What is a .torrent file?
BitTorrent Metadata File · Data · Bram Cohen / BitTorrent · 2001
A .torrent file is a small metadata file, not the content itself. It tells a BitTorrent client which files to download, their sizes and checksums, and where to find peers. You open it in a torrent client, which then fetches the actual data.
What is a .torrent file used for?
The .torrent holds only a description of a download: the list of files, a hash of each piece so the data can be verified, and tracker (announce) URLs that help find other people sharing it.
That is why a .torrent is tiny even when the download is huge, the real data lives on the peer-to-peer network, not in the file.
You open one in a BitTorrent client such as qBittorrent or Transmission, which reads the metadata and starts downloading. Magnet links do the same job without a separate file.
Using BitTorrent is perfectly legal; whether a particular download is depends entirely on the content and your rights to it.
How to open a .torrent file
The .torrent format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- qBittorrent
- Transmission
macOS
- Transmission
- qBittorrent
Linux
- Transmission
- qBittorrent
Web
- Not applicable
How to convert a .torrent file
You can convert a .torrent file to Not convertible using a conversion tool or the export menu of an app that opens it.
.torrent file signature (magic bytes)
Programs recognise a .torrent file by the bytes at the start of the file, not by its name. These are the signatures for Torrent. For a full breakdown, see the Torrent file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 64 38 3A 61 6E 6E 6F 75 6E 63 65 | 0 | 'd8:announce' (bencoded dictionary; common but not guaranteed) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .torrent file?
A .torrent file is a small metadata file, not the content itself. It tells a BitTorrent client which files to download, their sizes and checksums, and where to find peers. You open it in a torrent client, which then fetches the actual data.
How do I open a .torrent file?
Open it in a BitTorrent client such as qBittorrent or Transmission. The client reads the file's metadata and downloads the actual content from other peers.
Is opening a .torrent file safe?
The .torrent itself is just a small text-like description and is safe to open in a client. The care is in what you then download: only fetch content you are allowed to, and scan the finished files.
Related formats
Sources
Details on this page were checked against authoritative references: