It is not always possible to set all configurations from the GUI, especially for the daemon or the web interface. This guide will try to give an overview of how and what you can change. For the location of these files, look at the [Configuration Files](Configuration-Files.md) page.
* **announce-ip:** String (default = "") Alternative IP address to announce to the tracker.
* **announce-ip-enabled:** Boolean (default = false) When enabled **announce-ip** value is used instead of the client's address visible to the tracker for announcement requests.
_Note: Clicking the "Turtle" in the GUI when the [scheduler](#Scheduling) is enabled, will only temporarily remove the scheduled limit until the next cycle._
* **incomplete-dir-enabled:** Boolean (default = false) When enabled, new torrents will download the files to **incomplete-dir**. When complete, the files will be moved to **download-dir**.
* **preallocation:** Number (0 = Off, 1 = Fast, 2 = Full (slower but reduces disk fragmentation), default = 1)
* **trash-can-enabled:** Boolean (default = true) Whether to move the torrents to the system's trashcan or unlink them right away upon deletion from Transmission.
_Note: When **watch-dir-enabled** is true, only the transmission-daemon, transmission-gtk, and transmission-qt applications will monitor **watch-dir** for new .torrent files and automatically load them._
* **cache-size-mb:** Number (default = 4), in megabytes, to allocate for Transmission's memory cache. The cache is used to help batch disk IO together, so increasing the cache size can be used to reduce the number of disk reads and writes. The value is the total available to the Transmission instance. Setting this to 0 bypasses the cache, which may be useful if your filesystem already has a cache layer that aggregates transactions.
* **default-trackers:** String (default = "") A list of double-newline separated tracker announce URLs. These are used for all torrents in addition to the per torrent trackers specified in the torrent file. If a tracker is only meant to be a backup, it should be separated from its main tracker by a single newline character. If a tracker should be used additionally to another tracker it should be separated by two newlines. (e.g. "udp://tracker.example.invalid:1337/announce\n\nudp://tracker.another-example.invalid:6969/announce\nhttps://backup-tracker.another-example.invalid:443/announce\n\nudp://tracker.yet-another-example.invalid:1337/announce", in this case tracker.example.invalid, tracker.another-example.invalid and tracker.yet-another-example.invalid would be used as trackers and backup-tracker.another-example.invalid as backup in case tracker.another-example.invalid is unreachable.
* **encryption:** Number (0 = Prefer unencrypted connections, 1 = Prefer encrypted connections, 2 = Require encrypted connections; default = 1) [Encryption](https://wiki.vuze.com/w/Message_Stream_Encryption) preference. Encryption may help get around some ISP filtering, but at the cost of slightly higher CPU use.
* **lazy-bitfield-enabled:** Boolean (default = true) May help get around some ISP filtering. [Vuze specification](https://wiki.vuze.com/w/Commandline_options#Network_Options).
* **prefetch-enabled:** Boolean (default = true). When enabled, Transmission will hint to the OS which piece data it's about to read from disk in order to satisfy requests from peers. On Linux, this is done by passing `POSIX_FADV_WILLNEED` to [posix_fadvise()](https://www.kernel.org/doc/man-pages/online/pages/man2/posix_fadvise.2.html). On macOS, this is done by passing `F_RDADVISE` to [fcntl()](https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/fcntl.2.html).
* **script-torrent-added-enabled:** Boolean (default = false) Run a script when a torrent is added to Transmission. Environmental variables are passed in as detailed on the [Scripts](./Scripts.md) page
* **script-torrent-added-filename:** String (default = "") Path to script.
* **script-torrent-done-enabled:** Boolean (default = false) Run a script when a torrent is done downloading. Environmental variables are passed in as detailed on the [Scripts](./Scripts.md) page
* **script-torrent-done-seeding-enabled:** Boolean (default = false) Run a script when a torrent is done seeding. Environmental variables are passed in as detailed on the [Scripts](./Scripts.md) page
* **script-torrent-done-seeding-filename:** String (default = "") Path to script.
* **tcp-enabled:** Boolean (default = true) Optionally disable TCP connection to other peers. Never disable TCP when you also disable UTP, because then your client would not be able to communicate. Disabling TCP might also break webseeds. Unless you have a good reason, you should not set this to false.
* **torrent-added-verify-mode:** String ("fast", "full", default: "fast") Whether newly-added torrents' local data should be fully verified when added, or wait and verify them on-demand later. See [#2626](https://github.com/transmission/transmission/pull/2626) for more discussion.
* **bind-address-ipv4:** String (default = "0.0.0.0") Where to listen for peer connections. When no valid IPv4 address is provided, Transmission will bind to "0.0.0.0".
* **bind-address-ipv6:** String (default = "::") Where to listen for peer connections. When no valid IPv6 address is provided, Transmission will try to bind to your default global IPv6 address. If that didn't work, then Transmission will bind to "::".
* **peer-socket-tos:** String (default = "default") Set the [Type-Of-Service (TOS)](https://en.wikipedia.org/wiki/Type_of_Service) parameter for outgoing TCP packets. Possible values are "default", "lowcost", "throughput", "lowdelay" and "reliability". The value "lowcost" is recommended if you're using a smart router, and shouldn't harm in any case.
* **queue-stalled-enabled:** Boolean (default = true) When true, torrents that have not shared data for `queue-stalled-minutes` are treated as 'stalled' and are not counted against the `download-queue-size` and `seed-queue-size` limits.
* **anti-brute-force-enabled:**: Boolean (default = false) Enable a very basic brute force protection for the RPC server. See "anti-brute-force-threshold" below.
* **anti-brute-force-threshold:**: Number (default = 100) After this amount of failed authentication attempts is surpassed, the RPC server will deny any further authentication attempts until it is restarted. This is not tracked per IP but in total.
* **rpc-bind-address:** String (default = "0.0.0.0") Where to listen for RPC connections
* **rpc-enabled:** Boolean (default = true)
* **rpc-host-whitelist:** String (Comma-delimited list of domain names. Wildcards allowed using '\*'. Example: "*.foo.org,example.com", Default: "", Always allowed: "localhost", "localhost.", all the IP addresses. Added in v2.93)
* **rpc-host-whitelist-enabled:** Boolean (default = true. Added in v2.93)
* **rpc-password:** String. You can enter this in as plaintext when Transmission is not running, and then Transmission will salt the value on startup and re-save the salted version as a security measure. **Note:** Transmission treats passwords starting with the character `{` as salted, so when you first create your password, the plaintext password you enter must not begin with `{`.
* **rpc-url:** String (default = /transmission/. Added in v2.2)
* **rpc-username:** String
* **rpc-whitelist:** String (Comma-delimited list of IP addresses. Wildcards allowed using '\*'. Example: "127.0.0.\*,192.168.\*.\*", Default: "127.0.0.1")
* **rpc-access-control-list:** String (Comma-delimited list of IP addresses prefixed with "+" or "-". Wildcards allowed using '\*'. Example: "+127.0.0.\*,-192.168.\*.\*", Default: "+127.0.0.1")
macOS has a standardized way of saving user preferences files using [XML](https://en.wikipedia.org/wiki/XML) format. These files are called [plist](https://en.wikipedia.org/wiki/Plist) (short for property list) files. Usually there is no need to modify these files directly, since Apple provided a [command-line tool](https://developer.apple.com/DOCUMENTATION/Darwin/Reference/ManPages/man1/defaults.1.html) to reliably change settings. You do need to restart Transmission before these have effect.
