---
obj: application
os:
  - linux
website: https://aria2.github.io/
repo: https://github.com/aria2/aria2
---
# aria2
[aria2](https://aria2.github.io/) is a utility for downloading files. The supported protocols are [HTTP](../../internet/HTTP.md)(S), [FTP](../../internet/FTP.md), SFTP, [BitTorrent](../../tools/BitTorrent.md), and Metalink. aria2 can download a file from multiple sources/protocols and tries to utilize your maximum download bandwidth. It supports downloading a file from [HTTP](../../internet/HTTP.md)(S)/[FTP](../../internet/FTP.md)/SFTP and [BitTorrent](../../tools/BitTorrent.md) at the same time, while the data downloaded from [HTTP](../../internet/HTTP.md)(S)/[FTP](../../internet/FTP.md)/SFTP is uploaded to the [BitTorrent](../../tools/BitTorrent.md) swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like [BitTorrent](../../tools/BitTorrent.md). Aria2 can be used as a downloader by [yt-dlp](../media/yt-dlp.md).

## Usage

```shell
aria2c [<OPTIONS>] [<URI>|<MAGNET>|<TORRENT_FILE>|<METALINK_FILE>]
```

### Options
| Option                                       | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| -------------------------------------------- |   |
| `-d, --dir=<DIR>`                            | The directory to store the downloaded file.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| `-i, --input-file=<FILE>`                    | Downloads the URIs listed in **FILE**.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| `-l, --log=<LOG>`                            | The file name of the log file. If - is specified, log is written to stdout. If empty string("") is specified, or this option is omitted, no log is written to disk at all.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| `-j, --max-concurrent-downloads=<N>`         | Set the maximum number of parallel downloads for every queue item.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| `-V, --check-integrity [true/false]`         | Check file integrity by validating piece hashes or a hash of entire file.  This option has effect only in [BitTorrent](../../tools/BitTorrent.md), Metalink downloads with checksums or [HTTP](../../internet/HTTP.md)(S)/[FTP](../../internet/FTP.md) downloads with --checksum option.  If piece hashes are provided, this option can detect damaged portions of a file and re-download them.  If a hash of entire file is provided, hash check is only done when file has been already download. This is determined by file length. If hash check fails, file is re-downloaded from scratch.  If both piece hashes and a hash of entire file are provided, only piece hashes are used. Default: false |
| `-c, --continue [true/false]`                | Continue downloading a partially downloaded file.  Use this option to resume a download started by a web browser or another program which downloads files sequentially from the beginning.  Currently this option is only applicable to [HTTP](../../internet/HTTP.md)(S)/[FTP](../../internet/FTP.md) downloads.                                                                                                                                                                                                                                                                                                                                                                                        |
| `--checksum=<TYPE>=<DIGEST>`                 | Set checksum. TYPE is hash type. The supported hash type is listed in Hash Algorithms in aria2c -v. DIGEST is hex digest.  For example, setting sha-1 digest looks like this: `sha-1=0192ba11326fe2298c8cb4de616f4d4140213838` This option applies only to [HTTP](../../internet/HTTP.md)(S)/[FTP](../../internet/FTP.md) downloads.                                                                                                                                                                                                                                                                                                                                                                     |
| `-x, --max-connection-per-server=<NUM>`      | The maximum number of connections to one server for each download.  Default: **1**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| `-k, --min-split-size=<SIZE>`                | aria2 does not split less than 2\*SIZE byte range.  For example, let's consider downloading 20MiB file. If SIZE is 10M, aria2 can split file into 2 range (0-10MiB) and (10MiB-20MiB) and download it using 2 sources(if --split >= 2, of course).  If SIZE is 15M, since 2\*15M > 20MiB, aria2 does not split file and download it using 1 source.  You can append K or M (1K = 1024, 1M = 1024K).  Possible Values: 1M -1024M Default: 20M                                                                                                                                                                                                                                                             |
| `-o, --out=<FILE>`                           | The file name of the downloaded file. It is always relative to the directory given in `--dir` option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| `-s, --split=<N>`                            | Download a file using N connections.  If more than N URIs are given, first N URIs are used and remaining URIs are used for backup.  If less than N URIs are given, those URIs are used more than once so that N connections total are made simultaneously.  The number of connections to the same host is restricted by the `--max-connection-per-server` option.  See also the `--min-split-size` option.  Default: 5                                                                                                                                                                                                                                                                                   |
| `-t, --timeout=<SEC>`                        | Set timeout in seconds. Default: 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `--check-certificate [true/false]`           | Verify the peer using certificates specified in `--ca-certificate` option.  Default: true                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| `--http-user=<USER>, --http-passwd=<PASSWD>` | Credentials for [HTTP](../../internet/HTTP.md) Auth                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| `--header=<HEADER>`                          | Append HEADER to [HTTP](../../internet/HTTP.md) request header.  You can use this option repeatedly to specify more than one header:<br>`aria2c --header="X-A: b78" --header="X-B: 9J1" "http://host/file"`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| `--load-cookies=<FILE>`                      | Load Cookies from FILE using the Firefox3 format (SQLite3), Chromium/Google Chrome (SQLite3) and the Mozilla/[Firefox](../network/browsers/Firefox.md)(1.x/2.x)/Netscape format.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| `--save-cookies=<FILE>`                      | Save Cookies to FILE in Mozilla/[Firefox](../network/browsers/Firefox.md)(1.x/2.x)/ Netscape format. If FILE already exists, it is overwritten. Session Cookies are also saved and their expiry values are treated as 0.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| `-U, --user-agent=<USER_AGENT>`              | Set user agent for [HTTP](../../internet/HTTP.md)(S) downloads.  Default: `aria2/$VERSION`, $VERSION is replaced by package version.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| `-S, --show-files [true/false]`              | Print file listing of ".torrent", ".meta4" and ".metalink" file and exit.  In case of ".torrent" file, additional information (infohash, piece length, etc) is also printed.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| `--select-file=<INDEX>...`                   | (Torrent) Set file to download by specifying its index.  You can find the file index using the `--show-files` option.  Multiple indexes can be specified by using `,`, for example: `3,6`. You can also use `-` to specify a range: `1-5`. `,` and `-` can be used together: `1-5,8,9`.                                                                                                                                                                                                                                                                                                                                                                                                                  |
