diff --git a/sites/svelte-5-preview/src/routes/docs/content/01-api/05-imports.md b/sites/svelte-5-preview/src/routes/docs/content/01-api/05-imports.md
index ca3c2fc9e1..e173da1a3d 100644
--- a/sites/svelte-5-preview/src/routes/docs/content/01-api/05-imports.md
+++ b/sites/svelte-5-preview/src/routes/docs/content/01-api/05-imports.md
@@ -6,6 +6,29 @@ As well as runes, Svelte 5 introduces a handful of new things you can import, al
## `svelte`
+### `flushSync`
+
+Forces any pending effects (including DOM updates) to be applied immediately, rather than in the future. This is mainly useful in a testing context — you'll rarely need it in application code.
+
+```svelte
+
+
+{count}
+
+```
+
### `mount`
Instantiates a component and mounts it to the given target:
diff --git a/sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md b/sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
index 0358d87cd8..1a5d571c1e 100644
--- a/sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
+++ b/sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
@@ -152,6 +152,25 @@ In Svelte 4, doing the following triggered reactivity:
This is because the Svelte compiler treated the assignment to `foo.value` as an instruction to update anything that referenced `foo`. In Svelte 5, reactivity is determined at runtime rather than compile time, so you should define `value` as a reactive `$state` field on the `Foo` class. Wrapping `new Foo()` with `$state(...)` will have no effect — only vanilla objects and arrays are made deeply reactive.
+### Events and bindings use delegated handlers
+
+Event handlers added to elements with things like `onclick={...}` or `bind:value={...}` use _delegated_ handlers where possible. This means that Svelte attaches a single event handler to a root node rather than using `addEventListener` on each individual node, resulting in better performance and memory usage.
+
+Additionally, updates that happen inside event handlers will not be reflected in the DOM (or in `$effect(...)`) until the browser has had a chance to repaint. This ensures that your app stays responsive, and your Core Web Vitals (CWV) aren't penalised.
+
+In very rare cases you may need to force updates to happen immediately. You can do this with `flushSync`:
+
+```diff
+
+```
+
## Other breaking changes
### Stricter `@const` assignment validation