Fix Slow Deco Internet Speed: Setup, Testing, and Troubleshooting

Deco slow internet is a common frustration, but the cause is usually one of three things: unit placement, a device limitation, or a testing method that produces misleading results. This guide walks through each factor in order so you can isolate exactly where the slowdown is happening and address it directly.

Key Takeaways

• Deco units should be placed in open spaces, not inside closets, TV cabinets, or other enclosed areas, as those locations reduce signal strength and Internet speeds.
• When testing speeds over a wired connection, confirm that both the Ethernet cable and the PC support 1 Gbps (Gigabit). A 100 Mbps Ethernet port will cap your results regardless of your Internet plan.
• For wireless speed tests, disconnect all other wireless devices first. Multiple devices sharing the network at the same time will bring down individual test results.
• Reconnect to Wi-Fi on your phone or laptop before each speed test. Some devices connect to the wrong Deco node and show lower speeds as a result.
• The speed test in the Deco app (Deco > Network > Test Internet Speed) measures only the main Deco unit's connection speed, not the speed that individual connected devices receive.
• If the main Deco's speed looks normal, but a satellite unit is running slower, a separate troubleshooting path applies. See the link in the troubleshooting section below.

Things to Check Before Testing Speed

Getting accurate results starts before you open a speed test app. Work through these points first:

• Place every Deco unit in an open space. Do not put them inside closets, TV cabinets, or any enclosed area.
• If using a wired PC to test speed, confirm that all Ethernet cables and the PC itself support a 1 Gbps (Gigabit) connection.

Note: If your Ethernet port is marked as a 100 Mbps port, your speed results will not exceed 100 Mbps regardless of your plan. You can check your port rating in the specifications on the TP-Link website or on the product box. You can skip this check if your broadband plan is slower than 100 Mbps.

• If using a wireless device, confirm it supports 5 GHz and is capable of reaching higher speeds. Some older laptops have wireless network adapters that cannot reach high speeds even under ideal conditions.
• The speed test under Deco > Network > Test Internet Speed measures the maximum speed of the main Deco unit only. It does not represent the speed that all connected devices receive.
• The Deco Lab speed test, if available on your device, measures your phone's real-time speed. Results from this test should match results from the Ookla Speedtest app.

How to Test Your Speed Correctly

These steps are meant to be followed in order. Testing the ISP modem first gives you a baseline, and each step after that narrows down where any speed loss is occurring.

1. Connect a Gigabit-capable PC directly to your ISP modem and run a speed test using the Ookla Speedtest app or https://www.speedtest.net. This establishes your maximum available broadband speed.
2. Connect the same PC directly to the main Deco unit using an Ethernet cable and run the speed test again. Compare the result to your ISP modem baseline.
3. For wireless testing, disconnect every other wireless device from the network before running the test. Multiple devices on the network simultaneously will reduce results.

Important: Reconnect to Wi-Fi on your phone or laptop before each wireless speed test. Some devices do not support mesh roaming and may hold a connection to the wrong Deco node, which causes lower-than-expected results.

Troubleshooting Based on Your Results

Once you have your test results, use the path below that matches your situation.

If the main Deco unit is showing slow speeds: See Troubleshooting Slow Speed on the Main Deco.

If a satellite Deco unit is showing slower speeds than the main unit: See Slow Speed on Satellite Deco.

If you still believe your speeds are lower than expected after testing, contact TP-Link Support with the following details:

1. Your speed test results.
2. Your internet service provider (ISP) name.
3. The speed test servers used.
4. Your Deco network topology and the devices used for testing.

To gather your PC's network adapter information to share with support (Windows only), follow these steps. Note that this data helps the support team diagnose network adapter-related issues more quickly.

1. Press Win+R on your keyboard, type "cmd," and press Enter. A small black console window will open.
2. In the console, type "ipconfig /all" and press Enter. Your network adapter details will appear in the window.
3. Copy the full contents of the console window and include it when you contact support.