# flush

> Close outlets so a streamed page can be sent so far.

`flush` closes the [outlets](https://kilnlang.com/docs/tags/outlet/) above it. When you [stream](https://kilnlang.com/docs/api/streaming/) a page, everything up to `flush` can then be sent, instead of waiting for the render to end.

page.kiln:

```kiln
<html>
	<head>
		{% outlet "head" %}
		{% add to "head" %}
			<title>Home</title>
		{% endadd %}
	</head>
	{% flush %}
	<body>
		<h1>Home</h1>
	</body>
</html>
```

Output:

```html
<html>
	<head>
		<title>Home</title>
	</head>
	<body>
		<h1>Home</h1>
	</body>
</html>
```

`flush` outputs nothing. It closes outlets with `render` too, so a template gives the same HTML and the same errors whether you render or stream it.

## Closed outlets

- Each outlet above `flush` gets the content added to it so far, and is then closed.
- Adding content to a closed outlet is an `outlet-closed` error, because that part of the page may already have been sent.
- An `add to … once` tag that already added its content is fine, because it adds nothing new.
- Outlets below `flush` stay open.

Put `flush` after the last tag that adds to the outlets above it. Components lower in the page can add to an outlet that comes after it instead, such as one before `</body>`.

## Rules

- `flush` can be used any number of times.
- It can't be inside `cache`, `set`, `apply`, `add to` or a macro, because their content isn't part of the page yet.