API are not interchangeable. They cover different markets:
- Google Indexing API: Google (90%+ global search share in most Western markets).
- IndexNow: Bing (~3%), Yandex (~40% in Russia), Seznam (~25% in Czechia), Naver (~50% in South Korea), plus DuckDuckGo and Ecosia downstream from Bing.
- XML Sitemap: All engines, but at their own pace.
TIP
If your audience is 95% English-speaking, US/EU-based, prioritize the Google Indexing API and accept that Bing will lag. If you target Russia, Korea, or Czechia specifically, IndexNow is non-negotiable.
When to use which (decision tree)
- Do you need Google indexing in under 5 minutes? → Google Indexing API.
- Do you need Bing, Yandex, or other non-Google engines? → IndexNow.
- Do you publish more than 100 URLs/day to Google? → Stacked indexer (combines API + IndexNow + queueing).
- Are you publishing fewer than 5 URLs/week? → Just keep your sitemap fresh; the speed gain isn't worth the setup.
Setup cost and complexity
| Protocol | Setup time | Ongoing maintenance |
|---|---|---|
| XML Sitemap | 10 minutes (most CMSs auto-generate) | None |
| Google Indexing API direct | 1–2 hours (service account, OAuth, code) | Monitor quota, retry on failure |
| IndexNow direct | 30 minutes (key file upload, code) | Low |
| Instant URL Indexer (wraps both) | 5 minutes (API key) | None |
The optimal 2026 stack
For most professional sites, the answer isn't "pick one." It's all three, layered:
- Sitemap as the baseline. Auto-generated, kept fresh, submitted in Search Console and Bing Webmaster Tools.
- Google Indexing API on every new URL the moment it's published. Priority crawl within minutes.
- IndexNow on the same publish event. Bing and Yandex see it in parallel.
- Track every submission. Re-submit URLs that didn't index on the first attempt.
Instant URL Indexer is built around this exact stack. One API call (or one paste-in submission) hits Google's Indexing API and the IndexNow protocol simultaneously, with per-URL tracking. No service account setup, no separate IndexNow key management.
Common confusion: does Google support IndexNow?
No. Google announced in 2021 that they were testing IndexNow, but as of 2026 they have not officially joined. Google relies on its own Indexing API and on the sitemap protocol. Don't substitute IndexNow for the Google Indexing API — they cover different engines.
HEADS UP
Tool reviews that claim IndexNow indexes pages on Google are wrong. Verify by checking the search results, not the dashboard status — IndexNow's "success" status means it pinged the protocol, not that Google specifically processed it.