diff --git a/lib/asciinema/asciicasts.ex b/lib/asciinema/asciicasts.ex
index 842c783..0966a93 100644
--- a/lib/asciinema/asciicasts.ex
+++ b/lib/asciinema/asciicasts.ex
@@ -28,7 +28,7 @@ defmodule Asciinema.Asciicasts do
                            file: filename,
                            private: user.asciicasts_private_by_default}
 
-    files = [{:file, upload}]
+    files = [{:file, upload, true}]
 
     with {:ok, json} <- File.read(path),
          {:ok, attrs} <- Poison.decode(json),
@@ -58,7 +58,7 @@ defmodule Asciinema.Asciicasts do
     attrs = Map.merge(attrs, overrides)
     attrs = if attrs[:uname], do: Map.drop(attrs, [:user_agent]), else: attrs
     changeset = Asciicast.create_changeset(asciicast, attrs)
-    files = [{:stdout_data, data}, {:stdout_timing, timing}]
+    files = [{:stdout_data, data, false}, {:stdout_timing, timing, false}]
 
     case do_create_asciicast(changeset, files) do
       {:ok, %Asciicast{} = asciicast} ->
@@ -103,7 +103,7 @@ defmodule Asciinema.Asciicasts do
     {_, result} = Repo.transaction(fn ->
       case Repo.insert(changeset) do
         {:ok, %Asciicast{} = asciicast} ->
-          Enum.each(files, fn {type, upload} -> save_file(asciicast, type, upload) end)
+          Enum.each(files, &save_file(asciicast, &1))
           {:ok, asciicast}
         otherwise ->
           otherwise
@@ -113,9 +113,9 @@ defmodule Asciinema.Asciicasts do
     result
   end
 
-  defp save_file(asciicast, type, %{path: tmp_file_path, content_type: content_type}) do
+  defp save_file(asciicast, {type, %{path: tmp_path, content_type: content_type}, compress}) do
     file_store_path = Asciicast.file_store_path(asciicast, type)
-    :ok = FileStore.put_file(file_store_path, tmp_file_path, content_type)
+    :ok = FileStore.put_file(file_store_path, tmp_path, content_type, compress)
   end
 
   def stdout_stream(%Asciicast{version: 0} = asciicast) do
diff --git a/lib/asciinema/file_store.ex b/lib/asciinema/file_store.ex
index 0105ca2..32ea779 100644
--- a/lib/asciinema/file_store.ex
+++ b/lib/asciinema/file_store.ex
@@ -1,6 +1,6 @@
 defmodule Asciinema.FileStore do
   @doc "Puts file at given path in store"
-  @callback put_file(dst_path :: String.t, src_local_path :: String.t, content_type :: String.t) :: :ok | {:error, term}
+  @callback put_file(dst_path :: String.t, src_local_path :: String.t, content_type :: String.t, compress :: boolean) :: :ok | {:error, term}
 
   @doc "Serves file at given path in store"
   @callback serve_file(conn :: %Plug.Conn{}, path :: String.t, filename :: String.t) :: %Plug.Conn{}
@@ -29,8 +29,8 @@ defmodule Asciinema.FileStore do
 
   # Shortcuts
 
-  def put_file(dst_path, src_local_path, content_type) do
-    instance().put_file(dst_path, src_local_path, content_type)
+  def put_file(dst_path, src_local_path, content_type, compress \\ false) do
+    instance().put_file(dst_path, src_local_path, content_type, compress)
   end
 
   def open_file(path, f) do
diff --git a/lib/asciinema/file_store/cached.ex b/lib/asciinema/file_store/cached.ex
index e614a0b..fd92598 100644
--- a/lib/asciinema/file_store/cached.ex
+++ b/lib/asciinema/file_store/cached.ex
@@ -2,9 +2,9 @@ defmodule Asciinema.FileStore.Cached do
   use Asciinema.FileStore
   alias Plug.MIME
 
-  def put_file(dst_path, src_local_path, content_type) do
-    with :ok <- remote_store().put_file(dst_path, src_local_path, content_type),
-         :ok <- cache_store().put_file(dst_path, src_local_path, content_type) do
+  def put_file(dst_path, src_local_path, content_type, compress \\ false) do
+    with :ok <- remote_store().put_file(dst_path, src_local_path, content_type, compress),
+         :ok <- cache_store().put_file(dst_path, src_local_path, content_type, compress) do
       :ok
     else
       otherwise -> otherwise
diff --git a/lib/asciinema/file_store/local.ex b/lib/asciinema/file_store/local.ex
index 447ab1c..040ca2a 100644
--- a/lib/asciinema/file_store/local.ex
+++ b/lib/asciinema/file_store/local.ex
@@ -3,7 +3,7 @@ defmodule Asciinema.FileStore.Local do
   import Plug.Conn
   alias Plug.MIME
 
-  def put_file(dst_path, src_local_path, _content_type) do
+  def put_file(dst_path, src_local_path, _content_type, _compress \\ false) do
     full_dst_path = base_path() <> dst_path
     parent_dir = Path.dirname(full_dst_path)
 
diff --git a/lib/asciinema/file_store/s3.ex b/lib/asciinema/file_store/s3.ex
index bff6b55..8cef4fb 100644
--- a/lib/asciinema/file_store/s3.ex
+++ b/lib/asciinema/file_store/s3.ex
@@ -3,9 +3,16 @@ defmodule Asciinema.FileStore.S3 do
   import Phoenix.Controller, only: [redirect: 2]
   alias ExAws.S3
 
-  def put_file(dst_path, src_local_path, content_type) do
-    body = File.read!(src_local_path)
-    opts = [{:content_type, content_type}]
+  def put_file(dst_path, src_local_path, content_type, compress \\ false) do
+    {body, opts} = if compress do
+      body = File.read!(src_local_path) |> :zlib.gzip
+      opts = [{:content_type, content_type}, {:content_encoding, "gzip"}]
+      {body, opts}
+    else
+      body = File.read!(src_local_path)
+      opts = [{:content_type, content_type}]
+      {body, opts}
+    end
 
     case make_request(S3.put_object(bucket(), base_path() <> dst_path, body, opts)) do
       {:ok, _} -> :ok
@@ -33,7 +40,13 @@ defmodule Asciinema.FileStore.S3 do
     response = S3.get_object(bucket(), base_path() <> path) |> make_request
 
     case response do
-      {:ok, %{body: body}} ->
+      {:ok, %{headers: headers, body: body}} ->
+        body =
+          case List.keyfind(headers, "Content-Encoding", 0) do
+            {"Content-Encoding", "gzip"} -> :zlib.gunzip(body)
+            _ -> body
+          end
+
         if function do
           File.open(body, [:ram, :binary, :read], function)
         else