Why are there different video formats?
The web video landscape has three dominant delivery methods. Each was designed to solve different problems. Understanding them helps you know why some videos are easy to download and others are not, and what TimeSave does behind the scenes to handle each type.
HLS
HTTP Live Streaming
Developed by Apple in 2009. The most widely used streaming protocol on the internet today. Delivers video as a sequence of small .ts segment files listed in an .m3u8 playlist. Supported natively in Safari, and via Media Source Extensions in Chrome and Firefox.
DASH
Dynamic Adaptive Streaming
An international standard from the MPEG group, also known as MPEG-DASH. Works similarly to HLS but uses an .mpd XML manifest file and typically delivers segments in fragmented MP4 format rather than .ts. YouTube uses DASH for most of its streams.
MP4
Direct File
A single, complete video file delivered via a plain URL. The simplest format — the browser downloads and plays it directly. Common for self-hosted videos, news clips, and any site not using adaptive streaming.
Key technical differences
| Feature | HLS | DASH | MP4 |
|---|
| Playlist/Manifest | .m3u8 | .mpd (XML) | None |
| Segment format | .ts (MPEG-TS) | fMP4 or .ts | Single file |
| Adaptive bitrate | ✅ Yes | ✅ Yes | ❌ No |
| DRM support | FairPlay | Widevine / PlayReady | Varies |
| TimeSave support | Full (in-browser MP4) | ffmpeg command | Full (direct download) |
Adaptive bitrate streaming explained
Both HLS and DASH support adaptive bitrate (ABR) streaming. This means the server offers the same video at multiple quality levels (e.g., 1080p, 720p, 480p, 360p). The player monitors your network speed and switches to a higher or lower quality stream automatically, mid-playback, to prevent buffering. That is why streaming video rarely pauses even on a slow connection — it just drops to a lower quality.
The master playlist (or master manifest) lists all available quality variants. TimeSave reads this master playlist and selects the highest-quality stream for download.
What about DRM-protected streams?
Digital Rights Management (DRM) adds an additional encryption layer on top of HLS or DASH. The video segments are encrypted with a key that only licensed players can obtain. TimeSave does not bypass DRM — it works only with unprotected streams. This means it cannot download content from Netflix, Disney+, Amazon Prime Video, or other major subscription services that use DRM.
How to identify which format a video uses
- Open Chrome DevTools (F12) and go to the Network tab.
- Filter by "Media" or search for ".m3u8" or ".mpd".
- Press Play on the video. If you see .m3u8 requests, it is HLS. If you see .mpd requests, it is DASH. If you see a direct .mp4 URL, it is a plain file.
- Alternatively, simply install TimeSave — it automatically identifies and labels each detected video as HLS, DASH, or MP4.