Testing your Xfinity connection
Xfinity, Comcast's internet brand, mostly runs over a cable (DOCSIS) network, with fibre in selected neighbourhoods. Download speeds are high, but on most cable tiers the upload is a fraction of the download, which matters for video calls, cloud backups and streaming yourself.
This test detects your provider automatically and measures download, upload, ping, jitter and latency under load against the nearest server on Cloudflare's network. Enter your plan speed under the result to see the percentage you really get.
Xfinity speeds by plan
| Plan | Download | Upload |
|---|---|---|
| 300 Mbps | about 300 Mbps | lower than download (varies by area) |
| 500 Mbps | about 500 Mbps | lower than download |
| 1 Gig | about 1,000 Mbps | lower than download |
| 2 Gig | about 2,000 Mbps | lower than download |
| Fiber tiers (select areas) | up to 10 Gbps | can be symmetrical |
Xfinity's national lineup in 2026 runs from 300 Mbps to 2 Gig in most areas. Upgraded markets and fibre-fed addresses can get faster or symmetrical tiers. Your exact upload speed is printed on your plan's broadband label. Checked on 31 October 2026; tiers change and vary by address, so confirm on the Xfinity website.
What result should you expect?
On a 1 Gig plan, a wired test from a computer with a gigabit port usually shows 900 to 940 Mbps (the limit of the port), and slightly more on multi-gig ports. Over Wi-Fi, 300 to 700 Mbps is common. Compare the upload with the figure on your broadband label, not with the download.
Measure your connection now. Start the test
Common reasons for slow Xfinity speeds
- Old modem: if you use your own modem, gig tiers need a DOCSIS 3.1 model; an older DOCSIS 3.0 modem caps your speed.
- Evening slowdowns: the cable segment is shared by the neighbourhood. If speed drops at the same hours every day, read why internet slows down in the evening.
- Wi-Fi from the gateway: test next to the gateway, then in the room where you use the internet, with our Wi-Fi or line diagnosis.
- Data usage: some older plans had a monthly data allowance. Check the terms of your plan if speeds change after heavy use.
Before contacting Xfinity support
- Restart the gateway from the Xfinity app or by unplugging it for 30 seconds.
- Run three tests over Ethernet at different hours and keep screenshots.
- Check the outage map in the Xfinity app before calling.
- If speeds stay below your plan, check for traffic throttling, then contact support with your saved results.
More help: slow internet: causes and fixes and all providers we cover.
Sources
SpeedFibre is an independent website, not affiliated with Xfinity. The provider's name is used only to describe the service being tested.
Frequently asked questions
Why is my Xfinity upload so much slower than my download?
Cable networks reserve most of their capacity for the downstream direction, so most cable tiers have a much lower upload. Only fibre-fed or upgraded symmetrical tiers have equal upload and download.
Is the speed test in the Xfinity app different from this one?
The app can test speed to the gateway, which ignores your Wi-Fi. Our test measures what reaches the device you are holding, through Wi-Fi or cable, against the nearest Cloudflare server.
Why does my 1 Gig plan show 940 Mbps?
That is the practical maximum of a gigabit Ethernet port. To see more, you need a device and cable that support 2.5 Gbps or faster.
