Svelte · Senior · Question 60 of 75

What is the difference between `mount` and `hydrate`?

✓Correct answer: mount creates new DOM in the target; hydrate reuses server-rendered DOM and attaches behaviour to it
2They are aliases
3hydrate is only for custom elements

Explanation

Effects (including onMount) don't run during the mount/hydrate call itself; call flushSync() to run them immediately, e.g. in tests.

Further reading

Svelte: Imperative component API ↗

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