What Determines Your Internet Speed?

Several things stack between you and the speed you experience — and only some of them belong to your ISP.

• Your plan is the ceiling — nothing goes faster than what you subscribed to
• The medium — fiber and wireless have different stability characteristics
• In-building WiFi — the most common bottleneck of all
• Device age and cabling — old hardware tops out early
• The far end — the server you're talking to is outside any ISP's control
• Congestion — shared packages flex under load in ways dedicated circuits do not

For the details, see understanding speed test results and shared vs dedicated speed.