diff --git a/Cargo.lock b/Cargo.lock
index c97968ef..13b97d2c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -95,6 +95,9 @@ name = "cc"
 version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
+dependencies = [
+ "jobserver",
+]
 
 [[package]]
 name = "cfg-if"
@@ -429,6 +432,7 @@ dependencies = [
  "serde_bytes",
  "sled",
  "tokio",
+ "zstd",
 ]
 
 [[package]]
@@ -779,6 +783,15 @@ version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
+[[package]]
+name = "jobserver"
+version = "0.1.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c71313ebb9439f74b00d9d2dcec36440beaf57a6aa0623068441dd7cd81a7f2"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.49"
@@ -1769,3 +1782,32 @@ name = "xxhash-rust"
 version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e575e15bedf6e57b5c2d763ffc6c3c760143466cbd09d762d539680ab5992ded"
+
+[[package]]
+name = "zstd"
+version = "0.6.1+zstd.1.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5de55e77f798f205d8561b8fe2ef57abfb6e0ff2abe7fd3c089e119cdb5631a3"
+dependencies = [
+ "zstd-safe",
+]
+
+[[package]]
+name = "zstd-safe"
+version = "3.0.1+zstd.1.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1387cabcd938127b30ce78c4bf00b30387dddf704e3f0881dbc4ff62b5566f8c"
+dependencies = [
+ "libc",
+ "zstd-sys",
+]
+
+[[package]]
+name = "zstd-sys"
+version = "1.4.20+zstd.1.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebd5b733d7cf2d9447e2c3e76a5589b4f5e5ae065c22a2bc0b023cbc331b6c8e"
+dependencies = [
+ "cc",
+ "libc",
+]
diff --git a/script/test-smoke.sh b/script/test-smoke.sh
index a2ffcea1..05286c65 100755
--- a/script/test-smoke.sh
+++ b/script/test-smoke.sh
@@ -23,39 +23,43 @@ dd if=/dev/urandom of=/tmp/garage.1.rnd bs=1k count=2 # < INLINE_THRESHOLD = 307
 dd if=/dev/urandom of=/tmp/garage.2.rnd bs=1M count=5
 dd if=/dev/urandom of=/tmp/garage.3.rnd bs=1M count=10
 
+dd if=/dev/urandom bs=1k count=2  | base64 -w0 > /tmp/garage.1.b64
+dd if=/dev/urandom bs=1M count=5  | base64 -w0 > /tmp/garage.2.b64
+dd if=/dev/urandom bs=1M count=10 | base64 -w0 > /tmp/garage.3.b64
+
 echo "s3 api testing..."
-for idx in $(seq 1 3); do
+for idx in {1,2,3}.{rnd,b64}; do
   # AWS sends	
-  awsgrg cp /tmp/garage.$idx.rnd s3://eprouvette/garage.$idx.aws
+  awsgrg cp /tmp/garage.$idx s3://eprouvette/garage.$idx.aws
   
   awsgrg ls s3://eprouvette
   
   awsgrg cp s3://eprouvette/garage.$idx.aws /tmp/garage.$idx.dl
-  diff /tmp/garage.$idx.rnd /tmp/garage.$idx.dl
+  diff /tmp/garage.$idx /tmp/garage.$idx.dl
   rm /tmp/garage.$idx.dl
   
   s3grg get s3://eprouvette/garage.$idx.aws /tmp/garage.$idx.dl
-  diff /tmp/garage.$idx.rnd /tmp/garage.$idx.dl
+  diff /tmp/garage.$idx /tmp/garage.$idx.dl
   rm /tmp/garage.$idx.dl
   
   awsgrg rm s3://eprouvette/garage.$idx.aws
 
   # S3CMD sends
-  s3grg put /tmp/garage.$idx.rnd s3://eprouvette/garage.$idx.s3cmd
+  s3grg put /tmp/garage.$idx s3://eprouvette/garage.$idx.s3cmd
 
   s3grg ls s3://eprouvette
 	
   s3grg get s3://eprouvette/garage.$idx.s3cmd /tmp/garage.$idx.dl
-  diff /tmp/garage.$idx.rnd /tmp/garage.$idx.dl
+  diff /tmp/garage.$idx /tmp/garage.$idx.dl
   rm /tmp/garage.$idx.dl
   
   awsgrg cp s3://eprouvette/garage.$idx.s3cmd /tmp/garage.$idx.dl
-  diff /tmp/garage.$idx.rnd /tmp/garage.$idx.dl
+  diff /tmp/garage.$idx /tmp/garage.$idx.dl
   rm /tmp/garage.$idx.dl
 	
   s3grg rm s3://eprouvette/garage.$idx.s3cmd
 done
-rm /tmp/garage.{1,2,3}.rnd
+rm /tmp/garage.{1,2,3}.{rnd,b64}
 
 echo "website testing"
 echo "<h1>hello world</h1>" > /tmp/garage-index.html
diff --git a/src/model/Cargo.toml b/src/model/Cargo.toml
index 77084531..1b97e4f9 100644
--- a/src/model/Cargo.toml
+++ b/src/model/Cargo.toml
@@ -21,8 +21,8 @@ arc-swap = "1.0"
 hex = "0.4"
 log = "0.4"
 rand = "0.8"
-
 sled = "0.34"
+zstd = "0.6.1"
 
 rmp-serde = "0.15"
 serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
diff --git a/src/model/block.rs b/src/model/block.rs
index 5f428fe1..699ff32d 100644
--- a/src/model/block.rs
+++ b/src/model/block.rs
@@ -9,6 +9,7 @@ use serde::{Deserialize, Serialize};
 use tokio::fs;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::sync::{watch, Mutex, Notify};
+use zstd::stream::{decode_all as zstd_decode, Encoder};
 
 use garage_util::data::*;
 use garage_util::error::Error;
@@ -42,22 +43,37 @@ pub enum Message {
 	GetBlock(Hash),
 	/// Message to send a block of data, either because requested, of for first delivery of new
 	/// block
-	PutBlock(PutBlockMessage),
+	PutBlock {
+		hash: Hash,
+		data: BlockData,
+	},
 	/// Ask other node if they should have this block, but don't actually have it
 	NeedBlockQuery(Hash),
 	/// Response : whether the node do require that block
 	NeedBlockReply(bool),
 }
 
-/// Structure used to send a block
+/// A possibly compressed block of data
 #[derive(Debug, Serialize, Deserialize)]
-pub struct PutBlockMessage {
-	/// Hash of the block
-	pub hash: Hash,
+pub enum BlockData {
+	Plain(#[serde(with = "serde_bytes")] Vec<u8>),
+	Compressed(#[serde(with = "serde_bytes")] Vec<u8>),
+}
 
-	/// Content of the block
-	#[serde(with = "serde_bytes")]
-	pub data: Vec<u8>,
+impl BlockData {
+	pub fn is_compressed(&self) -> bool {
+		match self {
+			BlockData::Plain(_) => false,
+			BlockData::Compressed(_) => true,
+		}
+	}
+
+	pub fn buffer(&self) -> &Vec<u8> {
+		match self {
+			BlockData::Plain(b) => b,
+			BlockData::Compressed(b) => b,
+		}
+	}
 }
 
 impl RpcMessage for Message {}
@@ -134,7 +150,7 @@ impl BlockManager {
 
 	async fn handle(self: Arc<Self>, msg: &Message) -> Result<Message, Error> {
 		match msg {
-			Message::PutBlock(m) => self.write_block(&m.hash, &m.data).await,
+			Message::PutBlock { hash, data } => self.write_block(&hash, &data).await,
 			Message::GetBlock(h) => self.read_block(h).await,
 			Message::NeedBlockQuery(h) => self.need_block(h).await.map(Message::NeedBlockReply),
 			_ => Err(Error::BadRPC(format!("Unexpected RPC message"))),
@@ -157,54 +173,96 @@ impl BlockManager {
 	}
 
 	/// Write a block to disk
-	async fn write_block(&self, hash: &Hash, data: &[u8]) -> Result<Message, Error> {
+	pub async fn write_block(&self, hash: &Hash, data: &BlockData) -> Result<Message, Error> {
+		let mut path = self.block_dir(hash);
+
 		let _lock = self.data_dir_lock.lock().await;
 
-		let mut path = self.block_dir(hash);
-		fs::create_dir_all(&path).await?;
+		let clean_plain = match self.is_block_compressed(hash).await {
+			Ok(true) => return Ok(Message::Ok),
+			Ok(false) if !data.is_compressed() => return Ok(Message::Ok), // we have a plain block, and the provided block is not compressed either
+			Ok(false) => true,
+			Err(_) => false,
+		};
 
+		fs::create_dir_all(&path).await?;
 		path.push(hex::encode(hash));
-		if fs::metadata(&path).await.is_ok() {
-			return Ok(Message::Ok);
+
+		if data.is_compressed() {
+			path.set_extension("zst");
 		}
 
-		let mut f = fs::File::create(path).await?;
-		f.write_all(data).await?;
+		let buffer = data.buffer();
+
+		let mut f = fs::File::create(path.clone()).await?;
+		f.write_all(&buffer).await?;
+
+		if clean_plain {
+			path.set_extension("");
+			fs::remove_file(path).await?;
+		}
 		drop(f);
 
 		Ok(Message::Ok)
 	}
 
 	/// Read block from disk, verifying it's integrity
-	async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
-		let path = self.block_path(hash);
+	pub async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
+		let mut path = self.block_path(hash);
 
-		let mut f = match fs::File::open(&path).await {
-			Ok(f) => f,
-			Err(e) => {
+		let mut data = vec![];
+		let block = match self.is_block_compressed(hash).await {
+			Ok(false) => {
+				let f = fs::File::open(&path).await;
+				f.map(|f| (f, false)).map_err(Into::into)
+			}
+			Ok(true) => {
+				path.set_extension("zst");
+				let f = fs::File::open(&path).await;
+				f.map(|f| (f, true)).map_err(Into::into)
+			}
+			Err(e) => Err(e),
+		};
+		let (mut f, compressed) = match block {
+			Ok(ok) => ok,
+			e => {
 				// Not found but maybe we should have had it ??
 				self.put_to_resync(hash, Duration::from_millis(0))?;
-				return Err(Into::into(e));
+				e?
 			}
 		};
-		let mut data = vec![];
 		f.read_to_end(&mut data).await?;
 		drop(f);
 
-		if blake2sum(&data[..]) != *hash {
+		let sum_ok = if compressed {
+			zstd_check_checksum(&data[..])
+		} else {
+			blake2sum(&data[..]) == *hash
+		};
+		if !sum_ok {
 			let _lock = self.data_dir_lock.lock().await;
 			warn!(
 				"Block {:?} is corrupted. Renaming to .corrupted and resyncing.",
 				hash
 			);
 			let mut path2 = path.clone();
-			path2.set_extension(".corrupted");
+			path2.set_extension("corrupted");
 			fs::rename(path, path2).await?;
 			self.put_to_resync(&hash, Duration::from_millis(0))?;
 			return Err(Error::CorruptData(*hash));
 		}
 
-		Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data }))
+		if compressed {
+			Ok(Message::PutBlock {
+				hash: *hash,
+				data: BlockData::Compressed(data),
+			})
+		} else {
+			Ok(Message::PutBlock {
+				hash: *hash,
+				data: BlockData::Plain(data),
+			})
+		}
 	}
 
 	/// Check if this node should have a block, but don't actually have it
@@ -215,14 +273,23 @@ impl BlockManager {
 			.map(|x| u64_from_be_bytes(x) > 0)
 			.unwrap_or(false);
 		if needed {
-			let path = self.block_path(hash);
-			let exists = fs::metadata(&path).await.is_ok();
+			let exists = self.is_block_compressed(hash).await.is_ok();
 			Ok(!exists)
 		} else {
 			Ok(false)
 		}
 	}
 
+	async fn is_block_compressed(&self, hash: &Hash) -> Result<bool, Error> {
+		let mut path = self.block_path(hash);
+		path.set_extension("zst");
+		if fs::metadata(&path).await.is_ok() {
+			return Ok(true);
+		}
+		path.set_extension("");
+		fs::metadata(&path).await.map(|_| false).map_err(Into::into)
+	}
+
 	fn block_dir(&self, hash: &Hash) -> PathBuf {
 		let mut path = self.data_dir.clone();
 		path.push(hex::encode(&hash.as_slice()[0..1]));
@@ -323,7 +390,7 @@ impl BlockManager {
 
 		let path = self.block_path(hash);
 
-		let exists = fs::metadata(&path).await.is_ok();
+		let exists = self.is_block_compressed(hash).await.is_ok();
 		let needed = self
 			.rc
 			.get(hash.as_ref())?
@@ -402,15 +469,14 @@ impl BlockManager {
 			// TODO find a way to not do this if they are sending it to us
 			// Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay
 			// between the RC being incremented and this part being called.
-			let block_data = self.rpc_get_block(&hash).await?;
-			self.write_block(hash, &block_data[..]).await?;
+			let block = self.rpc_get_raw_block(&hash).await?;
+			self.write_block(hash, &block).await?;
 		}
 
 		Ok(())
 	}
 
-	/// Ask nodes that might have a block for it
-	pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+	async fn rpc_get_raw_block(&self, hash: &Hash) -> Result<BlockData, Error> {
 		let who = self.replication.read_nodes(&hash);
 		let resps = self
 			.rpc_client
@@ -424,8 +490,9 @@ impl BlockManager {
 			.await?;
 
 		for resp in resps {
-			if let Message::PutBlock(msg) = resp {
-				return Ok(msg.data);
+			match resp {
+				Message::PutBlock { data, .. } => return Ok(data),
+				_ => {}
 			}
 		}
 		Err(Error::Message(format!(
@@ -434,13 +501,38 @@ impl BlockManager {
 		)))
 	}
 
+	/// Ask nodes that might have a block for it
+	pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+		self.rpc_get_raw_block(hash)
+			.await
+			.and_then(|data| match data {
+				BlockData::Plain(data) => Ok(data),
+				BlockData::Compressed(data) => {
+					zstd_decode(&data[..]).map_err(|_| Error::CorruptData(*hash))
+				}
+			})
+	}
+
 	/// Send block to nodes that should have it
 	pub async fn rpc_put_block(&self, hash: Hash, data: Vec<u8>) -> Result<(), Error> {
+		let garage = self.garage.load_full().unwrap();
+		let compressed = zstd_encode(&data[..], garage.config.compression_level);
+		let message = if compressed.is_ok() && compressed.as_ref().unwrap().len() < data.len() {
+			Message::PutBlock {
+				hash,
+				data: BlockData::Compressed(compressed.unwrap()),
+			}
+		} else {
+			Message::PutBlock {
+				hash,
+				data: BlockData::Plain(data),
+			}
+		};
 		let who = self.replication.write_nodes(&hash);
 		self.rpc_client
 			.try_call_many(
 				&who[..],
-				Message::PutBlock(PutBlockMessage { hash, data }),
+				message,
 				RequestStrategy::with_quorum(self.replication.write_quorum())
 					.with_timeout(BLOCK_RW_TIMEOUT),
 			)
@@ -537,3 +629,16 @@ fn u64_from_be_bytes<T: AsRef<[u8]>>(bytes: T) -> u64 {
 	x8.copy_from_slice(bytes.as_ref());
 	u64::from_be_bytes(x8)
 }
+
+fn zstd_check_checksum<R: std::io::Read>(source: R) -> bool {
+	zstd::stream::copy_decode(source, std::io::sink()).is_ok()
+}
+
+fn zstd_encode<R: std::io::Read>(mut source: R, level: i32) -> std::io::Result<Vec<u8>> {
+	let mut result = Vec::<u8>::new();
+	let mut encoder = Encoder::new(&mut result, level)?;
+	encoder.include_checksum(true)?;
+	std::io::copy(&mut source, &mut encoder)?;
+	encoder.finish()?;
+	Ok(result)
+}
diff --git a/src/util/config.rs b/src/util/config.rs
index bb70467b..29901d46 100644
--- a/src/util/config.rs
+++ b/src/util/config.rs
@@ -45,6 +45,10 @@ pub struct Config {
 	#[serde(default = "default_replication_factor")]
 	pub data_replication_factor: usize,
 
+	/// Zstd compression level used on data blocks
+	#[serde(default)]
+	pub compression_level: i32,
+
 	/// Configuration for RPC TLS
 	pub rpc_tls: Option<TlsConfig>,