aria2

.aria2Aria2 Download File

Aria2 Project · 2009

Developer
Aria2 Project
Category
System Files
MIME Type
application/x-aria2
First Released
2009
Open Format
Yes
File Signature
Starts with '# # aria2 #
At a Glance
.aria2
Aria2 Download File

.aria2 files are control files for the Aria2 download manager that save the state of an unfinished download to allow resuming.

Reviewed on July 1, 2026
Compression
Plain text
Transparency
N/A
Editability
Medium
Best for
Download resume management

Key Features

  • Saves download progress for later resumption.
  • Stores metadata like URL, file size, and downloaded parts.
  • Enables pausing and resuming multi-source downloads.
  • Text-based format, human-readable to some extent.

Best For

  • Users who frequently download large files.
  • Situations where internet connections are unstable.
  • Automated download scripts that need to be robust.
  • Anyone wanting to manage downloads efficiently.

Less Ideal For

  • Storing actual file content.
  • Opening in standard media players or document viewers.
  • Using as a general backup file.
  • Sharing with users not using Aria2.

Common Use Cases

  • Pausing and resuming large file downloads.
  • Saving download state before shutting down or losing internet.
  • Managing multiple simultaneous downloads with resume capability.
  • Ensuring download integrity by tracking progress.

How to Open It

  1. The .aria2 file is automatically used by the Aria2 application when resuming a download. You don't typically 'open' it directly.
  2. If you have a paused download, simply start Aria2 and it should recognize the associated .aria2 file in the same directory to continue the download.
  3. You can manually point Aria2 to an .aria2 file if it's not automatically detected, using specific command-line options or interface commands.
  4. For advanced users, the file can be inspected with a text editor to understand its contents.

What is a .aria2 file?

An .aria2 file is not a media file or a document you can directly open and view. Instead, it's a control file used by the Aria2 download manager. When you pause a download managed by Aria2, it saves the current state, including which parts of the file are already downloaded and where to resume, into an .aria2 file. This allows you to close your computer or interrupt the download and then restart it later from the exact point it left off. It's essentially a resume token for your downloads.

Programs That Open .aria2 Files

PlatformProgram
WindowsAria2FreeOfficial
macOSAria2FreeOfficial
LinuxAria2FreeOfficial
AndroidAria2 (via Termux or other interfaces)Free
Web BrowserWeb UIs for Aria2 (e.g., AriaNG, AriaUI)Free

Common Problems with .aria2 Files

⚠️ Aria2 won't resume the download.
Ensure the .aria2 file is in the same directory as the partially downloaded file and that Aria2 is configured to look in that location. Check for errors in the Aria2 logs.
⚠️ Missing .aria2 file after closing Aria2.
Aria2 might not have had time to save the state, or it was configured to not save temporary state. Check Aria2's configuration for auto-save settings.

Frequently Asked Questions

Can I open an .aria2 file to see the downloaded content?

No, an .aria2 file is a control file that stores download progress and metadata, not the actual file content. You can open it with a text editor to view technical details, but it's not human-readable content.

What happens if I delete the .aria2 file?

If you delete the .aria2 file, Aria2 will lose the record of the download's progress, and you will likely have to restart the download from the beginning.

Is the .aria2 file the actual file I was downloading?

No, it's a separate metadata file created by Aria2 to manage the download process. The actual downloaded content will be in a file with the intended extension (e.g., .zip, .mp4).

Technical Details

The .aria2 file is a text-based file that stores metadata about the download, such as the URL, the total file size, and the downloaded portion. It also contains information about the different connections and pieces of the file that have been acquired. This structured data allows Aria2 to efficiently pick up where it left off without re-downloading already completed segments.

Did You Know?

Aria2 is a lightweight, multi-protocol & multi-source command-line download utility.
The .aria2 file format is designed to be simple and efficient for resuming downloads across various network conditions.

Security Information

.aria2 files themselves are generally safe as they only contain download management information. However, always ensure you are downloading files from trusted sources and using a reputable download manager like Aria2 to avoid malware embedded within the actual downloaded content.