Start by typing your domain followed by /sitemap.xml into a browser address bar. If you see structured XML with URL entries, you've found it. WordPress sites with Yoast or RankMath typically serve sitemaps at /sitemap_index.xml, Shopify uses /sitemap.xml, and custom setups may place them elsewhere or define the path in robots.txt. Once located, submit the sitemap URL in Google Search Console under Index > Sitemaps. GSC shows how many URLs you submitted versus how many Google indexed, flags errors like unreachable URLs or incorrect formatting, and tells you the last fetch date. If you see a large gap between submitted and indexed counts, investigate those URLs for noindex tags, canonicals pointing elsewhere, or redirect chains. Use an XML sitemap validator to catch structural problems. Tools like xml-sitemaps.com/validate or the W3C validator check for malformed XML, missing required tags, URLs exceeding 50,000 per file, or file sizes over 50 MB uncompressed. Common mistakes include listing non-canonical URLs, including 404s or redirects, forgetting lastmod dates, or submitting URLs blocked by robots.txt. For larger sites, check if you have a sitemap index file that references multiple sitemaps split by content type or date. Crawl your sitemap with Screaming Frog or Sitebulb to verify every listed URL returns 200, is indexable, and matches your intended structure. Compare the sitemap URL count against your actual page count—if they're wildly different, your sitemap generation logic might be broken. At Ottawa SEO, we audit sitemaps during every technical review. We've seen enterprise clients with 80,000-URL sitemaps where 30% were soft 404s, and small businesses submitting the same 12 pages across four redundant sitemap files. Clean sitemaps don't guarantee indexing, but messy ones waste crawl budget and obscure real issues. Check yours monthly, especially after site migrations, CMS updates, or bulk content changes.