ERR_NAME_NOT_RESOLVED is a fatal network-layer error indicating that the client's DNS resolver could not translate the target hostname into an IP address. In scraping pipelines, this rarely means the target site is actually down — it almost always points to a proxy node failure, a poisoned DNS cache, or an exhausted local resolver dropping UDP packets under high concurrency.
If you can't resolve the IP, you can't open the socket. Here is why DNS fails at scale and how it breaks your pipeline.
Ask a DataFlirt engineer →ERR_NAME_NOT_RESOLVED happens when a domain name lookup fails. In a local browser, it means your internet is down. In a scraping cluster, it means your proxy node failed its DNS lookup, your local DNS cache is poisoned, or you're hitting rate limits on your upstream resolver.
ERR_NAME_NOT_RESOLVED is a Chromium network stack error indicating a complete failure of the DNS resolution process. Before an HTTP request can be sent, the browser must translate the human-readable hostname (e.g., api.example.com) into an IP address. If the configured DNS resolver returns an error, times out, or says the domain doesn't exist, the browser aborts the request immediately.
In a scraping context, this error is rarely caused by the target site actually going offline. It is almost always an infrastructure failure on the scraper's side or the proxy's side.
Where the DNS lookup happens dictates how you fix the error:
DNS heavily relies on UDP port 53. When a scraping cluster spins up thousands of concurrent headless browsers, each browser attempts to resolve hostnames independently. This can quickly exhaust the OS's ephemeral port range or trigger UDP flood protection on the local network interface. The result is a cascade of dropped packets, leading to artificial ERR_NAME_NOT_RESOLVED errors even though the upstream DNS server is perfectly healthy.
We treat DNS as a critical path component, not an afterthought. Our infrastructure runs a dedicated, multi-tiered DNS caching layer. When a pipeline requests a URL, our edge resolves the hostname once, caches it globally, and passes the raw IP to the proxy fleet. This completely bypasses the unreliable DNS resolvers of residential ISPs, drops DNS latency to sub-millisecond levels, and virtually eliminates name resolution errors from our pipeline telemetry.
Chromium implements aggressive internal DNS caching. Crucially, it caches failures (negative caching) for up to 60 seconds. If a flaky proxy causes a single ERR_NAME_NOT_RESOLVED, Chromium will instantly fail all subsequent requests to that domain from that browser context without even attempting another network lookup. To recover, you must either destroy the browser context or launch with specific flags to disable the host resolver cache.
DNS resolution is a hidden bottleneck in high-throughput scraping. DataFlirt monitors resolver latency and packet drop rates to prevent artificial timeouts before the HTTP layer is even reached.
A Puppeteer script attempting to route through a residential proxy pool, failing at the DNS phase before the TCP handshake can even begin.
Ranked by frequency across DataFlirt's proxy telemetry. Most DNS failures in scraping are infrastructure issues, not target downtime.
cache aggressively, route globally.
Relying on a proxy provider's default DNS resolver is a recipe for high latency and random ERR_NAME_NOT_RESOLVED spikes. DataFlirt decouples DNS from the proxy layer. We resolve target IPs using our own distributed DNS-over-HTTPS (DoH) infrastructure, cache the records at the edge, and pass direct IP connections to the proxy pool. This eliminates proxy-side DNS failures entirely and shaves 50–150ms off every cold request.
Live telemetry of a decoupled DNS resolution flow in the DataFlirt edge.
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Common questions about DNS failures, proxy resolution, and how to debug Chromium network errors at scale.
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ERR_NAME_NOT_RESOLVED means the client couldn't find the IP address for the domain name. ERR_CONNECTION_REFUSED means the IP was found, but the target server actively rejected the TCP connection attempt on the specified port. One is a DNS failure; the other is a firewall or service failure.ERR_NAME_NOT_RESOLVED for subsequent requests to that domain until the negative cache expires.ERR_NAME_NOT_RESOLVED errors. Production pipelines should run a local caching resolver (like Unbound or CoreDNS) on the scraping cluster to absorb the query volume.20-minute scoping call. Pilot dataset within the week. Production within two. Whether you need a one-off catalogue dump or a continuous feed across millions of records — we scope, build, and operate the pipeline.