.tip

Promise.all rejects on the first failure and throws away the other results, even the ones that succeeded. For a fan-out where partial results are still useful, allSettled gives you every outcome.

const results = await Promise.allSettled(urls.map(fetchJson));
const ok = results.flatMap((r) => (r.status === "fulfilled" ? [r.value] : []));

Use all when the results only mean something together, and allSettled when you'd rather have nine out of ten.