# Template Dependency Tracking

URL: /docs/building/performance/template-deps/
Section: performance
Tags: performance, incremental, templates

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Template Dependency Tracking When you edit a template, Bengal rebuilds only the pages that use it — not every page on the site. This is automatic and requires no configuration. How It Works During each build, Bengal records which templates each page uses, including the full extends and include chain: about.md → single.html → base.html, partials/nav.html, partials/footer.html blog/post-1.md → blog/single.html → base.html, partials/nav.html On the next build, if partials/nav.html changes, Bengal rebuilds every page that depends on it (directly or transitively). Pages that don't use partials/nav.html are skipped entirely. When It Applies Scenario Behavior Edit a content file Normal incremental: only that page rebuilds Edit a template Selective: only pages using that template rebuild Edit a base template Broader selective: all pages extending it rebuild First build (no cache) Full build; dependencies recorded for next time Cache miss Falls back to full rebuild Performance Impact On a 1,000-page site where you edit a partial used by 50 pages: Without template deps: all 1,000 pages rebuild With template deps: only 50 pages rebuild The dependency data is stored in the build cache alongside content hashes. The lookup is O(1) per template via a lazy reverse index. Interaction with Dev Server Template dependency tracking works with bengal serve. When you save a template file, the dev server triggers a selective rebuild and hot-reloads only the affected pages. See Also Performance Overview — All optimization strategies Free-Threading — Parallel rendering

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- Author: lbliii
- Word Count: 237
- Reading Time: 1 minutes