Free ToolLarge-Site SEOClient-Side

Sitemap Builder & Splitter

Generate valid, chunked sitemap.xml files and a sitemap_index.xml—all in your browser. Enforce the 50k URL and 50 MB limits, optionally GZIP each part, and download a single ZIP.

Split by 50k URLs and 50 MB caps
ZIP with index & all parts
No upload — runs locally
URLs Input
URL Governance
Defaults (optional)
Row-level values from CSV override these defaults.
Splitting & Limits
Hard-capped at 50,000 per spec
We also enforce a 50 MB maximum per part.
Index Location (optional)
If blank, the index will reference filenames only.
Build
Debug & Tests (local)

Who is this for?

Fast-Changing Sites

Ecommerce, marketplaces, news, UGC—where thousands of URLs shift weekly.

Migrations & Replatforming

Emit clean sitemaps to speed re-indexing and validate coverage.

Headless & Agencies

When plugins are not enough and you need strict control.

How it works

  1. Paste URLs or upload CSV (url,lastmod,changefreq,priority).
  2. Choose governance (force HTTPS, trailing slash mode, de-dupe) and defaults.
  3. Split with caps: ≤50,000 URLs & ≤50 MB per file. Optional .xml.gz.
  4. Download a ZIP with sitemap_index.xml and all parts.
Tip: Host the ZIP contents at /sitemaps/ (or any folder) and submit the index to Search Console.
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If you’re not in a position to support us, that’s okay. Postly will still be here for you. But if you are one of the few who can chip in, your support directly keeps these tools online for everyone else.