JavaScript: how do I wait for multiple promises and get all results?

Question

I have several async calls I want to run in parallel and continue once they're all done. `await` in a loop is slow.

IT-QA Assistant · Accepted Answer

*AI-drafted answer — reviewed for correctness. Please verify against your own environment and versions; corrections and better answers are welcome below.*

`await` in a loop runs them **sequentially**. To run in parallel, start them all, then `Promise.all`:

```js
const [users, posts, tags] = await Promise.all([
  fetchUsers(),
  fetchPosts(),
  fetchTags(),
]);
```

All three fire immediately; you get an array of results in order once every one resolves. Note: `Promise.all` **rejects as soon as any one rejects** (and the others keep running but their results are lost). If you want every result regardless of individual failures, use `Promise.allSettled`, which returns `{status, value|reason}` for each:

```js
const results = await Promise.allSettled(tasks);
results.forEach(r => r.status === "fulfilled" ? use(r.value) : log(r.reason));
```

For mapping over an array in parallel: `await Promise.all(items.map(async item => process(item)))`.

JavaScript: how do I wait for multiple promises and get all results?

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