diff --git a/.travis.yml b/.travis.yml
index 7d848609..129d203c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,5 +32,6 @@ script:
         cargo clippy --all-targets --all-features -- -D warnings
       fi
   - cargo build --verbose
-  - cargo test --verbose
+  - cargo test --no-default-features --verbose
+  - cargo test --all-features --verbose
 if: "type != push OR (tag IS blank AND branch = master)"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9e40bc5..07fe41d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,10 +19,14 @@ Breaking changes:
     instead of `&url::Host`
 * `Error::InvalidHost` has been renamed to `Error::InvalidServerName`, because it also covers errors
   in the port, not just the host part section of the server name
+* The random identifier generation functions (`Id::new`) are now only available if the `rand`
+  feature of this crate is enabled
 
 Improvements:
 
 * Add support for historical uppercase MXIDs
+* Made all dependencies optional
+  * `serde` is the only one that is enabled by default
 
 # 0.14.1
 
diff --git a/Cargo.toml b/Cargo.toml
index 34d31961..bcaf4d11 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,10 +12,13 @@ repository = "https://github.com/ruma/ruma-identifiers"
 version = "0.14.1"
 edition = "2018"
 
+[features]
+default = ["serde"]
+
 [dependencies]
 diesel = { version = "1.4.4", optional = true }
-rand = "0.7.3"
-serde = "1.0.106"
+rand = { version = "0.7.3", optional = true }
+serde = { version = "1.0.106", optional = true }
 
 [dev-dependencies]
 serde_json = "1.0.51"
diff --git a/src/device_id.rs b/src/device_id.rs
index 549ec2cc..8ee95378 100644
--- a/src/device_id.rs
+++ b/src/device_id.rs
@@ -1,5 +1,6 @@
 //! Matrix device identifiers.
 
+#[cfg(feature = "rand")]
 use crate::generate_localpart;
 
 /// A Matrix device ID.
@@ -9,11 +10,12 @@ use crate::generate_localpart;
 pub type DeviceId = String;
 
 /// Generates a random `DeviceId`, suitable for assignment to a new device.
+#[cfg(feature = "rand")]
 pub fn generate() -> DeviceId {
     generate_localpart(8)
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature = "rand"))]
 mod tests {
     use super::generate;
 
diff --git a/src/event_id.rs b/src/event_id.rs
index 40b1ef37..b93688d6 100644
--- a/src/event_id.rs
+++ b/src/event_id.rs
@@ -5,7 +5,7 @@ use std::{borrow::Cow, convert::TryFrom, num::NonZeroU8};
 #[cfg(feature = "diesel")]
 use diesel::sql_types::Text;
 
-use crate::{error::Error, generate_localpart, is_valid_server_name, parse_id, validate_id};
+use crate::{error::Error, parse_id, validate_id};
 
 /// A Matrix event ID.
 ///
@@ -55,7 +55,10 @@ impl EventId {
     ///
     /// Does not currently ever fail, but may fail in the future if the homeserver cannot be parsed
     /// parsed as a valid host.
+    #[cfg(feature = "rand")]
     pub fn new(server_name: &str) -> Result<Self, Error> {
+        use crate::{generate_localpart, is_valid_server_name};
+
         if !is_valid_server_name(server_name) {
             return Err(Error::InvalidServerName);
         }
@@ -121,6 +124,7 @@ common_impls!(EventId, "a Matrix event ID");
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::EventId;
@@ -156,6 +160,7 @@ mod tests {
         )
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_valid_event_id() {
         let event_id = EventId::new("example.com").expect("Failed to generate EventId.");
@@ -165,11 +170,13 @@ mod tests {
         assert_eq!(id_str.len(), 31);
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_invalid_event_id() {
         assert!(EventId::new("").is_err());
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_original_event_id() {
         assert_eq!(
@@ -181,6 +188,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_base64_event_id() {
         assert_eq!(
@@ -193,6 +201,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_url_safe_base64_event_id() {
         assert_eq!(
@@ -205,6 +214,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_original_event_id() {
         assert_eq!(
@@ -214,6 +224,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_base64_event_id() {
         assert_eq!(
@@ -224,6 +235,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_url_safe_base64_event_id() {
         assert_eq!(
diff --git a/src/lib.rs b/src/lib.rs
index 45bcf63d..8ea4364e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,9 +14,9 @@
 #[cfg_attr(feature = "diesel", macro_use)]
 extern crate diesel;
 
-use std::{borrow::Cow, convert::TryFrom, num::NonZeroU8};
+use std::num::NonZeroU8;
 
-use rand::{distributions::Alphanumeric, thread_rng, Rng};
+#[cfg(feature = "serde")]
 use serde::de::{self, Deserialize as _, Deserializer, Unexpected};
 
 #[doc(inline)]
@@ -51,9 +51,11 @@ const MAX_BYTES: usize = 255;
 const MIN_CHARS: usize = 4;
 
 /// Generates a random identifier localpart.
+#[cfg(feature = "rand")]
 fn generate_localpart(length: usize) -> String {
-    thread_rng()
-        .sample_iter(&Alphanumeric)
+    use rand::Rng as _;
+    rand::thread_rng()
+        .sample_iter(&rand::distributions::Alphanumeric)
         .take(length)
         .collect()
 }
@@ -95,12 +97,13 @@ fn parse_id(id: &str, valid_sigils: &[char]) -> Result<NonZeroU8, Error> {
 /// Deserializes any type of id using the provided TryFrom implementation.
 ///
 /// This is a helper function to reduce the boilerplate of the Deserialize implementations.
+#[cfg(feature = "serde")]
 fn deserialize_id<'de, D, T>(deserializer: D, expected_str: &str) -> Result<T, D::Error>
 where
     D: Deserializer<'de>,
-    T: for<'a> TryFrom<&'a str>,
+    T: for<'a> std::convert::TryFrom<&'a str>,
 {
-    Cow::<'_, str>::deserialize(deserializer).and_then(|v| {
+    std::borrow::Cow::<'_, str>::deserialize(deserializer).and_then(|v| {
         T::try_from(&v).map_err(|_| de::Error::invalid_value(Unexpected::Str(&v), &expected_str))
     })
 }
diff --git a/src/macros.rs b/src/macros.rs
index 8daf46f1..b823ff20 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -63,6 +63,7 @@ macro_rules! common_impls {
             }
         }
 
+        #[cfg(feature = "serde")]
         impl ::serde::Serialize for $id {
             fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where
@@ -72,6 +73,7 @@ macro_rules! common_impls {
             }
         }
 
+        #[cfg(feature = "serde")]
         impl<'de> ::serde::Deserialize<'de> for $id {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
diff --git a/src/room_alias_id.rs b/src/room_alias_id.rs
index 6bf23924..2649621b 100644
--- a/src/room_alias_id.rs
+++ b/src/room_alias_id.rs
@@ -62,6 +62,7 @@ common_impls!(RoomAliasId, "a Matrix room alias ID");
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::RoomAliasId;
@@ -77,6 +78,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_room_alias_id() {
         assert_eq!(
@@ -88,6 +90,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_room_alias_id() {
         assert_eq!(
diff --git a/src/room_id.rs b/src/room_id.rs
index 9505ac3e..9d2ae762 100644
--- a/src/room_id.rs
+++ b/src/room_id.rs
@@ -5,7 +5,7 @@ use std::{borrow::Cow, convert::TryFrom, num::NonZeroU8};
 #[cfg(feature = "diesel")]
 use diesel::sql_types::Text;
 
-use crate::{error::Error, generate_localpart, is_valid_server_name, parse_id};
+use crate::{error::Error, parse_id};
 
 /// A Matrix room ID.
 ///
@@ -33,7 +33,10 @@ impl RoomId {
     /// 18 random ASCII characters.
     ///
     /// Fails if the given homeserver cannot be parsed as a valid host.
+    #[cfg(feature = "rand")]
     pub fn new(server_name: &str) -> Result<Self, Error> {
+        use crate::{generate_localpart, is_valid_server_name};
+
         if !is_valid_server_name(server_name) {
             return Err(Error::InvalidServerName);
         }
@@ -79,6 +82,7 @@ common_impls!(RoomId, "a Matrix room ID");
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::RoomId;
@@ -94,6 +98,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_valid_room_id() {
         let room_id = RoomId::new("example.com").expect("Failed to generate RoomId.");
@@ -103,11 +108,13 @@ mod tests {
         assert_eq!(id_str.len(), 31);
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_invalid_room_id() {
         assert!(RoomId::new("").is_err());
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_room_id() {
         assert_eq!(
@@ -119,6 +126,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_room_id() {
         assert_eq!(
diff --git a/src/room_id_or_room_alias_id.rs b/src/room_id_or_room_alias_id.rs
index 9023824c..fe7ab364 100644
--- a/src/room_id_or_room_alias_id.rs
+++ b/src/room_id_or_room_alias_id.rs
@@ -93,6 +93,7 @@ common_impls!(RoomIdOrAliasId, "a Matrix room ID or room alias ID");
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::RoomIdOrAliasId;
@@ -126,6 +127,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_room_id_or_alias_id_with_a_room_alias_id() {
         assert_eq!(
@@ -138,6 +140,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_room_id_or_alias_id_with_a_room_id() {
         assert_eq!(
@@ -150,6 +153,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_room_id_or_alias_id_with_a_room_alias_id() {
         assert_eq!(
@@ -159,6 +163,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_room_id_or_alias_id_with_a_room_id() {
         assert_eq!(
diff --git a/src/room_version_id.rs b/src/room_version_id.rs
index 5e8d8d35..603a5085 100644
--- a/src/room_version_id.rs
+++ b/src/room_version_id.rs
@@ -8,9 +8,10 @@ use std::{
 
 #[cfg(feature = "diesel")]
 use diesel::sql_types::Text;
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
-use crate::{deserialize_id, error::Error};
+use crate::error::Error;
 
 /// Room version identifiers cannot be more than 32 code points.
 const MAX_CODE_POINTS: usize = 32;
@@ -155,6 +156,7 @@ impl Display for RoomVersionId {
     }
 }
 
+#[cfg(feature = "serde")]
 impl Serialize for RoomVersionId {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -164,12 +166,13 @@ impl Serialize for RoomVersionId {
     }
 }
 
+#[cfg(feature = "serde")]
 impl<'de> Deserialize<'de> for RoomVersionId {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>,
     {
-        deserialize_id(deserializer, "a Matrix room version ID as a string")
+        crate::deserialize_id(deserializer, "a Matrix room version ID as a string")
     }
 }
 
@@ -243,6 +246,7 @@ impl PartialEq<RoomVersionId> for String {
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::RoomVersionId;
@@ -324,6 +328,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_official_room_id() {
         assert_eq!(
@@ -333,6 +338,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_official_room_id() {
         let deserialized =
@@ -347,6 +353,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_custom_room_id() {
         assert_eq!(
@@ -358,6 +365,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_custom_room_id() {
         let deserialized = from_str::<RoomVersionId>(r#""io.ruma.1""#)
diff --git a/src/user_id.rs b/src/user_id.rs
index 63532ccb..31a67100 100644
--- a/src/user_id.rs
+++ b/src/user_id.rs
@@ -5,7 +5,7 @@ use std::{borrow::Cow, convert::TryFrom, num::NonZeroU8};
 #[cfg(feature = "diesel")]
 use diesel::sql_types::Text;
 
-use crate::{error::Error, generate_localpart, is_valid_server_name, parse_id};
+use crate::{error::Error, parse_id};
 
 /// A Matrix user ID.
 ///
@@ -39,7 +39,10 @@ impl UserId {
     /// 12 random ASCII characters.
     ///
     /// Fails if the given homeserver cannot be parsed as a valid host.
+    #[cfg(feature = "rand")]
     pub fn new(server_name: &str) -> Result<Self, Error> {
+        use crate::{generate_localpart, is_valid_server_name};
+
         if !is_valid_server_name(server_name) {
             return Err(Error::InvalidServerName);
         }
@@ -108,6 +111,7 @@ common_impls!(UserId, "a Matrix user ID");
 mod tests {
     use std::convert::TryFrom;
 
+    #[cfg(feature = "serde")]
     use serde_json::{from_str, to_string};
 
     use super::UserId;
@@ -134,6 +138,7 @@ mod tests {
         assert!(user_id.is_historical());
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_valid_user_id() {
         let user_id = UserId::new("example.com").expect("Failed to generate UserId.");
@@ -146,11 +151,13 @@ mod tests {
         assert_eq!(id_str.len(), 25);
     }
 
+    #[cfg(feature = "rand")]
     #[test]
     fn generate_random_invalid_user_id() {
         assert!(UserId::new("").is_err());
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn serialize_valid_user_id() {
         assert_eq!(
@@ -160,6 +167,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "serde")]
     #[test]
     fn deserialize_valid_user_id() {
         assert_eq!(