What Is Progressive Download?

Progressive download is a technique used to stream media from a web server to a client such as a video player on a laptop or mobile phone.

Without progressive download, a client has to download the entire media file before video playback can start. Media files are typically large, so users must wait a significant time before they can watch the video, resulting in a disappointing user experience. With progressive download, only a small part of the video file has to be dowloaded before playback begins. (Even with progressive download, low bandwidth can make the download lag behind the rate of play, in which case playback pauses until enough material is downloaded for viewing to continue.)

Progressive download is possible because at the start of the download the media server sends metadata about the video file to the video player. The metadata functions like a table of contents, enabling playback to begin without all the data being available.

Pseudo‑streaming is a related technology that enables users to jump to different points in the video (called seeking), including sections for which the data has not yet been downloaded.

How Can NGINX Plus Help?

NGINX Plus and NGINX are the best-in-class load‑balancing solutions used by high‑traffic websites such as Dropbox, Netflix, and Zynga. More than 350 million websites worldwide rely on NGINX Plus and NGINX Open Source to deliver their content quickly, reliably, and securely.

NGINX Plus provides an all-in-one streaming media platform designed specifically to load videos quickly and reliably regardless of volume. It supports these important features:

  • Progressive download, pseudo‑streaming, and adaptive streaming, so all users enjoy fast and reliable video playback on any device
  • Seamless support for popular video coding formats from Apple and Adobe