Internet & modems

Download speed is fast but upload speed is very slow

Many home internet plans, especially cable, are designed with much faster download than upload speeds, so a big gap is often normal, but unusually slow uploads relative to your plan can affect video calls and cloud backups and are worth checking.

Difficulty
Easy
Time
15–20 minutes
DIY cost
$0
Pro cost
$0

Symptoms

  • Speed test shows download much faster than upload, more than the plan's advertised ratio
  • Video calls freeze or have poor quality specifically when talking or sharing your screen
  • Uploading files or backing up to the cloud takes a long time
  • Streaming and downloading work fine while sending large files is slow

Likely causes

  • CommonInternet plan naturally has asymmetric speeds (common with cable internet)Cable and DSL plans often provide much higher download than upload speed by design, since typical home usage is download-heavy.
  • PossibleUpload speed below what your plan promises due to a line or equipment issueIf your upload speed is far below even your plan's normal (lower) upload rating, something else may be wrong.
  • PossibleMultiple devices uploading simultaneously (backups, cloud sync)Background cloud backup or sync processes can consume most of the limited upload bandwidth without you noticing.
  • Less commonRouter prioritizing download traffic over uploadSome router QoS misconfigurations can disproportionately favor download traffic.

What to do

  1. Check your specific plan's advertised upload speed (not just download), since these are often listed separately and upload is typically much lower.
  2. Run a wired speed test and compare the upload result specifically to your plan's promised upload speed, not to the download number.
  3. Check for background upload activity like cloud backup services (Google Photos, iCloud, Dropbox) running on any device and pause them during important calls.
  4. Restart the router and modem, then retest.
  5. If your upload speed is significantly below your plan's own advertised upload rate (not just lower than download), treat it like any other slow-speed issue and contact your ISP.
  6. For frequent video calls or large uploads, consider whether a fiber plan (which typically offers symmetrical speeds) is available in your area as a longer-term solution.
  7. Check the router's QoS settings for any rule that might be deprioritizing upload traffic and adjust or disable it if found.

Tools and parts

  • Speed test app or website

When to call a pro

If a fiber connection is available in your area and video calls or uploads are a regular need, ask your ISP about symmetrical-speed fiber plans as an upgrade.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.