SOP: Gzip large sitemaps the right way

SOP: Gzip large sitemaps the right way
For files near the size ceiling.

Step 1 — Compress only when needed: file approaching ✅ 50 MB uncompressed. Small files don't need it.

Step 2 — Name it ✅ ending in .xml.gz (the extension matters to crawlers).

Step 3 — Serve with header ✅ Content-Type: application/x-gzip (or text/xml + Content-Encoding: gzip — pick one scheme, not both).

Step 4 — Reference the .xml.gz URL in your sitemap index by its full absolute path.

Step 5 — The 50,000-URL limit still applies AFTER decompression. ✅ Gzip does not raise the URL cap.

Step 6 — Test: download it, gunzip, run xmllint. ✅ Valid XML inside.

Definition of done: .gz fetches with correct headers, decompresses to valid XML under 50k URLs, and GSC reads it without a 'parse error'.