The JavaScript Promise.allSettled() method
The Promise.allSettled() method waits for all promises to finish and returns an array describing each outcome — { status: "fulfilled", value } or { status: "rejected", reason }. Unlike Promise.all(), it never rejects, so one failure doesn't lose the other results.
Overview
Promise.allSettled() runs several promises in parallel and waits for every one to settle — fulfill or reject — then hands you an array reporting what happened to each. Each entry is an object: { status: "fulfilled", value } for successes and { status: "rejected", reason } for failures.
The key difference from Promise.all() is that it never rejects. Promise.all() fails fast — one rejection discards all results — which is wrong when you want every operation's outcome regardless of individual failures. Loading several independent widgets, sending a batch of requests, settling a list of uploads: you want to know which succeeded and which failed, and that's exactly what allSettled() gives you.
Because results come back uniformly (no throw), you process them by checking status: filter the "fulfilled" ones for their values, the "rejected" ones for their errors. It pairs with the rest of the Promise combinators — all() (all must succeed), race() (first to settle), and any() (first to fulfill).
Syntax
const results = await Promise.allSettled([p1, p2, p3]);
results.forEach(r => {
if (r.status === "fulfilled") console.log(r.value);
else console.log("failed:", r.reason);
});Parameters
The Promise.allSettled() method accepts the following parameters.
| Parameter | Description |
|---|---|
iterable |
An iterable (usually an array) of promises. Resolves to an array of { status, value } / { status, reason } objects. |
Example
<pre id="out" style="font:14px ui-monospace,monospace"></pre>
<script>
const ok = (v) => Promise.resolve(v);
const fail = (e) => Promise.reject(e);
Promise.allSettled([ok('A'), fail('boom'), ok('C')]).then(results => {
document.getElementById('out').textContent =
results.map(r =>
r.status === 'fulfilled' ? 'ok: ' + r.value : 'err: ' + r.reason
).join('\n');
});
// ok: A / err: boom / ok: C
</script>Best practices
- Use
allSettled()when you want every result, even if some promises reject. - Use Promise.all() instead when any failure should abort the whole batch.
- Process results by checking each
status("fulfilled"vs"rejected"). - It never rejects, so you usually don't need a try...catch around it.
Frequently asked questions
What is the difference between Promise.all() and Promise.allSettled()?
allSettled() waits for all and reports each outcome, never rejecting.When should I use Promise.allSettled()?
How do I read the results of allSettled()?
status: check for "fulfilled" (with value) or "rejected" (with reason).