diff --git a/bench/Main.hs b/bench/Main.hs
new file mode 100644
index 000000000..885744ca1
--- /dev/null
+++ b/bench/Main.hs
@@ -0,0 +1,235 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Main (main) where
+
+import Data.Int
+import Data.Proxy
+import Data.Typeable
+import Data.Word
+import Foreign.C.Types
+import Gauge.Main
+
+import System.Random
+
+main :: IO ()
+main = do
+  let !sz = 100000
+  defaultMain
+    [ bgroup "pure"
+      [ bgroup "random"
+        [ pureRandomBench (Proxy :: Proxy Float) sz
+        , pureRandomBench (Proxy :: Proxy Double) sz
+        , pureRandomBench (Proxy :: Proxy Integer) sz
+        , pureRandomBench (Proxy :: Proxy Word8) sz
+        , pureRandomBench (Proxy :: Proxy Word16) sz
+        , pureRandomBench (Proxy :: Proxy Word32) sz
+        , pureRandomBench (Proxy :: Proxy Word64) sz
+        , pureRandomBench (Proxy :: Proxy Word) sz
+        , pureRandomBench (Proxy :: Proxy Int8) sz
+        , pureRandomBench (Proxy :: Proxy Int16) sz
+        , pureRandomBench (Proxy :: Proxy Int32) sz
+        , pureRandomBench (Proxy :: Proxy Int64) sz
+        , pureRandomBench (Proxy :: Proxy Int) sz
+        , pureRandomBench (Proxy :: Proxy Char) sz
+        , pureRandomBench (Proxy :: Proxy Bool) sz
+        -- , pureRandomBench (Proxy :: Proxy CBool) sz
+        , pureRandomBench (Proxy :: Proxy CChar) sz
+        , pureRandomBench (Proxy :: Proxy CSChar) sz
+        , pureRandomBench (Proxy :: Proxy CUChar) sz
+        , pureRandomBench (Proxy :: Proxy CShort) sz
+        , pureRandomBench (Proxy :: Proxy CUShort) sz
+        , pureRandomBench (Proxy :: Proxy CInt) sz
+        , pureRandomBench (Proxy :: Proxy CUInt) sz
+        , pureRandomBench (Proxy :: Proxy CLong) sz
+        , pureRandomBench (Proxy :: Proxy CULong) sz
+        , pureRandomBench (Proxy :: Proxy CPtrdiff) sz
+        , pureRandomBench (Proxy :: Proxy CSize) sz
+        , pureRandomBench (Proxy :: Proxy CWchar) sz
+        , pureRandomBench (Proxy :: Proxy CSigAtomic) sz
+        , pureRandomBench (Proxy :: Proxy CLLong) sz
+        , pureRandomBench (Proxy :: Proxy CULLong) sz
+        , pureRandomBench (Proxy :: Proxy CIntPtr) sz
+        , pureRandomBench (Proxy :: Proxy CUIntPtr) sz
+        , pureRandomBench (Proxy :: Proxy CIntMax) sz
+        , pureRandomBench (Proxy :: Proxy CUIntMax) sz
+        ]
+      , bgroup "randomR"
+        [ bgroup "full"
+          [ pureUniformRFullBench (Proxy :: Proxy Word8) sz
+          , pureUniformRFullBench (Proxy :: Proxy Word16) sz
+          , pureUniformRFullBench (Proxy :: Proxy Word32) sz
+          , pureUniformRFullBench (Proxy :: Proxy Word64) sz
+          , pureUniformRFullBench (Proxy :: Proxy Word) sz
+          , pureUniformRFullBench (Proxy :: Proxy Int8) sz
+          , pureUniformRFullBench (Proxy :: Proxy Int16) sz
+          , pureUniformRFullBench (Proxy :: Proxy Int32) sz
+          , pureUniformRFullBench (Proxy :: Proxy Int64) sz
+          , pureUniformRFullBench (Proxy :: Proxy Int) sz
+          , pureUniformRFullBench (Proxy :: Proxy Char) sz
+          , pureUniformRFullBench (Proxy :: Proxy Bool) sz
+          -- , pureUniformRFullBench (Proxy :: Proxy CBool) sz
+          , pureUniformRFullBench (Proxy :: Proxy CChar) sz
+          , pureUniformRFullBench (Proxy :: Proxy CSChar) sz
+          , pureUniformRFullBench (Proxy :: Proxy CUChar) sz
+          , pureUniformRFullBench (Proxy :: Proxy CShort) sz
+          , pureUniformRFullBench (Proxy :: Proxy CUShort) sz
+          , pureUniformRFullBench (Proxy :: Proxy CInt) sz
+          , pureUniformRFullBench (Proxy :: Proxy CUInt) sz
+          , pureUniformRFullBench (Proxy :: Proxy CLong) sz
+          , pureUniformRFullBench (Proxy :: Proxy CULong) sz
+          , pureUniformRFullBench (Proxy :: Proxy CPtrdiff) sz
+          , pureUniformRFullBench (Proxy :: Proxy CSize) sz
+          , pureUniformRFullBench (Proxy :: Proxy CWchar) sz
+          , pureUniformRFullBench (Proxy :: Proxy CSigAtomic) sz
+          , pureUniformRFullBench (Proxy :: Proxy CLLong) sz
+          , pureUniformRFullBench (Proxy :: Proxy CULLong) sz
+          , pureUniformRFullBench (Proxy :: Proxy CIntPtr) sz
+          , pureUniformRFullBench (Proxy :: Proxy CUIntPtr) sz
+          , pureUniformRFullBench (Proxy :: Proxy CIntMax) sz
+          , pureUniformRFullBench (Proxy :: Proxy CUIntMax) sz
+          ]
+        , bgroup "excludeMax"
+          [ pureUniformRExcludeMaxBench (Proxy :: Proxy Word8) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Word16) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Word32) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Word64) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Word) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Int8) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Int16) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Int32) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Int64) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Int) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Char) sz
+          -- , pureUniformRExcludeMaxBench (Proxy :: Proxy CBool) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy Bool) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CChar) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CSChar) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CUChar) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CShort) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CUShort) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CInt) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CUInt) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CLong) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CULong) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CPtrdiff) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CSize) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CWchar) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CSigAtomic) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CLLong) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CULLong) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CIntPtr) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CUIntPtr) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CIntMax) sz
+          , pureUniformRExcludeMaxBench (Proxy :: Proxy CUIntMax) sz
+          ]
+        , bgroup "includeHalf"
+          [ pureUniformRIncludeHalfBench (Proxy :: Proxy Word8) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Word16) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Word32) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Word64) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Word) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Int8) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Int16) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Int32) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Int64) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy Int) sz
+          , pureUniformRIncludeHalfEnumBench (Proxy :: Proxy Char) sz
+          -- , pureUniformRIncludeHalfEnumBench (Proxy :: Proxy CBool) sz
+          , pureUniformRIncludeHalfEnumBench (Proxy :: Proxy Bool) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CChar) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CSChar) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CUChar) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CShort) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CUShort) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CInt) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CUInt) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CLong) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CULong) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CPtrdiff) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CSize) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CWchar) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CSigAtomic) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CLLong) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CULLong) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CIntPtr) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CUIntPtr) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CIntMax) sz
+          , pureUniformRIncludeHalfBench (Proxy :: Proxy CUIntMax) sz
+          ]
+        , bgroup "unbounded"
+          [ pureUniformRBench (Proxy :: Proxy Float) (1.23e-4, 5.67e8) sz
+          , pureUniformRBench (Proxy :: Proxy Double) (1.23e-4, 5.67e8) sz
+          , let !i = (10 :: Integer) ^ (100 :: Integer)
+                !range = (-i - 1, i + 1)
+            in pureUniformRBench (Proxy :: Proxy Integer) range sz
+          -- , let !n = (10 :: Natural) ^ (100 :: Natural)
+          --       !range = (1, n - 1)
+          --   in pureUniformRBench (Proxy :: Proxy Natural) range sz
+          ]
+        ]
+      ]
+    ]
+
+pureRandomBench :: forall a. (Typeable a, Random a) => Proxy a -> Int -> Benchmark
+pureRandomBench px =
+  let !stdGen = mkStdGen 1337
+   in pureBench px (genMany (random :: StdGen -> (a, StdGen)) stdGen)
+
+pureUniformRFullBench ::
+     forall a. (Typeable a, Random a, Bounded a)
+  => Proxy a
+  -> Int
+  -> Benchmark
+pureUniformRFullBench px =
+  let range = (minBound :: a, maxBound :: a)
+   in pureUniformRBench px range
+
+pureUniformRExcludeMaxBench ::
+     forall a. (Typeable a, Random a, Bounded a, Enum a)
+  => Proxy a
+  -> Int
+  -> Benchmark
+pureUniformRExcludeMaxBench px =
+  let range = (minBound :: a, pred (maxBound :: a))
+   in pureUniformRBench px range
+
+pureUniformRIncludeHalfBench ::
+     forall a. (Typeable a, Random a, Bounded a, Integral a)
+  => Proxy a
+  -> Int
+  -> Benchmark
+pureUniformRIncludeHalfBench px =
+  let range = ((minBound :: a) + 1, ((maxBound :: a) `div` 2) + 1)
+  in pureUniformRBench px range
+
+pureUniformRIncludeHalfEnumBench ::
+     forall a. (Typeable a, Random a, Bounded a, Enum a)
+  => Proxy a
+  -> Int
+  -> Benchmark
+pureUniformRIncludeHalfEnumBench px =
+  let range = (succ (minBound :: a), toEnum ((fromEnum (maxBound :: a) `div` 2) + 1))
+  in pureUniformRBench px range
+
+pureUniformRBench ::
+     forall a. (Typeable a, Random a)
+  => Proxy a
+  -> (a, a)
+  -> Int
+  -> Benchmark
+pureUniformRBench px range@(!_, !_) =
+  let !stdGen = mkStdGen 1337
+  in pureBench px (genMany (randomR range) stdGen)
+
+pureBench :: forall a. (Typeable a) => Proxy a -> (Int -> ()) -> Int -> Benchmark
+pureBench px f sz = bench (showsTypeRep (typeRep px) "") $ nf f sz
+
+genMany :: (g -> (a, g)) -> g -> Int -> ()
+genMany f g0 n = go g0 0
+  where
+    go g i
+      | i < n =
+        case f g of
+          (x, g') -> x `seq` go g' (i + 1)
+      | otherwise = g `seq` ()
diff --git a/random.cabal b/random.cabal
index fd29840fb..ec5304eca 100644
--- a/random.cabal
+++ b/random.cabal
@@ -68,3 +68,13 @@ Test-Suite TestRandomIOs
     hs-source-dirs: tests
     build-depends:  base >= 3 && < 5, random
     ghc-options:    -rtsopts -O2
+
+benchmark bench
+    type:           exitcode-stdio-1.0
+    main-is:        Main.hs
+    hs-source-dirs: bench
+    ghc-options:    -Wall -O2
+    build-depends:
+        base >=4.10 && <5,
+        gauge >=0.2.3 && <0.3,
+        random -any
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
index 000000000..31df520b7
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,4 @@
+resolver: lts-15.1
+packages:
+- .
+extra-deps: []