Netflix is buffering. Your video call keeps freezing. Pages take forever to load. Before you call your ISP and spend 45 minutes on hold, let's figure out what's really going on — and whether the problem is your internet, your WiFi, or something else entirely.

The three things that matter¶

When people say "my internet is slow," the problem is usually one of three things:

graph LR
    Device["Your Device"] -->|"WiFi Signal"| Router["Router"]
    Router -->|"Your Connection"| ISP["ISP"]
    ISP -->|"The Internet"| Server["Website/Service"]

    style Device fill:#4a90d9,color:#fff
    style Router fill:#f5a623,color:#fff
    style ISP fill:#7b68ee,color:#fff
    style Server fill:#4caf50,color:#fff

1. Speed — How much data can flow through per second (like the width of a pipe)
2. Latency — How long it takes data to make a round trip (like the length of the pipe)
3. Stability — Whether the connection stays consistent or fluctuates (like water pressure)

A connection can be fast but laggy (high speed, high latency — fine for downloads, bad for video calls). Or it can be responsive but slow (low speed, low latency — fine for browsing, bad for streaming). Let's measure all three.

Step 1: Test your speed¶

netglance speed

Speed Test Results
──────────────────────────────────────────────────
Download:    87.3 Mbps
Upload:      11.2 Mbps
Latency:     14 ms
Server:      Speedtest.net (Sydney)

How to read this:

What different speeds actually feel like:

• 5 Mbps — one person can stream standard-def video
• 25 Mbps — one person can stream 4K, or a small household can browse comfortably
• 100 Mbps — a household can stream, game, and video call simultaneously
• 500+ Mbps — you'll never notice speed as a bottleneck

Step 2: Check latency and jitter¶

Speed isn't everything. For video calls and gaming, latency and stability matter more:

netglance ping 8.8.8.8

Ping Results — 8.8.8.8 (Google DNS)
──────────────────────────────────────────────────
Packets:     20 sent, 20 received, 0% loss
Latency:     min 12ms, avg 15ms, max 23ms
Jitter:      3.2 ms

What the numbers mean:

• Latency (avg) — the time for a round trip. Under 50ms is good for most things. Under 20ms is great for gaming.
• Jitter — how much the latency varies. Under 5ms is stable. Over 20ms means choppy video calls.
• Packet loss — data that never arrived. Even 1% loss causes noticeable problems. 0% is what you want.

Step 3: Test for bufferbloat¶

Bufferbloat is a sneaky problem: your connection seems fast on a speed test, but feels terrible when multiple people use it at once. It happens when your router's buffers are too large, causing huge latency spikes under load.

netglance perf --bufferbloat

Bufferbloat Test
──────────────────────────────────────────────────
Idle latency:        15 ms
Latency under load:  340 ms    ← this is the problem
Bufferbloat grade:   F

What the grades mean:

• A (under 5ms increase) — excellent, no bufferbloat
• B (5-30ms increase) — minor, barely noticeable
• C (30-60ms increase) — moderate, may notice during heavy use
• D-F (60ms+ increase) — severe, video calls drop during downloads

Step 4: Trace the route¶

If things are slow, find out where the bottleneck is:

netglance route 8.8.8.8

Traceroute to 8.8.8.8
──────────────────────────────────────────────────
 1  192.168.1.1      1 ms    ← your router
 2  10.0.0.1         8 ms    ← ISP local
 3  172.16.50.1     15 ms    ← ISP regional
 4  72.14.236.1     14 ms    ← Google edge
 5  8.8.8.8         15 ms    ← destination

What to look for:

• Big jump at hop 1 — problem is your WiFi or router
• Big jump at hop 2-3 — problem is your ISP's local infrastructure
• Big jump mid-path — congestion somewhere in the internet backbone
• Steady increase — normal, distance takes time

graph LR
    You["You<br/>0 ms"] -->|"1 ms"| Router["Router"]
    Router -->|"+7 ms"| ISP["ISP"]
    ISP -->|"+7 ms"| Regional["ISP Regional"]
    Regional -->|"+90 ms !"| Backbone["Backbone"]
    Backbone -->|"+5 ms"| Dest["Destination"]

    style Backbone fill:#ff6b6b,color:#fff

In this example, the big jump at the backbone means congestion outside your control — but at least you know it's not your home network.

Step 5: Check if it's your WiFi¶

Sometimes the internet is fine but WiFi is the bottleneck. Test from a wired connection vs WiFi:

# Check WiFi signal and channel congestion
netglance wifi

WiFi Environment
──────────────────────────────────────────────────
Your network:    MyHomeWiFi
Signal:          -68 dBm (fair)
Channel:         6 (congested — 5 networks)
Frequency:       2.4 GHz

WiFi signal strength guide:

Common WiFi fixes:

1. Switch to 5 GHz — faster but shorter range. Great if you're in the same room.
2. Change your channel — if 5 other networks share your channel, switch to a less crowded one.
3. Move your router — central location, elevated, away from microwaves and thick walls.
4. Get a mesh system — if your home is large or has thick walls.

Diagnosing common problems¶

"Netflix buffers but speed test says 100 Mbps"¶

This is almost always bufferbloat or WiFi congestion. Run netglance perf --bufferbloat and check your WiFi signal.

"Video calls keep freezing"¶

Check jitter with netglance ping. Video calls need low, stable latency — they're more sensitive to jitter than raw speed. Also check if someone else is downloading.

"It's slow at certain times of day"¶

Run netglance speed at different times. If it's consistently slow from 7-10 PM, your ISP is likely congested. This is common with cable internet.

"One device is slow, others are fine"¶

The problem is that device's WiFi connection, not your internet. Check netglance wifi from that device, or move it closer to the router.

"Everything was fine until recently"¶

Run netglance baseline diff to see what changed. A new device might be hogging bandwidth, or your ISP may have changed something.

Quick reference¶

Next steps¶

• Keep My Network Healthy — set up continuous speed and latency monitoring so you can track trends and catch problems early
• What's on My Network? — find the device that's hogging all the bandwidth