How to Fix DNS Resolution Error in TypeScript

When your TypeScript app throws a DNS Resolution Error, it can be frustrating. Let's look at why this happens and how to resolve it.

Root Cause

DNS resolution errors in TypeScript occur when the runtime can't resolve a hostname to an IP address. This may be caused by misconfigured DNS servers, IPv6/IPv4 issues, network connectivity problems, or transient DNS cache failures.

Step-by-Step Fix

The key is to force IPv4-first DNS and wrap fetch with an AbortController timeout:

import dns from "dns";
dns.setDefaultResultOrder("ipv4first");

const controller = new AbortController();
const timeout = setTimeout(() => controller.abort(), 8000);

try {
  const res = await fetch(url, { signal: controller.signal });
  clearTimeout(timeout);
  return await res.json();
} catch (err) {
  clearTimeout(timeout);
  if (err.name === "AbortError") throw new Error("DNS/network timeout");
  throw err;
}

Common Pitfall

A systematic approach works best here: isolate the failing component, verify its inputs, check the TypeScript docs for breaking changes, and test the fix in an environment that mirrors production. As a follow-up, set up automated tests that would catch this regression. Even a simple smoke test can prevent this from reappearing after a dependency update.

Validate the Solution

Verify by triggering the same action that caused the original error. In TypeScript, you can also enable verbose logging temporarily to confirm the fix is applied correctly. Once verified, remove or reduce the logging level to keep your logs clean in production.

Stay Ahead of Errors

Want to catch errors like this before they reach production? [Bugsly](https://bugsly.dev) provides real-time error tracking for TypeScript applications.