diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index 189f85013c..046712c0af 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -1449,6 +1449,7 @@ dependencies = [
  "sc-executor",
  "sc-service",
  "sp-core",
+ "sp-externalities",
  "sp-runtime",
  "sp-state-machine",
  "structopt",
@@ -4225,6 +4226,7 @@ dependencies = [
 name = "pallet-im-online"
 version = "2.0.0-alpha.4"
 dependencies = [
+ "frame-benchmarking",
  "frame-support",
  "frame-system",
  "pallet-authorship",
diff --git a/substrate/bin/node/runtime/Cargo.toml b/substrate/bin/node/runtime/Cargo.toml
index a5fad30837..bdbf4cce50 100644
--- a/substrate/bin/node/runtime/Cargo.toml
+++ b/substrate/bin/node/runtime/Cargo.toml
@@ -139,4 +139,7 @@ runtime-benchmarks = [
 	"pallet-identity/runtime-benchmarks",
 	"pallet-balances/runtime-benchmarks",
 	"pallet-vesting/runtime-benchmarks",
+	"pallet-session-benchmarking",
+	"pallet-staking/runtime-benchmarks",
+	"pallet-im-online/runtime-benchmarks",
 ]
diff --git a/substrate/bin/node/runtime/src/lib.rs b/substrate/bin/node/runtime/src/lib.rs
index b27ba6c9ac..48913b7771 100644
--- a/substrate/bin/node/runtime/src/lib.rs
+++ b/substrate/bin/node/runtime/src/lib.rs
@@ -864,6 +864,13 @@ impl_runtime_apis! {
 					steps,
 					repeat,
 				),
+				b"pallet-im-online" | b"im-online" => ImOnline::run_benchmark(
+					extrinsic,
+					lowest_range_values,
+					highest_range_values,
+					steps,
+					repeat,
+				),
 				b"pallet-identity" | b"identity" => Identity::run_benchmark(
 					extrinsic,
 					lowest_range_values,
diff --git a/substrate/frame/im-online/Cargo.toml b/substrate/frame/im-online/Cargo.toml
index 2b9e80ce4e..d8df22a0f5 100644
--- a/substrate/frame/im-online/Cargo.toml
+++ b/substrate/frame/im-online/Cargo.toml
@@ -22,6 +22,8 @@ sp-staking = { version = "2.0.0-alpha.4", default-features = false, path = "../.
 frame-support = { version = "2.0.0-alpha.4", default-features = false, path = "../support" }
 frame-system = { version = "2.0.0-alpha.4", default-features = false, path = "../system" }
 
+frame-benchmarking = { version = "2.0.0-alpha.4", default-features = false, path = "../benchmarking", optional = true }
+
 [features]
 default = ["std", "pallet-session/historical"]
 std = [
@@ -38,3 +40,4 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 ]
+runtime-benchmarks = ["frame-benchmarking"]
diff --git a/substrate/frame/im-online/src/benchmarking.rs b/substrate/frame/im-online/src/benchmarking.rs
new file mode 100644
index 0000000000..1269328634
--- /dev/null
+++ b/substrate/frame/im-online/src/benchmarking.rs
@@ -0,0 +1,123 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! I'm Online pallet benchmarking.
+
+#![cfg(feature = "runtime-benchmarks")]
+
+use super::*;
+
+use frame_system::RawOrigin;
+use frame_benchmarking::benchmarks;
+use sp_core::offchain::{OpaquePeerId, OpaqueMultiaddr};
+use sp_runtime::traits::{ValidateUnsigned, Zero};
+
+use crate::Module as ImOnline;
+
+const MAX_KEYS: u32 = 1000;
+const MAX_EXTERNAL_ADDRESSES: u32 = 100;
+
+pub fn create_heartbeat<T: Trait>(k: u32, e: u32) ->
+	Result<(crate::Heartbeat<T::BlockNumber>, <T::AuthorityId as RuntimeAppPublic>::Signature), &'static str>
+{
+	let mut keys = Vec::new();
+	for _ in 0..k {
+		keys.push(T::AuthorityId::generate_pair(None));
+	}
+	Keys::<T>::put(keys.clone());
+
+	let network_state = OpaqueNetworkState {
+		peer_id: OpaquePeerId::default(),
+		external_addresses: vec![OpaqueMultiaddr::new(vec![0; 32]); e as usize],
+	};
+	let input_heartbeat = Heartbeat {
+		block_number: T::BlockNumber::zero(),
+		network_state,
+		session_index: 0,
+		authority_index: k-1,
+	};
+
+	let encoded_heartbeat = input_heartbeat.encode();
+	let authority_id = keys.get((k-1) as usize).ok_or("out of range")?;
+	let signature = authority_id.sign(&encoded_heartbeat).ok_or("couldn't make signature")?;
+
+	Ok((input_heartbeat, signature))
+}
+
+benchmarks! {
+	_{ }
+
+	heartbeat {
+		let k in 1 .. MAX_KEYS;
+		let e in 1 .. MAX_EXTERNAL_ADDRESSES;
+		let (input_heartbeat, signature) = create_heartbeat::<T>(k, e)?;
+	}: _(RawOrigin::None, input_heartbeat, signature)
+
+	validate_unsigned {
+		let k in 1 .. MAX_KEYS;
+		let e in 1 .. MAX_EXTERNAL_ADDRESSES;
+		let (input_heartbeat, signature) = create_heartbeat::<T>(k, e)?;
+		let call = Call::heartbeat(input_heartbeat, signature);
+	}: {
+		ImOnline::<T>::validate_unsigned(&call)?;
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use crate::*;
+	use super::SelectedBenchmark;
+	use crate::mock::*;
+	use frame_support::assert_ok;
+
+	#[test]
+	fn test_heartbeat_benchmark() {
+		new_test_ext().execute_with(|| {
+			let k = 10;
+
+			assert_eq!(ReceivedHeartbeats::iter_prefix(0).count(), 0);
+
+			let selected_benchmark = SelectedBenchmark::heartbeat;
+			let c = vec![(frame_benchmarking::BenchmarkParameter::k, k)];
+			let closure_to_benchmark =
+				<SelectedBenchmark as frame_benchmarking::BenchmarkingSetup<Runtime>>::instance(
+					&selected_benchmark,
+					&c
+				).unwrap();
+
+			assert_ok!(closure_to_benchmark());
+
+			assert_eq!(ReceivedHeartbeats::iter_prefix(0).count(), 1);
+		});
+	}
+
+	#[test]
+	fn test_validate_unsigned_benchmark() {
+		new_test_ext().execute_with(|| {
+			let k = 10;
+
+			let selected_benchmark = SelectedBenchmark::validate_unsigned;
+			let c = vec![(frame_benchmarking::BenchmarkParameter::k, k)];
+			let closure_to_benchmark =
+				<SelectedBenchmark as frame_benchmarking::BenchmarkingSetup<Runtime>>::instance(
+					&selected_benchmark,
+					&c
+				).unwrap();
+
+			assert_ok!(closure_to_benchmark());
+		});
+	}
+}
diff --git a/substrate/frame/im-online/src/lib.rs b/substrate/frame/im-online/src/lib.rs
index a0a16c46f3..861c57e5b6 100644
--- a/substrate/frame/im-online/src/lib.rs
+++ b/substrate/frame/im-online/src/lib.rs
@@ -69,6 +69,7 @@
 
 mod mock;
 mod tests;
+mod benchmarking;
 
 use sp_application_crypto::RuntimeAppPublic;
 use codec::{Encode, Decode};
diff --git a/substrate/primitives/runtime/src/traits.rs b/substrate/primitives/runtime/src/traits.rs
index 39e015505b..81b7733319 100644
--- a/substrate/primitives/runtime/src/traits.rs
+++ b/substrate/primitives/runtime/src/traits.rs
@@ -1293,6 +1293,16 @@ impl Printable for &str {
 	}
 }
 
+impl Printable for bool {
+	fn print(&self) {
+		if *self {
+			"true".print()
+		} else {
+			"false".print()
+		}
+	}
+}
+
 #[impl_for_tuples(1, 12)]
 impl Printable for Tuple {
 	fn print(&self) {
diff --git a/substrate/utils/frame/benchmarking-cli/Cargo.toml b/substrate/utils/frame/benchmarking-cli/Cargo.toml
index 3535a542d9..3ba1b16481 100644
--- a/substrate/utils/frame/benchmarking-cli/Cargo.toml
+++ b/substrate/utils/frame/benchmarking-cli/Cargo.toml
@@ -16,6 +16,7 @@ sc-cli = { version = "0.8.0-alpha.4", path = "../../../client/cli" }
 sc-client = { version = "0.8.0-alpha.4", path = "../../../client" }
 sc-client-db = { version = "0.8.0-alpha.4", path = "../../../client/db" }
 sc-executor = { version = "0.8.0-alpha.4", path = "../../../client/executor" }
+sp-externalities = { version = "0.8.0-alpha.4", path = "../../../primitives/externalities" }
 sp-runtime = { version = "2.0.0-alpha.4", path = "../../../primitives/runtime" }
 sp-state-machine = { version = "0.8.0-alpha.4", path = "../../../primitives/state-machine" }
 structopt = "0.3.8"
diff --git a/substrate/utils/frame/benchmarking-cli/src/lib.rs b/substrate/utils/frame/benchmarking-cli/src/lib.rs
index 79e7e689a6..b2aa4bd6a2 100644
--- a/substrate/utils/frame/benchmarking-cli/src/lib.rs
+++ b/substrate/utils/frame/benchmarking-cli/src/lib.rs
@@ -23,7 +23,12 @@ use sc_service::{Configuration, ChainSpec};
 use sc_executor::{NativeExecutor, NativeExecutionDispatch};
 use codec::{Encode, Decode};
 use frame_benchmarking::BenchmarkResults;
-use sp_core::tasks;
+use sp_core::{
+	tasks,
+	traits::KeystoreExt,
+	testing::KeyStore,
+};
+use sp_externalities::Extensions;
 
 /// The `benchmark` command used to benchmark FRAME Pallets.
 #[derive(Debug, structopt::StructOpt, Clone)]
@@ -106,6 +111,9 @@ impl BenchmarkCmd {
 			2, // The runtime instances cache size.
 		);
 
+		let mut extensions = Extensions::default();
+		extensions.register(KeystoreExt(KeyStore::new()));
+
 		let result = StateMachine::<_, _, NumberFor<BB>, _>::new(
 			&state,
 			None,
@@ -120,7 +128,7 @@ impl BenchmarkCmd {
 				self.steps.clone(),
 				self.repeat,
 			).encode(),
-			Default::default(),
+			extensions,
 			&sp_state_machine::backend::BackendRuntimeCode::new(&state).runtime_code()?,
 			tasks::executor(),
 		)