Packet loss on home Wi-Fi: causes and fixes

Your data travels in small packets. Most arrive; a few may not. When enough go missing, you feel it: a voice that turns metallic, a game where opponents jump around, a video call that briefly becomes a mosaic, a page that hangs and then loads all at once.

What packet loss is, and why Wi-Fi hides some of it

Wi-Fi expects trouble. When a packet doesn't make it across the air, the radios quietly send it again, sometimes several times. So on Wi-Fi, loss usually shows up first as delay and jitter, because of all those retries. See latency and jitter explained.

Only when the retries also fail do packets go missing for good, and that's the loss your apps notice.

Common causes at home

• The edge of coverage. Far from the router, more packets fail and need retries, and eventually some give up. The classic cause.
• Interference. Neighbors' networks, microwaves, older cordless devices on 2.4 GHz.
• A struggling extender or wireless node, whose own link to the router is weak. Every packet crosses two weak hops.
• Devices clinging to the wrong access point as you move around. See phone won't switch to the nearest node.
• Noisy powerline links, which lose packets when appliances switch on. See powerline.
• An overloaded line or router, when a big upload or download fills the queue.

How to track it down

1. Test near the router, then in the problem room. Loss only in the far room points to coverage. Loss everywhere points to the line or the router.
2. Test over several minutes, not seconds. Loss often comes in bursts.
3. Test at different times. If it appears in the evening only, suspect crowding; if it appears when the washing machine runs, suspect powerline.
4. Watch what happens while walking. Loss while moving, and not while sitting, points to roaming between units.

Fixes by cause

• Coverage: move the router, or add a node or wired access point closer to the problem area. See where to put a mesh node.
• Interference: use 5 GHz where possible; see 2.4 GHz vs 5 GHz by room.
• Wireless hops: wire the node, even with powerline or coax.
• The device: for calls and games, a cable to the most important device removes Wi-Fi loss entirely. See Wi-Fi for a game console and video calls freezing.

See where the loss lives

WiFi Heatmap counts unanswered requests in each spot you measure and shows them alongside response time and its variation. Map the home once and the rooms where packets go missing stand out, which tells you exactly where coverage needs to improve.