Both input and output matter. That's settled, and being told it isn't much use, because the practical question is when.
Start production too early and there's nothing to produce. Leave it too late and you spend years adding to a store you never use. Most people err heavily in one direction.
The Test
It's simpler than it looks. Can you understand considerably more than you can say?
If yes, you have material sitting unused and you're ready. If the two are roughly level — you understand little and say little — you're still in the foundation stage and more input is the right call.
Almost everybody who has been at this a while fails that test in the same direction. Comprehension well ahead, production near zero. That gap is the signal, and in most cases it has been open for years.
What "Ready" Actually Requires
Less than people assume.
A few hundred words you'd recognise, a rough sense of how sentences go, and an ear that has adjusted to the sound of the language. That's a few months of casual input for most adults — and if you've done school languages or an app for any length of time, you passed this point a while ago.
You don't need to have finished anything. There's no completion requirement.
Why More Input Stops Paying
Past the foundation stage, additional input keeps improving comprehension and does essentially nothing for production. The two abilities run on separate systems, and one doesn't feed the other automatically.
So the returns don't stop. They just stop landing anywhere near the thing you're waiting for. You get better at understanding, which you already do well, while the speaking stays exactly where it was.
Not Instead Of — After
The switch isn't an abandonment. Input carries on being useful, and most people keep doing some indefinitely because it's enjoyable and it feeds new material in.
What changes is where the emphasis sits. Foundation first, then conversion, then both together for as long as you like.
If You're Not Sure
You almost certainly are ready. Nearly everybody asking the question has been ready for a considerable time — the uncertainty is usually about confidence rather than about material.
About Outputly
Outputly is the conversion stage. If you understand more than you can say, you already have everything it needs — and you can keep whatever input you're enjoying alongside it.