# Link checking > Speed up external link checking with lean-render builds for checkers --- LLMS index: [llms.txt](/llms.txt) --- A link checker that crawls your built site re-checks the repeated, auto-generated _[chrome][]_ — the navbar, footer, and left-nav — on _every_ page, even though those links are often identical site-wide. On a large site that's the bulk of the work, and it inflates checker output. **Lean render** is a build mode that omits the repeated chrome from the output, so a checker reaches each link once instead of once per page. It works with any external link checker, needs no extra post-build pass, and keeps just enough instances of each region to keep its repeated links reachable: - **Navbar and footer**: kept on each locale's home page. Their links are config-defined and the same across the locale, except for the navbar's language selector (and an optional version menu) — see the caution. - **Left-nav** (computed per page): kept on each locale's docs landing page, which carries the full docs tree. On a [doc-rooted site][doc-rooted], that landing page _is_ the home page. The navbar's language selector points to each page's own translation rather than a fixed target, but those translations are docs pages that the destination locale's left-nav already covers, so the single kept navbar loses no reachable link. Dropping the repeated chrome also makes a lean build a much less noisy basis for diffing generated output: changes to a shared region show up once, instead of on every page, so a diff surfaces the content that actually changed.

Caution

Lean render is an [experimental][] optimization that rests on assumptions about how chrome repeats, which may not hold for every site. Use it only for link-checking builds and run full-site link checks as well, even if less often. One known case: a navbar [version menu][version-menu] with `version_menu_pagelinks` enabled emits per-page links, which lean render's single kept navbar won't cover. Refining support for such cases is future work.

## Enabling lean render Set the `td.lean_render` parameter to `remove`:

[params.td]
lean_render = "remove"

params:
  td:
    lean_render: remove

For a link-checking CI job, it's usually cleaner to set it through the environment instead, leaving your committed config untouched: ```sh HUGOxPARAMSxTDxLEAN_RENDER=remove hugo ``` Use a non-underscore delimiter (`x` above), not `HUGO_PARAMS_TD_LEAN_RENDER`: Hugo treats every `_` after the `HUGO` prefix as a key separator, which would split the `lean_render` key. See Hugo's [configuration with environment variables][hugo-env-config]. The value names the mode. Only `remove` is implemented; any other or empty value leaves the chrome in place. [chrome]: https://www.nngroup.com/articles/browser-and-gui-chrome/ [doc-rooted]: /docs/content/adding-content/#doc-rooted-sites [experimental]: /project/about/changelog/#experimental [hugo-env-config]: https://gohugo.io/getting-started/configuration/#configure-with-environment-variables [version-menu]: /docs/content/versioning/#adding-a-version-drop-down-menu