How do I prove my internet is slow at night?

Run a speed test at the same time each evening and again at midday, over an Ethernet cable, for a week or two. A dated record of results is far more persuasive than a single screenshot.

Why is my internet slow at night?

Q: Why is my internet slow at night?

Because everyone else is online too. Cable connections share capacity between neighbouring homes, so when the whole street streams at once, each home gets less. Providers also see peak demand between roughly 7pm and 11pm, and links that are comfortable at midday become congested.

Q: Is evening slowdown my provider's fault?

Partly. Some contention is unavoidable, but severe slowdowns mean the provider has oversold capacity in your area. If your evening speed is consistently under half your midday speed, that is worth raising with them, with dated evidence.

Updated 14 July 2026

Short answer. Because your neighbours are online too. Cable broadband shares capacity between nearby homes, so when the whole street streams at 9pm, everyone gets a smaller slice. This is called contention, and it is normal — up to a point. If your evening speed is consistently less than half your midday speed, your provider has oversold your area, and that is worth complaining about.

What is actually happening

Cable broadband is not a private wire from your home to the internet. It is a shared pipe running down your street, split among the houses on it. At 11am, most of that pipe is yours. At 9pm, when every home is streaming, you are all drawing from the same pool.

Fibre-to-the-home suffers far less from this. DSL sits somewhere in between. If your evening collapse is severe, your connection type is a large part of the explanation.

Rule out your own house first

Before blaming the provider, eliminate the causes inside your walls — because those are the ones you can actually fix:

Wi-Fi congestion. Evening is when every router on your street is busiest, and they all interfere with each other. Test over Ethernet to take Wi-Fi out of the equation entirely.
Your own devices. Backups, updates and downloads often schedule themselves for the evening.
A tired router. Many routers degrade after weeks of uptime. Restart it.

How to build a case

A single slow result proves nothing, and your provider knows it. What is persuasive is a pattern.

Test over an Ethernet cable, so the result is about the line and not your Wi-Fi.
Test at the same two times each day — say midday and 9pm.
Do it for at least a week.
Take the record to your provider, and point at the gap.

Speed of Bits keeps your last twenty results in your own browser precisely so you can do this without an account and without anyone storing your data.

Start building your record →

Common questions

Is evening slowdown my provider's fault?

Partly. Some contention is unavoidable. But a consistent drop to under half your midday speed means capacity has been oversold in your area, and that is a legitimate complaint.

Does a better router fix it?

Only if the bottleneck is inside your home. A new router cannot create capacity on a congested street-level link.

Does a VPN help?

Almost never. A VPN adds a hop and usually makes both speed and ping worse. It only helps in the narrow case where a provider is deliberately throttling a specific service.