Reddit Video & Image Downloader

Reddit adopted DASH — Dynamic Adaptive Streaming over HTTP — for video hosting. Under DASH a single video is stored as a set of separate files: several video renditions at different resolutions, and one audio track, all described by a manifest. The player picks a video rendition based on your connection and plays it alongside the audio file. Nothing on Reddit's servers is a complete, self-contained video.

That architecture is the entire reason Reddit videos so often end up silent. When you right-click and save, or point a generic downloader at a v.redd.it link, you get one file — the video rendition. The audio lives at a different URL entirely and is never fetched. The result plays perfectly and has no sound, which is confusing enough that it is one of the most-searched Reddit problems.

Merging the two back together is called muxing. It is not re-encoding: the video and audio streams are copied into a single MP4 container without being decoded, so there is no quality loss and no waiting for a re-render. The output is an ordinary MP4 that plays anywhere.

Reddit also hosts still images on i.redd.it, animated content as either GIF or silent MP4, and galleries that hold up to twenty images under one post URL. Crossposts add a wrinkle — the media lives on the original post, not the crosspost, so the link has to be followed back to its source before anything can be fetched.