Why Is My Internet Slow When Speed Tests Say It's Fast? — Tek Answers #1

Short answer: A speed test measures raw bandwidth between your device and a nearby test server. Real-world browsing depends on latency, routing, Wi-Fi, device load, ISP policies, and the destination server — and any one of those can make a fast connection feel slow.

What's actually being measured?

A typical speed test reports download, upload, and sometimes ping (latency). Those numbers tell you the maximum throughput under test conditions — not the whole story for daily browsing, streaming or gaming.

7 common reasons your internet feels slow despite a high speed-test number

  1. High latency (ping): Pages and games need low latency. Even with 100 Mbps download, a 200 ms ping makes things feel sluggish.
  2. Wi-Fi problems: Weak signal, channel interference, or old routers reduce real throughput and cause retransmits.
  3. Network congestion: Many users/streaming devices at the same time or ISP congestion in your area reduce effective speed.
  4. Server-side limits: The site or service you're contacting might be slow or limited — speed tests use optimized servers; real sites often don’t.
  5. Background apps / updates: Cloud sync, OS updates, torrents, or mobile backups can silently eat bandwidth.
  6. Router/firmware or DNS issues: Old firmware, bad DNS, or misconfigured QoS can cause slow responses.
  7. ISP shaping or throttling: Some ISPs limit throughput for certain services (P2P, streaming) or after a usage threshold.

Quick diagnostics — do these checks (5–10 minutes)

  1. Run two tests: 1) Wired test — connect laptop by Ethernet and run a speed test (speedtest.net). 2) Wi-Fi test — same test over Wi-Fi. Compare results. Big difference → Wi-Fi issue.
  2. Check latency: Open a terminal / command prompt and run: 
    ping 8.8.8.8 -n 10   (Windows)
ping 8.8.8.8 -c 10   (macOS/Linux)
    If average RTT is >50 ms for local usage (or spikes >100 ms), latency might be the problem.
  3. Traceroute: Identify slow hops: 
    tracert google.com   (Windows)
traceroute google.com (macOS/Linux)
    Slow or failing hops near the start → local network/router. Slow hops in the middle or end → ISP or remote server.
  4. Check device load: Open Task Manager (Windows) or Activity Monitor (macOS) and look for apps using network heavily (browser tabs, cloud backups, torrent clients).
  5. Check DNS: Try a fast public DNS temporarily — e.g., Google (8.8.8.8) or Cloudflare (1.1.1.1) — slow DNS can make page loads lag even if bandwidth is fine.

Practical fixes you can do now

  • Restart modem & router: The classic: power-cycle both devices, router first, modem after 30s.
  • Use wired Ethernet: For tests and for gaming/streaming, wired is far more consistent than Wi-Fi.
  • Move / upgrade your router: Place router centrally, away from microwaves or thick walls; upgrade if >5 years old.
  • Change Wi-Fi channel: Use a Wi-Fi analyzer (phone apps exist) to pick a less crowded 2.4 GHz/5 GHz channel.
  • Limit background sync: Pause cloud backups, software updates, and torrent uploads during critical usage.
  • Switch DNS: Use 1.1.1.1 or 8.8.8.8 and test page load speed improvement.
  • Enable QoS on router: If available, prioritize gaming or streaming traffic over downloads.
  • Contact your ISP: If traceroute shows ISP backbone latency or repeated packet loss, file a support ticket with the traceroute logs attached.

Advanced checks (if you’re comfortable)

These give deeper evidence if the problem persists.

  • Run MTR (my traceroute) for continuous path monitoring (Linux/macOS or via WSL). It shows packet loss per hop over time.
  • Check router logs for errors, restarts, or high CPU usage.
  • Temporary VPN test: If a VPN improves speeds to a problematic site, this suggests ISP routing/throttling issues. Use this as a diagnostic only, not a long-term fix.

One-page checklist (copy & paste this in your notes)

  • ☐ Speed test (Ethernet) — record results
  • ☐ Speed test (Wi-Fi) — compare
  • ☐ Ping 8.8.8.8 — average RTT
  • ☐ Traceroute to target site — check slow hops
  • ☐ Inspect Task Manager / Activity Monitor for heavy apps
  • ☐ Reboot modem + router
  • ☐ Switch DNS to 1.1.1.1 or 8.8.8.8
  • ☐ Test with a VPN (diagnosis only)

What to tell your ISP (if you open a ticket)

Provide these facts — it speeds up resolution:

  • Time and date of the issue
  • Speed test results (Ethernet and Wi-Fi)
  • Ping/traceroute output (attach a text file)
  • Evidence of packet loss or repeated disconnects
  • Devices affected and whether the issue is constant or intermittent

Conclusion — short & useful

If speed tests show high Mbps but browsing or streaming feels slow, don’t blame the raw number alone. Investigate latency, Wi-Fi quality, local congestion, server limits, and background apps. A few simple checks (wired test, ping, traceroute, and removing background traffic) usually reveals the culprit.

Want more Tek Answers? This is Tek Answers #1. If you want, I can create short, copy-ready posts like this every week: practical diagnostics, fixes, and a one-page checklist readers can use immediately.

— TekonAir · Practical tech answers for people who want results, not buzzwords.