Some Sites Slow, Others Fine - Is That Your Router?

🔧Step-by-Step Fixes

Understanding Selective Slowness

When some sites are fast and others are slow, it's rarely your router causing the problem. Here's why:

Reason 1: The Website's Server Location and Capacity

Not all websites have the same infrastructure:

• Big sites like YouTube, Netflix, and Facebook have servers distributed globally (Content Delivery Networks). There's probably a server within 50-100 miles of you.
• Small or specialized sites might have one server in one location. If that server is across the country or overseas, loading will be slower.
• Overloaded servers respond slowly no matter how fast your connection is.
• Poorly optimized websites might have huge uncompressed images or inefficient code that takes forever to load.

Your router delivers data equally to all sites. The speed difference is happening outside your home network.

Reason 2: ISP Routing and Peering Issues

Your internet traffic doesn't take a direct path to every website:

• ISPs have better "peering" relationships with some networks than others. Traffic to well-connected sites takes fewer hops.
• Congestion between networks can slow traffic to certain sites while others remain fast.
• Some ISPs throttle specific types of traffic or certain websites (though this is less common after net neutrality rules).

You can test this by using a VPN - if the slow sites suddenly become fast through the VPN, your ISP's routing is the problem.

Reason 3: DNS Resolution Delays

Before loading a website, your computer has to look up its IP address using DNS (Domain Name System). Some sites have slow or poorly configured DNS:

1. Open Command Prompt (Windows) or Terminal (Mac)
2. Type: nslookup slowwebsite.com and press Enter
3. Check how long it takes to respond
4. Compare with a fast site: nslookup google.com

If the slow site's DNS lookup takes several seconds, that's your answer. You can try using different DNS servers like Google DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1).

How to Change Your DNS Servers

This can sometimes improve speeds to slow-loading sites:

On Windows:

1. Go to Settings > Network & Internet > Ethernet (or Wi-Fi)
2. Click your connection, then Edit next to DNS server assignment
3. Choose Manual, turn on IPv4
4. Enter Preferred DNS: 1.1.1.1 and Alternate DNS: 1.0.0.1
5. Save and test the slow sites again

On Mac:

1. Go to System Settings > Network
2. Select your connection and click Details
3. Go to the DNS tab
4. Click + and add 1.1.1.1 and 1.0.0.1
5. Click OK and test again

Reason 4: Browser Extensions and Security Software

Sometimes the slowness is on your end but not your router:

• Ad blockers can sometimes slow down sites that have complex ad detection systems
• Security extensions scan every element on a page before displaying it
• Antivirus software with web scanning features adds latency
• VPN browser extensions route traffic through extra servers

Test in a private/incognito window (which disables extensions) or try a different browser entirely.

Reason 5: The Website Uses Security Protocols Your System Doesn't Like

Some websites use newer SSL/TLS protocols or security configurations that older devices or browsers struggle with. The extra negotiation time makes loading feel slow. Make sure your browser is up to date.

When It Actually IS Your Router

In rare cases, router issues can cause selective slowness:

• QoS (Quality of Service) settings might prioritize certain traffic types over others
• Firewall rules might inspect certain traffic more heavily
• IPv6 issues - if the router's IPv6 is misconfigured, sites that prefer IPv6 will be slow
• Failing router hardware might struggle with certain connection types

Try accessing the slow sites from a device connected directly to your modem (bypassing the router). If they're suddenly fast, your router configuration or hardware might be the issue.