Settings Reference

Open Settings from the top bar’s gear icon. The settings sidebar has nine categories, in this order: General, Appearance, Download, BitTorrent, eD2K, Proxy, API Service, Extensions, and About. This page documents every setting in each one, along with its default value. The Extensions category hosts plugin management and optional external components (FFmpeg, yt-dlp) in two tabs — see the Plugins docs for those. A search box at the top of the Settings sidebar can jump straight to any setting by name.

General

Setting	Purpose	Default
Launch at Startup	Automatically run FluxDown when the system starts.	Off
Minimize to Tray on Close	Hide to the system tray instead of quitting when you click the close button.	On
Desktop Floating Ball	An always-on-top desktop widget showing download speed and progress; drag URLs or torrent files onto it to start a download. Unavailable on Wayland (see the note below).	Off
Clipboard Watcher (Linux Wayland only)	While the main window is hidden, watch the clipboard for download links and notify you. Only shown as a fallback when the floating ball is unavailable on Wayland.	Off
Associate .torrent Files	Make FluxDown the default handler for .torrent files. FluxDown prompts once on first launch if this hasn’t been set.	Off
Completion Notifications	Show a system notification when a task finishes.	On
Keep Awake While Downloading	Prevent the system from sleeping or turning off the display while any task is downloading; restores automatically once idle.	Off
Sidebar Sections (Status / Queues / Category)	Choose which of the three sidebar sections are visible. Turning all three off hides the sidebar entirely.	All on
Titlebar Buttons (Pause All / Resume All / Settings / Theme)	Choose which tool buttons appear in the top bar; you can also right-click a button to hide it directly.	All on
Custom Categories	Define extra file-type filters for the sidebar’s Category section, matched by extension or regular expression.	None

Appearance

Setting	Purpose	Default
Language	Interface language: follow system, Chinese, or English.	Follow System
Theme Mode	Light, dark, or follow system.	Follow System
Theme	Five built-in themes, filtered to the current light/dark mode: Default Dark, Midnight Blue, and Nord for dark mode; Default Light and Warm Light for light mode. You can also import a custom theme JSON and export the current one.	Default Dark / Default Light
Theme Color	The app’s accent color: Blue, Green, Violet, Rose, or Custom (hue slider + hex input).	Blue
Interface Scale	Overall UI scale, from 80% to 150%.	100%
App Icon (Windows only)	Choose the icon used by the window, taskbar, and tray: the built-in icon, a built-in “bolt” alternative, or a custom image you provide.	Built-in icon

Download

Setting	Purpose	Default
Default Save Directory	Where new downloads are saved unless you pick another folder or a queue overrides it.	Platform downloads folder
Remember Last Save Location	Use the folder from your last download as the default for the next one, instead of the fixed directory above.	Off
Silent Download	Skip the confirmation dialog for external download requests (e.g. from the browser extension) and start them immediately with default settings.	Off
Default Threads	Default segment count for new downloads (0 = automatic, based on file size and CPU count).	Auto
Max Concurrent Downloads	Maximum number of tasks downloading at the same time, across all queues that don’t override it.	5
Speed Limit	Global download speed cap in KB/s (0 = unlimited). Also editable from the status bar.	0 (unlimited)
Auto-retry Attempts	Automatic retries after transient errors like network drops (-1 = unlimited, 0 = off).	3
Retry Interval	Seconds to wait before each automatic retry.	5
User-Agent	The browser identity sent with download requests; presets for Chrome/Firefox/Edge/Safari. Empty uses the built-in Chrome UA.	Empty (built-in Chrome UA)
File manager command	Custom command template for opening a file or folder in a third-party manager. Placeholders: {path} (current path) and {dir} (folder). Empty uses the platform default (Explorer/Finder/Nautilus).	Empty
Default Queue	Which queue new downloads join when none is explicitly chosen (used by the browser extension too).	Main Queue (built-in)

Third-party file managers

“Show in Folder” and “Open Folder” follow your system’s default file manager, so most setups need no configuration:

• Windows — respects the default folder handler registered under Directory\shell (the app that opens when you double-click a folder). A third-party manager set as the default is used automatically. OneCommander is supported out of the box this way; Directory Opus, Total Commander, Files, and other managers that register themselves as the default folder handler are picked up the same way. Because Windows lets only Explorer select a specific file, when a third-party manager is the default, “Show in Folder” opens the containing folder instead of highlighting the file.
• macOS — uses the Launch Services default for public.folder.
• Linux — uses the inode/directory default from mimeapps.list (via xdg-open).

To use a manager that is not your system default — or to highlight the exact file inside a third-party manager — fill in the File manager command template above. One command covers both “Show in Folder” (a downloaded file) and “Open Folder” (a directory); FluxDown fills the placeholders according to the case. Placeholders are already shell-quoted, so don’t add your own quotes around them — but the executable path still needs quotes if it contains spaces:

• {path} — the current path: the full file path when showing a file, the folder path when opening a directory.
• {dir} — the directory (the file’s parent when showing a file, the folder itself when opening a directory).

Example commands on Windows (adjust the install path; use {path} for managers that can navigate to a specific file, {dir} for those that only open a folder):

Manager	Command
OneCommander	"C:\Program Files\OneCommander\OneCommander.exe" {path}
Everything	"C:\Program Files\Everything\Everything.exe" -select {path}
Directory Opus	"C:\Program Files\GPSoftware\Directory Opus\dopusrt.exe" /cmd Go {path} NEW
Total Commander	"C:\totalcmd\TOTALCMD64.EXE" /O /T {dir}

A configured template always takes priority over auto-detection; if it fails to launch, FluxDown falls back to the platform default.

BitTorrent

Setting	Purpose	Default
Listen Port Range	The port range FluxDown listens on for incoming BT connections.	6881–6891
Tracker List	Custom tracker servers for peer discovery, one per line, on top of 25 built-in trackers (Asia-priority ordering). Can be reset to the built-in list.	25 built-in trackers
Tracker Subscription	Periodically fetch up-to-date trackers from community-maintained lists and merge them with the list above.	On

Some BT changes require restarting the BT engine to take effect (FluxDown shows a reminder in this category). DHT and UPnP are always enabled internally and have no separate toggle. Proxy settings (below) don’t apply to BitTorrent downloads.

eD2K

Setting	Purpose	Default
Server List	Manually added eD2K servers (host:port, one per line) for finding sources, merged with the subscription list.	Empty
Server Subscription	Periodically fetch up-to-date servers from community-maintained server.met lists and merge them with the list above.	On
Kad DHT source finding	Find sources via the decentralized Kad network, even when all servers are unreachable.	On
UPnP port mapping	Automatically map a port via UPnP to obtain a HighID, improving connectivity.	On
Listen port	TCP/UDP port for the eD2K client (0 = let the OS choose).	0 (auto)

Proxy

Setting	Purpose	Default
Mode	No Proxy, System Proxy (read from OS settings), or Manual.	No Proxy
Type (Manual mode)	HTTP, HTTPS, SOCKS4, or SOCKS5.	HTTP
Server Address / Port (Manual mode)	The proxy server’s host and port.	Empty
Username / Password (Manual mode)	Optional proxy authentication.	Empty
Bypass List	Comma-separated addresses that skip the proxy entirely.	Empty
Test Connection	Verifies the configured proxy and reports latency or an error.	—

Proxy settings apply to HTTP/HTTPS/FTP/eD2K downloads only — BitTorrent downloads always connect directly.

API Service

A local-only HTTP API (127.0.0.1) used by the browser extension, aria2-compatible tools, and automation scripts.

Setting	Purpose	Default
Enable API Service	Master switch for the local HTTP server; the three feature toggles below only work while this is on.	On
Listen Port	The port the local server binds to (1024–65535).	17800
Access Token	Token used to authenticate API requests; generate or copy it with the buttons next to the field. Required once Management API is enabled.	Empty
Browser Script Takeover	Lets the FluxDown userscript take over browser downloads at http://127.0.0.1:<port>. Includes a button to copy the userscript.	On
aria2 RPC Compatible	Implements the aria2 JSON-RPC protocol (addUri, getVersion, getGlobalStat, multicall, …) at /jsonrpc, for “send to aria2” scripts or clients like AriaNg.	On
Management API	An HTTP API for querying and controlling tasks at /api/v1, for MCP servers and automation scripts. Always requires the access token.	Off

See the API documentation for the full endpoint reference.

About

Item	Purpose	Default
Version info	Shows the current version, plus the latest available version and its publish date once an update is found.	—
Auto-check for Updates	Silently check GitHub Releases for a newer version shortly after startup. Also exposes manual Check Now / Download / Install & Restart actions.	On
Max Log Size	Total size cap for FluxDown’s log files (5/10/20/50/100 MB); the oldest logs are cleaned automatically once the cap is exceeded.	10 MB
Export Logs	Package recent logs into a .zip for attaching to a bug report, or open the log folder directly.	—