FAQ
Frequently asked questions about aMule, covering general usage, the eD2k and Kademlia networks, and running aMule remotely. Use the table of contents to jump to a topic.
General
About aMule
Which distribution or OS is recommended for running aMule?
aMule runs on Windows, macOS, Linux, FreeBSD, and OpenBSD. Any modern Linux distribution with up-to-date packages works well. The best choice is whichever OS you are already comfortable maintaining. See Installation for the available packages and methods on each platform.
Getting started
I just installed aMule for the first time. How do I set it up?
The Quick Start guide walks through first-run setup step by step: nickname and language, bandwidth limits, Temp/Incoming directories, choosing what to share, and connecting and searching. For optimal download speeds, also read What are the best settings for a nice download rate?
For more help, ask on GitHub Discussions — the project's community forum and the best place to get answers. The legacy aMule forums and the #aMule channel on irc.libera.chat are still around, but most activity has moved to GitHub.
Interface: colors, icons and numbers
What do those colors in the progress bar mean?
These colours follow the eMule convention. See also GUI → File Details for the transfer view, and Searches → Result Row Colours for the search-results colours.
Downloading transfers list
| Color | Meaning |
|---|---|
| Red | No sources for this chunk in the current session |
| Blue (lighter → darker) | At least one source available; darker = more sources |
| Yellow | Currently being downloaded |
| Black | Already downloaded and verified |
| Green (full bar) | Download complete and verified; file is in your Incoming folder |
Expanded transfers list (double-click a transfer)
| Color | Meaning |
|---|---|
| Black | A chunk that source has and you don't |
| White | A chunk that source doesn't have |
| Green | A chunk both you and that source have |
| Yellow | A chunk that source is currently uploading to you |
Uploading transfers list
| Color | Meaning |
|---|---|
| Black | Chunks that client has completed and verified |
| Grey | Chunks that client doesn't have |
Note: not all clients report which parts they have completed, so some may show no bar at all.
Search results window
| Color | Meaning |
|---|---|
| Black | Only one client has this file |
| Blue (lighter → darker) | Two or more clients; darker = more clients |
| Red | File is already in your download queue |
| Green | You already have this file completely downloaded and shared |
What are all these icons?
See the "Icons and what they signify" section in the Getting Started guide.
What do those numbers in brackets in the sources column of the search window mean?
Those are the clients known to have the complete file. Even if the number in brackets is 0, it does not mean that no one has the complete file — it only means that no client has marked the shared file as "completed" (many clients do not do so). It is a rough indicator, not a definitive count. See Searches and What is a source?.
What do all those numbers in the sources column in the Downloads window mean?
The format is XX/YY + ZZ (WW) where:
| Value | Meaning |
|---|---|
XX | Number of available sources (sources you can currently download from) |
YY | Total number of sources found |
ZZ | Number of "Asked For Another File" (A4AF) sources |
WW | Number of sources from which you are currently downloading a chunk |
See What is A4AF? for the meaning of A4AF sources, and GUI → File Details for the full transfer view.
What do all those numbers in the priority column in the extended transfers window mean?
That is the queue position you have on that specific source for that file. Not all clients provide this information.
The number in brackets is how many positions you have moved in that client's upload queue:
- Negative (blue): positions you have gained since being added.
- Positive (red): positions you have lost since being added.
See What do the "QR: xxxx" numbers mean? and Concepts & Glossary — Queue Rank.
Why are there two transfer rates in the uploading transfer list?
When you are uploading a file to a client, the rate is shown as a single value in KBps. However, if that same client is also uploading to you simultaneously, the format changes to XX/YY:
| Value | Meaning |
|---|---|
XX | Speed at which you are uploading to that client |
YY | Speed at which that client is uploading to you |
This is especially useful for rare files: if you see a client uploading one of your rare files to you, you can assign that client a friend slot to upload to them faster, accumulate more credits on them, and consequently download faster from them.
What do the "QR: xxxx" numbers mean that I see when I look at my sources?
QR stands for Queue Rank — your current position in that source's upload queue. A lower value is better. If a source is an eMule client and there is no QR number, its queue is likely full and cannot accept more clients.
See Concepts & Glossary — Queue Rank and What is a source?.
Downloads and transfers
What is A4AF?
A4AF stands for Asked For Another File. It is a source-optimization mechanism.
When you download a file, aMule finds a list of clients sharing it. Some of those clients may also be sharing another file you are downloading, placing them in two separate download queues simultaneously. Since you cannot download two chunks from the same client at the same time, A4AF avoids this waste:
- Setting A4AF on a download tells aMule to find any source in that file's queue that is also in another file's queue and remove it from the other queue, concentrating sources on the current download.
- You can also set A4AF in reverse — donating sources from the current download to another — which is useful for lower-priority files in a series.
A source is only moved to another file when that other file is active — not stopped or paused, still missing parts the source can provide, and ready to download. A source that was just swapped is also held for a short period before it can be swapped again, to avoid bouncing it back and forth between files.
See What is a source? and eD2k Network — Credits and Scoring.
What is the difference between Transferred and Completed in the Downloads window?
- Transferred: the total amount of raw data received for the file. Data arrives in compressed form.
- Completed: the amount of useful, decompressed file data extracted from the received data — i.e., actual file content excluding protocol headers and compression overhead.
It is normal and expected for Transferred to be smaller than Completed. See GUI → File Details → Transfer for where these values are shown.
What is the difference between pausing and stopping a transfer?
| Action | Effect |
|---|---|
| Pause | All connections for that transfer are dropped, but the source list is kept. When resumed, aMule reconnects to those known sources. |
| Stop | The entire source list is discarded. When resumed, aMule starts searching for sources from scratch. |
See What is a source? for what the source list contains.
Why can't I preview a file?
aMule allows preview of video and audio files only. Two conditions must be met:
- The file has a recognized video or audio extension (video:
.avi,.mpg,.mpeg,.divx,.mov,.mkv, …; audio:.mp3,.ogg,.flac,.wav, …). See Searches → File Type for the full list of recognized extensions. - At least the first 256 KB of the file has been downloaded.
If aMule refuses to preview a file that you believe is previewable, navigate to your Temp directory manually and open the NNN.part file with a media player directly.
aMule slows down my computer whenever a download completes. Is this normal?
Yes. When a download completes, aMule performs a full file hash verification: it hashes all downloaded chunks and verifies them against the expected values. Even though chunk integrity is checked incrementally while downloading, this final pass ensures no chunk was corrupted by the user or an external application after it was written. This is CPU-intensive for large files and is expected behavior. See Concepts & Glossary — Chunks and Data Integrity and the part.met file format for how chunk hashing works.
Is there a way to open a text file and load all the ed2k links from it?
Yes. Create a plain text file with one ed2k:// link per line, name it ED2KLinks, and place it in ~/.aMule. aMule will automatically detect it, add all links to the download queue, and delete the file.
See ED2KLinks file for more information.
Sharing and files
Is there a way to recursively select a whole directory and its contents in Preferences?
Yes. In Preferences → Directories, right-click the directory in the Shared Directories tree to share it recursively, including all its subdirectories (double-click shares only that single directory). The full reference — the directory tree and its font/icon states, the rescan options, and the editable shareddir-explicit.dat / shareddir-recursive.dat files — is in Directories → Shared Directories.
What are all those files aMule creates the first time it is run?
Most of them are identical to eMule's. Detailed information about each file — and a complete list — can be found in aMule Files.
Where are my downloaded files?
See Directories for the default paths on each platform.
Can I use eMule's files and settings, and vice versa?
Most files can be shared between the two clients. The only files you cannot share are the program configuration files:
- eMule uses
preferences.ini - aMule uses
~/.aMule/amule.conf
All ED2K network-related files can be successfully shared by copying them between the two applications' directories. However, some files in ~/.aMule are aMule-specific (such as amulesig.dat or aMule.tmpl), so it is best to only move files that exist in both the aMule and eMule directories.
Moving half-downloaded files is straightforward: copy them from eMule's Temp directory (configurable in eMule's preferences; by default inside eMule's own folder on Windows) into aMule's Temp directory (see Directories for the path on your platform), and vice versa.
What is all that stuff in amulesig.dat and onlinesig.dat?
These files contain the current online signature — the current aMule status, if the signature feature is enabled. They are used by external statistics tools (CAS, wxCAS) to display your aMule activity.
amulesig.dat— aMule's own signature format.onlinesig.dat— compatibility with eMule's signature format.
How can I switch from eMule to aMule without losing my credits?
Credits are stored in a handful of .dat and .met files (starting with cryptkey.dat). Copying them from eMule's config directory into ~/.aMule preserves your credits. The Migrate from eMule to aMule guide lists every file and walks through the full process.
Credits, bandwidth and upload
How do I view a client's credits?
Right-click on the client's nickname and select Show Details. No specific credit value is shown directly, but you can see:
- The total amount of data that client has sent you (and that you have sent it).
- The Credits Modifier (shown as DL/UP Modifier in the dialog).
If the client is currently in your upload queue, the dialog also shows that client's rate and score as calculated by your aMule. See eD2k Network — Credits and Scoring for how the modifier is calculated.
I see messages about credits being lost in the log. Should I be worried?
No. Credits for a client are automatically deleted after approximately 150 days (~5 months) of not encountering that client. Additionally, credits may be removed for misbehaving clients. These are informational debug messages, not errors. See Concepts & Glossary — Credits for how the credit system works.
What are the best settings I can set to have a nice download rate?
The single most important factor is your upload limit: the eD2k protocol caps your download speed as a multiple of your upload speed until you reach 10 KBps, above which the cap is lifted. Set your upload limit to at least 10 KBps if your ISP allows it, and as high as you can afford. The more you upload, the more credits you accumulate, and the faster you download from other clients.
For the exact ratio table and a full configuration checklist, see Slow Download Speeds → Upload limit too low.
Tip for rare files: when you see a source uploading a chunk of that rare file to you, assign that client a friend slot so they get highest priority in your upload queue, building up credits faster.
Why can't I set aMule's download limit to more than X?
The ED2K protocol enforces a hardcoded upload/download ratio to prevent freeloading: your download limit is capped as a multiple of your upload limit until the upload reaches 10 KBps, above which there is no restriction. See Slow Download Speeds → Upload limit too low for the exact table.
I set Upload Limit to 0 KBps, but aMule is still transferring. What did I do wrong?
0 KBps means unlimited, not zero. There is no way to completely stop aMule from uploading — this is by design and identical behavior to all eD2k clients (eMule, eDonkey, etc.). Allowing users to completely disable uploads would destroy the eD2k network.
Even if you share no directories, aMule always shares the files you are currently downloading: every partial download is automatically shared so that its already completed chunks are available to other clients downloading the same file. (The Temp directory itself cannot be added as a shared directory — it is the part files inside it that are shared.) See Shared Files — What Files Are Shared.
What is slot allocation?
Each active upload connection is one slot. Slot allocation defines how much bandwidth is assigned to each slot.
Example: on a 10 Mbps line your upload limit is about 1,250 KBps. With the default slot allocation of 10 KBps aMule opens 1,250 / 10 = 125 upload slots, so up to 125 clients can download from you simultaneously, each averaging about 10 KBps. The slot count is always kept between 2 and 250, so on lines above ≈ 20 Mbps the 250-slot cap takes over unless you raise the slot allocation.
See Bandwidth & Upload Slots for how it works and recommended values, and Why is aMule ignoring the bandwidth I set per slot? for important caveats.
What is a friend slot?
A friend slot is a dedicated upload slot permanently reserved for a client in your Friends list. Only one friend can hold a slot at a time. When that friend (with the friend slot enabled) tries to download a file from you, they are given the highest priority in the upload queue and are always served from that dedicated slot.
While the friend is not downloading, the reserved slot reverts to the client with the highest score in your regular upload queue. See eD2k Network — Credits and Scoring for how upload priority and score are determined.
What is the real point of the download and upload graph scales in Preferences?
aMule only uses Bandwidth Limits (in the Connection tab) to control actual network usage. The Download graph scale and Upload graph scale (in the Statistics tab, formerly called Line Capacities) exist purely to give the Statistics graphs a meaningful scale.
Example: if you have a 100 KBps connection but your downloads never exceed 5 KBps (rare Indonesian free music), setting the graph scale to 100 KBps makes the graph show an almost flat line with no visual information. Setting it to 5–10 KBps makes the graph readable and useful.
See GUI → Statistics → Graphs and Preferences → Statistics.
Running aMule
Can I manage aMule remotely from a terminal?
Yes. Start an ssh session with the host running aMule, then use amulecmd to control it. To start new downloads, use the ed2k command. Remember that amulecmd must be configured with the EC password first.
Other options:
cas— shows basic aMule statistics on the command line.amuleweb— full web interface, if you can use a browser on the remote machine.
Is there any way to start aMule with no graphical interface?
Yes. Use amuled, the aMule daemon, which runs without any GUI and can run on a headless server. Control it with amuleweb, amulecmd, or amulegui. See Remote Access below for an overview.
Can I run two aMule instances at the same time?
Yes, though it is not recommended. aMule only checks if the current user is running another aMule instance. You can run additional instances as different user accounts:
xhost +
su - otheruser
amule &
Warning: aMule cannot detect instances running on a different X display for the same user. Running two instances of the same user account on different X displays will likely result in corrupted configuration and lost chunks.
For a clean way to run an additional headless instance, see amuled.
How can I get those nice aMule statistics some people post on IRC channels?
Use CAS (cas) or its graphical counterpart wxCAS (wxcas). Run cas in a terminal to get a text summary of your aMule status, or launch wxcas for a graphical display. See cas / wxcas for details.
Does aMule support Universal Plug and Play (UPnP)?
Yes, when compiled with UPnP support (via libupnp). UPnP lets aMule request port forwarding from your router automatically. It is enabled by default on every platform where libupnp is available — Windows, macOS, and Linux. See UPnP for configuration.
Can I have aMule receive data from standard input (for GDB or Valgrind)?
Yes, via the -i (--enable-stdin) parameter, which keeps standard input open instead of disabling it on startup. See Developer → Debugging.
Network and connectivity
eD2k and Kademlia
For a complete overview of both networks and their architecture, see:
- eD2k Network — architecture, High ID / Low ID, ports, limitations, credits and scoring
- Kademlia Network — serverless DHT, bootstrapping, firewalled status
- Concepts & Glossary — definitions of all technical terms (chunk, hash, credits, slots, queue…)
Why do the same files appear as different files in search results, even with the same name?
Because file identity is determined by the hash and size, not the name. Two files with identical names but different content have different hashes and appear as separate files. Two files with different names but identical content and size are treated as the same file. See eD2k Links — Why the filename is irrelevant.
Ports
aMule works even without any ports open, but you will receive a Low ID. For optimal operation (High ID) you must open the relevant ports for incoming connections — see Network Connectivity — Ports for the complete list and what each port is used for.
Why does Kademlia still say it is "firewalled"?
See Network Connectivity — Kademlia connectivity.
Searching and sources
In the search window, what filter corresponds to which file type?
The File Type filter classifies results by their filename extension, not by actual content — so a file named Birthday.zip appears under Archives, never under Videos, regardless of what it really contains. The complete extension-to-category mapping (Archives, Audio, CD-Images, Pictures, Programs, Texts, Videos) is documented in Searches → File Type.
What is a source?
A source is a client sharing a chunk of a file you have in your download queue that you have not yet completed. The more sources, the more download opportunities exist.
When you have a Low ID:
- Sources: all clients sharing a chunk or file you still need.
- Available sources: only High ID clients you can actually connect to.
Credits, ratings and scoring
For a full explanation of the upload queue priority system, see eD2k Network — Credits and Scoring and Concepts & Glossary — Credits.
Network speed and protocol overhead
What should I know about network speed?
This section explains the technical factors behind network speed while aMule is running. For simpler troubleshooting advice, see aMule Is Slow.
How fast is my network, really?
Network speed is measured in bits per second (bps). To convert: bytes/s = bps / 8. A provider offering a "600/100 Mbps" fiber plan means 600,000,000/100,000,000 bps, which is 75/12.5 megabytes per second.
Networking uses decimal prefixes, not binary ones:
| Prefix | In computers (binary) | In networking (decimal) | Error |
|---|---|---|---|
| k (kilo) | 2¹⁰ = 1,024 | 10³ = 1,000 | ~2% |
| M (mega) | 2²⁰ = 1,048,576 | 10⁶ = 1,000,000 | ~5% |
| G (giga) | 2³⁰ = 1,073,741,824 | 10⁹ = 1,000,000,000 | ~7% |
| T (tera) | 2⁴⁰ = 1,099,511,627,776 | 10¹² = 1,000,000,000,000 | ~9% |
Your ISP quotes speeds in decimal units. This alone accounts for a ~5% difference between the advertised speed and what applications report. See aMule Is Slow for practical limit values.
What is protocol overhead?
Every piece of control data aMule sends — source requests, search queries, queue negotiations — is overhead: data transmitted but not directly part of your downloads. aMule's reported overhead only counts data sent to the OS network stack; the OS adds TCP/IP headers on top.
For IPv4 TCP/IP: each packet carries a minimum of 20 bytes IPv4 header + 20 bytes TCP header. TCP connection establishment (SYN / SYN+ACK / ACK) requires at least 3 packets per connection. aMule opens new TCP connections in bursts — by default up to 20 every 5 seconds (configurable in Preferences → Advanced → Max new connections / 5 secs; see Slow Download Speeds).
What is the ACK bottleneck?
TCP requires the receiver to send ACK packets back for every segment received. If aMule saturates your uplink with uploads and connection overhead, outgoing ACKs for your downloads may be delayed or dropped — causing the remote sender to slow down, which directly reduces your download speed.
Never use more than 80% of your upload capacity for aMule. Set realistic rate limits in Preferences → Connection → Bandwidth Limits. This applies to any connection — especially asymmetric ones (cable, DSL) where the uplink is the bottleneck — so always leave headroom for ACKs and other traffic rather than running the link at 100%. See aMule Is Slow for specific values.
How do routers and SOHO devices cope with P2P load?
Cheap SOHO routers can struggle with the large number of simultaneous TCP connections and UDP flows generated by P2P traffic. NAT state tables may fill up, causing dropped connections or router instability.
Recommendations:
- Choose a router rated for P2P/heavy-NAT workloads (routers with VPN, built-in downloader, or USB storage typically have stronger CPUs and more RAM).
- Always configure port forwarding for ports 4662 (TCP), 4665 (UDP), 4672 (UDP) — see Network Connectivity — Ports — or enable UPnP.
- Prefer ISP connections that assign IP via DHCP over plain Ethernet rather than PPPoE/PPTP.
Can I use multiple internet connections?
Link redundancy: aMule must be restarted when links switch so it binds to the new IP and receives a new eD2k ID — unless the switchover is handled transparently at the NAT router.
Load balancing: aMule binds to all interfaces (0.0.0.0) but can only advertise one IP as its eD2k ID. Running across two simultaneously active ISP links is unreliable; the only reliable solution is to pin aMule's traffic to one interface.
See Network Connectivity for binding and connectivity details.
Browser configuration for ed2k:// links
See ed2k — Browser Configuration for instructions on configuring Firefox, Chrome, Edge, Safari, and other browsers to handle ed2k:// URIs.
Remote access
Running aMule without a graphical interface and controlling it remotely via amuled, amulecmd, amulegui, and amuleweb.
aMule daemon (amuled)
What is amuled?
amuled is a full-featured aMule that runs without any user interface. It has reduced memory and CPU requirements and can run on a headless server with no X display. It is controlled remotely via amuleweb, amulecmd, or amulegui over the External Connections (EC) protocol.
Do not set Max Connections excessively high when using amuled. The default is around 500, and amuled adapts the recommended maximum to your operating system's limits; setting it far higher wastes resources and can degrade performance. See amuled — Configuration.
See the amuled documentation for setup, configuration, and service installation details.
How do I set up amuled as a system service?
See Running as a System Service in the amuled documentation for init scripts covering systemd, Debian/Ubuntu, Red Hat/Fedora, Gentoo, and SUSE/openSUSE.
amulecmd
How do I schedule actions or write scripts with amulecmd?
See Scheduling with Cron and Useful Scripts in the amulecmd documentation.
amulegui
Is there a remote graphical client for amuled?
Yes. amulegui provides the same interface as the monolithic amule client and connects to amuled over the EC protocol.
See the amulegui documentation for compilation, setup, and connection instructions.
amuleweb
What is amuleweb?
amuleweb is a built-in web server that provides a browser-based interface for controlling aMule or amuled remotely. It listens for HTTP connections on port 4711 (default) and communicates with aMule over the EC protocol on port 4712.
See the amuleweb documentation for detailed setup instructions.
What should I see when amuleweb is running correctly?
After launching amuleweb in a terminal, you should see output like:
Web Server: Started
WSThread: Thread started
WSThread: created service
WSThread: created socket listening on :4711
amuleweb$
Then open a browser and navigate to http://127.0.0.1:4711 (or the remote host's address). For full setup, see the amuleweb documentation.
Can I run amuleweb as a daemon (background process)?
Yes. amuleweb supports the --quiet (-q) flag, which suppresses the interactive prompt and allows easy backgrounding:
amuleweb --quiet &
See the amuleweb documentation for the complete list of command-line options.