diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,7 @@
 # Unreleased
 
+* Add interceptors for setting the log level.
+
 # 0.3.0.0
 
 * Add concurrent interpreters for stdout and stderr.
diff --git a/lib/Polysemy/Log.hs b/lib/Polysemy/Log.hs
--- a/lib/Polysemy/Log.hs
+++ b/lib/Polysemy/Log.hs
@@ -33,15 +33,23 @@
   crit,
   formatLogEntry,
   Severity(..),
+  setLogLevel,
+  setLogLevelWith,
 
   -- ** Interpreters
   interpretLogStderrWith,
+  interpretLogStderrLevelWith,
   interpretLogStderrConc,
+  interpretLogStderrLevelConc,
   interpretLogStderr,
+  interpretLogStderrLevel,
   interpretLogStderr',
   interpretLogStdoutWith,
+  interpretLogStdoutLevelWith,
   interpretLogStdoutConc,
+  interpretLogStdoutLevelConc,
   interpretLogStdout,
+  interpretLogStdoutLevel,
   interpretLogStdout',
   interpretLogDataLog,
   interpretLogDataLog',
@@ -63,6 +71,7 @@
 import Polysemy.Log.Data.LogMessage (LogMessage (LogMessage))
 import Polysemy.Log.Data.Severity (Severity (..))
 import Polysemy.Log.Format (formatLogEntry)
+import Polysemy.Log.Level (setLogLevel, setLogLevelWith)
 import Polysemy.Log.Log (
   interpretLogDataLog,
   interpretLogDataLog',
@@ -75,6 +84,9 @@
   interpretLogStderr,
   interpretLogStderr',
   interpretLogStderrConc,
+  interpretLogStderrLevel,
+  interpretLogStderrLevelConc,
+  interpretLogStderrLevelWith,
   interpretLogStderrWith,
   )
 import Polysemy.Log.Stdout (
@@ -83,6 +95,9 @@
   interpretLogStdout,
   interpretLogStdout',
   interpretLogStdoutConc,
+  interpretLogStdoutLevel,
+  interpretLogStdoutLevelConc,
+  interpretLogStdoutLevelWith,
   interpretLogStdoutWith,
   )
 
@@ -93,10 +108,10 @@
 --
 -- /polysemy-log/ provides an abstraction for this task with interpreter adapters for
 -- [co-log](https://hackage.haskell.org/package/co-log-polysemy) and
--- [di](https://hackage.haskell.org/package/di-polysemy).
+-- [di](https://hackage.haskell.org/package/di-polysemy), but the library can be used without those as well.
 --
--- If you're looking for instructions on how to use /polysemy-log/ with a backend, please visit the haddocks of the
--- adapter libraries:
+-- If you're looking for instructions on how to use /polysemy-log/ with a third-party backend, please visit the haddocks
+-- of the adapter libraries:
 --
 --  - [polysemy-log-co for co-log](https://hackage.haskell.org/package/polysemy-log-co)
 --  - [polysemy-log-di for di](https://hackage.haskell.org/package/polysemy-log-di)
@@ -127,7 +142,7 @@
 
 -- $messages
 -- While it would be quite reasonable to handle any kind of complexly structured logging data ergonomically with
--- /polysemy/, most authors probably prefer not to burden their users with this task while still appreciating the
+-- /Polysemy/, most authors probably prefer not to burden their users with this task while still appreciating the
 -- possibility to easily relay debug information in a standardized way.
 --
 -- The default logging effect uses a simple data structure that annotates the given severity and text message with the
diff --git a/lib/Polysemy/Log/Atomic.hs b/lib/Polysemy/Log/Atomic.hs
--- a/lib/Polysemy/Log/Atomic.hs
+++ b/lib/Polysemy/Log/Atomic.hs
@@ -15,7 +15,7 @@
   InterpreterFor (DataLog a) r
 interpretDataLogAtomic' =
   interpretDataLog \ msg -> atomicModify' @[a] (msg :)
-{-# INLINE interpretDataLogAtomic' #-}
+{-# inline interpretDataLogAtomic' #-}
 
 -- |Interpret 'DataLog' by prepending each message to a list in an 'AtomicState', then interpret the 'AtomicState' in a
 -- 'TVar'.
@@ -26,7 +26,7 @@
 interpretDataLogAtomic sem = do
   tv <- newTVarIO []
   runAtomicStateTVar tv (interpretDataLogAtomic' sem)
-{-# INLINE interpretDataLogAtomic #-}
+{-# inline interpretDataLogAtomic #-}
 
 -- |Interpret 'Log' by prepending each message to a list in an 'AtomicState'.
 interpretLogAtomic' ::
@@ -35,7 +35,7 @@
 interpretLogAtomic' =
   interpret \case
     Log msg -> atomicModify' (msg :)
-{-# INLINE interpretLogAtomic' #-}
+{-# inline interpretLogAtomic' #-}
 
 -- |Interpret 'Log' by prepending each message to a list in an 'AtomicState', then interpret the 'AtomicState' in a
 -- 'TVar'.
@@ -45,4 +45,4 @@
 interpretLogAtomic sem = do
   tv <- newTVarIO []
   runAtomicStateTVar tv (interpretLogAtomic' sem)
-{-# INLINE interpretLogAtomic #-}
+{-# inline interpretLogAtomic #-}
diff --git a/lib/Polysemy/Log/Conc.hs b/lib/Polysemy/Log/Conc.hs
--- a/lib/Polysemy/Log/Conc.hs
+++ b/lib/Polysemy/Log/Conc.hs
@@ -27,7 +27,7 @@
       liftT (Queue.write (context msg))
     Local f ma ->
       raise . interceptDataLogConcWithLocal (f . context) . subsume =<< runT ma
-{-# INLINE interceptDataLogConcWithLocal #-}
+{-# inline interceptDataLogConcWithLocal #-}
 
 -- |Intercept 'DataLog' for concurrent processing.
 interceptDataLogConcWith ::
@@ -37,7 +37,7 @@
   Sem r a
 interceptDataLogConcWith =
   interceptDataLogConcWithLocal @msg id
-{-# INLINE interceptDataLogConcWith #-}
+{-# inline interceptDataLogConcWith #-}
 
 -- |Part of 'interceptDataLogConc'.
 -- Loop as long as the proided queue is open and relay all dequeued messages to the ultimate interpreter, thereby
@@ -76,4 +76,4 @@
   interpretQueueTBM @msg maxQueued do
     !_ <- async (loggerThread @msg)
     interceptDataLogConcWith @msg (raise sem)
-{-# INLINE interceptDataLogConc #-}
+{-# inline interceptDataLogConc #-}
diff --git a/lib/Polysemy/Log/Data/Log.hs b/lib/Polysemy/Log/Data/Log.hs
--- a/lib/Polysemy/Log/Data/Log.hs
+++ b/lib/Polysemy/Log/Data/Log.hs
@@ -33,7 +33,7 @@
 log severity message =
   withFrozenCallStack $
   send (Log (LogMessage severity message))
-{-# INLINE log #-}
+{-# inline log #-}
 
 -- |Log a message with the 'Trace' severity.
 trace ::
@@ -44,7 +44,7 @@
 trace =
   withFrozenCallStack $
   log Trace
-{-# INLINE trace #-}
+{-# inline trace #-}
 
 -- |Log a message with the 'Debug' severity.
 debug ::
@@ -55,7 +55,7 @@
 debug =
   withFrozenCallStack $
   log Debug
-{-# INLINE debug #-}
+{-# inline debug #-}
 
 -- |Log a message with the 'Info' severity.
 info ::
@@ -66,7 +66,7 @@
 info =
   withFrozenCallStack $
   log Info
-{-# INLINE info #-}
+{-# inline info #-}
 
 -- |Log a message with the 'Warn' severity.
 warn ::
@@ -77,7 +77,7 @@
 warn =
   withFrozenCallStack $
   log Warn
-{-# INLINE warn #-}
+{-# inline warn #-}
 
 -- |Log a message with the 'Error' severity.
 error ::
@@ -88,7 +88,7 @@
 error =
   withFrozenCallStack $
   log Error
-{-# INLINE error #-}
+{-# inline error #-}
 
 -- |Log a message with the 'Crit' severity.
 crit ::
@@ -99,4 +99,4 @@
 crit =
   withFrozenCallStack $
   log Crit
-{-# INLINE crit #-}
+{-# inline crit #-}
diff --git a/lib/Polysemy/Log/Data/Severity.hs b/lib/Polysemy/Log/Data/Severity.hs
--- a/lib/Polysemy/Log/Data/Severity.hs
+++ b/lib/Polysemy/Log/Data/Severity.hs
@@ -14,4 +14,4 @@
   Error
   |
   Crit
-  deriving (Eq, Show, Enum)
+  deriving (Eq, Show, Enum, Ord)
diff --git a/lib/Polysemy/Log/Format.hs b/lib/Polysemy/Log/Format.hs
--- a/lib/Polysemy/Log/Format.hs
+++ b/lib/Polysemy/Log/Format.hs
@@ -2,13 +2,13 @@
 module Polysemy.Log.Format where
 
 import qualified Data.Text as Text
-import GHC.Exception (SrcLoc(..))
-import System.Console.ANSI (Color(..), ColorIntensity(Dull), ConsoleLayer(Foreground), SGR (..), setSGRCode)
+import GHC.Exception (SrcLoc (..))
+import System.Console.ANSI (Color (..), ColorIntensity (Dull), ConsoleLayer (Foreground), SGR (..), setSGRCode)
 
-import Polysemy.Log.Data.LogEntry (LogEntry(LogEntry))
+import Polysemy.Log.Data.LogEntry (LogEntry (LogEntry))
 import qualified Polysemy.Log.Data.LogMessage as LogMessage
-import Polysemy.Log.Data.LogMessage (LogMessage(LogMessage))
-import Polysemy.Log.Data.Severity (Severity(..))
+import Polysemy.Log.Data.LogMessage (LogMessage (LogMessage))
+import Polysemy.Log.Data.Severity (Severity (..))
 
 -- |Create a colored tag with the format @"[tag]"@ for a 'Severity' value.
 formatSeverity :: Severity -> Text
@@ -41,9 +41,9 @@
   maybe "<unknown loc>" format . listToMaybe . getCallStack
   where
     format (_, SrcLoc {..}) =
-      [qt|#{shortModule (toText srcLocModule)}\##{srcLocStartLine}|]
+      shortModule (toText srcLocModule) <> "#" <> show srcLocStartLine
 
 -- |Default formatter for the default message type.
 formatLogEntry :: LogEntry LogMessage -> Text
 formatLogEntry (LogEntry LogMessage {..} _ source) =
-  [qt|#{formatSeverity severity} [#{formatCaller source}] #{message}|]
+  formatSeverity severity <> " [" <> formatCaller source <> "] " <> message
diff --git a/lib/Polysemy/Log/Level.hs b/lib/Polysemy/Log/Level.hs
new file mode 100644
--- /dev/null
+++ b/lib/Polysemy/Log/Level.hs
@@ -0,0 +1,41 @@
+-- |Description: Internal
+module Polysemy.Log.Level where
+
+import Polysemy (interceptH, runTSimple)
+
+import qualified Polysemy.Log.Data.DataLog as DataLog
+import Polysemy.Log.Data.DataLog (DataLog (DataLog, Local))
+import qualified Polysemy.Log.Data.LogEntry as LogEntry
+import Polysemy.Log.Data.LogEntry (LogEntry)
+import qualified Polysemy.Log.Data.LogMessage as LogMessage
+import Polysemy.Log.Data.LogMessage (LogMessage)
+import Polysemy.Log.Data.Severity (Severity)
+
+-- |Set the minimum severity for messages to be handled, with 'Nothing' meaning no messages are logged.
+-- This can be used with arbitrary message types, using the @ex@ argument to extract the severity from the message.
+setLogLevelWith ::
+  ∀ msg r a .
+  Member (DataLog msg) r =>
+  (msg -> Severity) ->
+  Maybe Severity ->
+  Sem r a ->
+  Sem r a
+setLogLevelWith ex level =
+  interceptH @(DataLog msg) \case
+    DataLog msg -> do
+      when (maybe False (ex msg >=) level) do
+        DataLog.dataLog msg
+      pureT ()
+    Local f mb ->
+      DataLog.local f (runTSimple mb)
+{-# inline setLogLevelWith #-}
+
+-- |Set the minimum severity for messages to be handled, with 'Nothing' meaning no messages are logged.
+setLogLevel ::
+  Member (DataLog (LogEntry LogMessage)) r =>
+  Maybe Severity ->
+  Sem r a ->
+  Sem r a
+setLogLevel =
+  setLogLevelWith (LogMessage.severity . LogEntry.message)
+{-# inline setLogLevel #-}
diff --git a/lib/Polysemy/Log/Log.hs b/lib/Polysemy/Log/Log.hs
--- a/lib/Polysemy/Log/Log.hs
+++ b/lib/Polysemy/Log/Log.hs
@@ -23,7 +23,7 @@
 interpretLogLogMetadata =
   interpret \case
     Log msg -> annotated msg
-{-# INLINE interpretLogLogMetadata #-}
+{-# inline interpretLogLogMetadata #-}
 
 -- |Interpret the intermediate internal effect 'LogMetadata' into 'DataLog'.
 --
@@ -36,7 +36,7 @@
 interpretLogMetadataDataLog =
   interpret \case
     Annotated msg -> dataLog =<< annotate msg
-{-# INLINE interpretLogMetadataDataLog #-}
+{-# inline interpretLogMetadataDataLog #-}
 
 -- |Interpret the intermediate internal effect 'LogMetadata' into 'DataLog'.
 interpretLogMetadataDataLog' ::
@@ -44,7 +44,7 @@
   InterpretersFor [LogMetadata a, GhcTime] r
 interpretLogMetadataDataLog' =
   interpretTimeGhc . interpretLogMetadataDataLog
-{-# INLINE interpretLogMetadataDataLog' #-}
+{-# inline interpretLogMetadataDataLog' #-}
 
 -- |Interpret 'Log' into 'DataLog', adding metadata information and wrapping with 'LogEntry'.
 --
@@ -55,7 +55,7 @@
   InterpreterFor Log r
 interpretLogDataLog =
   interpretLogMetadataDataLog @LogMessage . interpretLogLogMetadata . raiseUnder
-{-# INLINE interpretLogDataLog #-}
+{-# inline interpretLogDataLog #-}
 
 -- |Interpret 'Log' into 'DataLog', adding metadata information and wrapping with 'LogEntry'.
 interpretLogDataLog' ::
@@ -63,7 +63,7 @@
   InterpretersFor [Log, LogMetadata LogMessage, GhcTime] r
 interpretLogDataLog' =
   interpretLogMetadataDataLog' . interpretLogLogMetadata
-{-# INLINE interpretLogDataLog' #-}
+{-# inline interpretLogDataLog' #-}
 
 -- |Interpret 'Log' into 'DataLog' concurrently, adding metadata information and wrapping with 'LogEntry'.
 interpretLogDataLogConc ::
@@ -76,7 +76,7 @@
   interpretLogMetadataDataLog @LogMessage .
   interpretLogLogMetadata .
   raiseUnder2
-{-# INLINE interpretLogDataLogConc #-}
+{-# inline interpretLogDataLogConc #-}
 
 -- |Helper for maintaining a context function as state that is applied to each logged message, allowing the context of a
 -- block to be modified.
@@ -91,7 +91,7 @@
       liftT (log (context msg))
     Local f ma ->
       raise . interpretDataLogLocal (f . context) log =<< runT ma
-{-# INLINE interpretDataLogLocal #-}
+{-# inline interpretDataLogLocal #-}
 
 -- |Combinator for building 'DataLog' interpreters that handles 'Local'.
 interpretDataLog ::
diff --git a/lib/Polysemy/Log/Prelude.hs b/lib/Polysemy/Log/Prelude.hs
--- a/lib/Polysemy/Log/Prelude.hs
+++ b/lib/Polysemy/Log/Prelude.hs
@@ -2,16 +2,13 @@
 {-# language NoImplicitPrelude #-}
 
 module Polysemy.Log.Prelude (
-  module Polysemy.Log.Prelude,
   module GHC.Err,
   module Polysemy,
   module Polysemy.AtomicState,
   module Relude,
 ) where
 
-import qualified Data.String.Interpolate as Interpolate
 import GHC.Err (undefined)
-import Language.Haskell.TH.Quote (QuasiQuoter)
 import Polysemy (
   Effect,
   EffectRow,
@@ -58,8 +55,3 @@
   traceShow,
   undefined,
   )
-
-qt :: QuasiQuoter
-qt =
-  Interpolate.i
-{-# INLINE qt #-}
diff --git a/lib/Polysemy/Log/Stderr.hs b/lib/Polysemy/Log/Stderr.hs
--- a/lib/Polysemy/Log/Stderr.hs
+++ b/lib/Polysemy/Log/Stderr.hs
@@ -11,7 +11,9 @@
 import Polysemy.Log.Data.Log (Log)
 import Polysemy.Log.Data.LogEntry (LogEntry)
 import Polysemy.Log.Data.LogMessage (LogMessage)
+import Polysemy.Log.Data.Severity (Severity)
 import Polysemy.Log.Format (formatLogEntry)
+import Polysemy.Log.Level (setLogLevel)
 import Polysemy.Log.Log (interpretDataLog, interpretLogDataLog, interpretLogDataLogConc)
 
 -- |Interpret 'DataLog' by printing to stderr, converting messages to 'Text' with the supplied function.
@@ -21,7 +23,7 @@
   InterpreterFor (DataLog a) r
 interpretDataLogStderrWith fmt =
   interpretDataLog \ msg -> embed (Text.hPutStrLn stderr (fmt msg))
-{-# INLINE interpretDataLogStderrWith #-}
+{-# inline interpretDataLogStderrWith #-}
 
 -- |Interpret 'DataLog' by printing to stderr, converting messages to 'Text' by using 'Show'.
 interpretDataLogStderr ::
@@ -30,7 +32,7 @@
   InterpreterFor (DataLog a) r
 interpretDataLogStderr =
   interpretDataLogStderrWith show
-{-# INLINE interpretDataLogStderr #-}
+{-# inline interpretDataLogStderr #-}
 
 -- |Interpret 'Log' by printing to stderr, converting messages to 'Text' with the supplied function.
 interpretLogStderrWith ::
@@ -42,8 +44,23 @@
   interpretTimeGhc .
   interpretLogDataLog .
   raiseUnder2
-{-# INLINE interpretLogStderrWith #-}
+{-# inline interpretLogStderrWith #-}
 
+-- |Like 'interpretLogStderrWith', but setting a log level.
+-- 'Nothing' causes no messages to be logged.
+interpretLogStderrLevelWith ::
+  Members [Embed IO, GhcTime] r =>
+  (LogEntry LogMessage -> Text) ->
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStderrLevelWith fmt level =
+  interpretDataLogStderrWith fmt .
+  setLogLevel level .
+  interpretTimeGhc .
+  interpretLogDataLog .
+  raiseUnder2
+{-# inline interpretLogStderrLevelWith #-}
+
 -- |Interpret 'Log' by printing to stderr, using the default formatter.
 --
 -- Since this adds a timestamp, it has a dependency on 'GhcTime'.
@@ -53,8 +70,18 @@
   InterpreterFor Log r
 interpretLogStderr =
   interpretLogStderrWith formatLogEntry
-{-# INLINE interpretLogStderr #-}
+{-# inline interpretLogStderr #-}
 
+-- |Like 'interpretLogStderr', but setting a log level.
+-- 'Nothing' causes no messages to be logged.
+interpretLogStderrLevel ::
+  Members [Embed IO, GhcTime] r =>
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStderrLevel =
+  interpretLogStderrLevelWith formatLogEntry
+{-# inline interpretLogStderrLevel #-}
+
 -- |Interpret 'Log' by printing to stderr, using the default formatter, then interpreting 'GhcTime'.
 interpretLogStderr' ::
   Member (Embed IO) r =>
@@ -63,7 +90,7 @@
   interpretTimeGhc .
   interpretLogStderr .
   raiseUnder
-{-# INLINE interpretLogStderr' #-}
+{-# inline interpretLogStderr' #-}
 
 -- |Like 'interpretLogStderr', but process messages concurrently.
 interpretLogStderrConc ::
@@ -74,4 +101,17 @@
   interpretDataLogStderrWith formatLogEntry .
   interpretLogDataLogConc 64 .
   raiseUnder2
-{-# INLINE interpretLogStderrConc #-}
+{-# inline interpretLogStderrConc #-}
+
+-- |Like 'interpretLogStderr', but process messages concurrently.
+interpretLogStderrLevelConc ::
+  Members [Resource, Async, Race, Embed IO] r =>
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStderrLevelConc level =
+  interpretTimeGhc .
+  interpretDataLogStderrWith formatLogEntry .
+  setLogLevel level .
+  interpretLogDataLogConc 64 .
+  raiseUnder2
+{-# inline interpretLogStderrLevelConc #-}
diff --git a/lib/Polysemy/Log/Stdout.hs b/lib/Polysemy/Log/Stdout.hs
--- a/lib/Polysemy/Log/Stdout.hs
+++ b/lib/Polysemy/Log/Stdout.hs
@@ -13,6 +13,8 @@
 import Polysemy.Log.Data.LogMessage (LogMessage)
 import Polysemy.Log.Format (formatLogEntry)
 import Polysemy.Log.Log (interpretDataLog, interpretLogDataLog, interpretLogDataLogConc)
+import Polysemy.Log.Data.Severity (Severity)
+import Polysemy.Log.Level (setLogLevel)
 
 -- |Interpret 'DataLog' by printing to stdout, converting messages to 'Text' with the supplied function.
 interpretDataLogStdoutWith ::
@@ -21,7 +23,7 @@
   InterpreterFor (DataLog a) r
 interpretDataLogStdoutWith fmt =
   interpretDataLog \ msg -> embed (Text.hPutStrLn stdout (fmt msg))
-{-# INLINE interpretDataLogStdoutWith #-}
+{-# inline interpretDataLogStdoutWith #-}
 
 -- |Interpret 'DataLog' by printing to stdout, converting messages to 'Text' by using 'Show'.
 interpretDataLogStdout ::
@@ -30,7 +32,7 @@
   InterpreterFor (DataLog a) r
 interpretDataLogStdout =
   interpretDataLogStdoutWith show
-{-# INLINE interpretDataLogStdout #-}
+{-# inline interpretDataLogStdout #-}
 
 -- |Interpret 'Log' by printing to stdout, converting messages to 'Text' with the supplied function.
 interpretLogStdoutWith ::
@@ -42,8 +44,23 @@
   interpretTimeGhc .
   interpretLogDataLog .
   raiseUnder2
-{-# INLINE interpretLogStdoutWith #-}
+{-# inline interpretLogStdoutWith #-}
 
+-- |Like 'interpretLogStdoutWith', but setting a log level.
+-- 'Nothing' causes no messages to be logged.
+interpretLogStdoutLevelWith ::
+  Members [Embed IO, GhcTime] r =>
+  (LogEntry LogMessage -> Text) ->
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStdoutLevelWith fmt level =
+  interpretDataLogStdoutWith fmt .
+  setLogLevel level .
+  interpretTimeGhc .
+  interpretLogDataLog .
+  raiseUnder2
+{-# inline interpretLogStdoutLevelWith #-}
+
 -- |Interpret 'Log' by printing to stdout, using the default formatter.
 --
 -- Since this adds a timestamp, it has a dependency on 'GhcTime'.
@@ -53,8 +70,18 @@
   InterpreterFor Log r
 interpretLogStdout =
   interpretLogStdoutWith formatLogEntry
-{-# INLINE interpretLogStdout #-}
+{-# inline interpretLogStdout #-}
 
+-- |Like 'interpretLogStdout', but setting a log level.
+-- 'Nothing' causes no messages to be logged.
+interpretLogStdoutLevel ::
+  Members [Embed IO, GhcTime] r =>
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStdoutLevel =
+  interpretLogStdoutLevelWith formatLogEntry
+{-# inline interpretLogStdoutLevel #-}
+
 -- |Interpret 'Log' by printing to stdout, using the default formatter, then interpreting 'GhcTime'.
 interpretLogStdout' ::
   Member (Embed IO) r =>
@@ -63,7 +90,7 @@
   interpretTimeGhc .
   interpretLogStdout .
   raiseUnder
-{-# INLINE interpretLogStdout' #-}
+{-# inline interpretLogStdout' #-}
 
 -- |Like 'interpretLogStdout', but process messages concurrently.
 interpretLogStdoutConc ::
@@ -74,4 +101,17 @@
   interpretDataLogStdoutWith formatLogEntry .
   interpretLogDataLogConc 64 .
   raiseUnder2
-{-# INLINE interpretLogStdoutConc #-}
+{-# inline interpretLogStdoutConc #-}
+
+-- |Like 'interpretLogStdout', but process messages concurrently.
+interpretLogStdoutLevelConc ::
+  Members [Resource, Async, Race, Embed IO] r =>
+  Maybe Severity ->
+  InterpreterFor Log r
+interpretLogStdoutLevelConc level =
+  interpretTimeGhc .
+  interpretDataLogStdoutWith formatLogEntry .
+  setLogLevel level .
+  interpretLogDataLogConc 64 .
+  raiseUnder2
+{-# inline interpretLogStdoutLevelConc #-}
diff --git a/polysemy-log.cabal b/polysemy-log.cabal
--- a/polysemy-log.cabal
+++ b/polysemy-log.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           polysemy-log
-version:        0.3.0.2
+version:        0.4.0.0
 synopsis:       Polysemy Effects for Logging
 description:    See <https://hackage.haskell.org/package/polysemy-log/docs/Polysemy-Log.html>
 category:       Logging
@@ -37,6 +37,7 @@
       Polysemy.Log.Data.LogMetadata
       Polysemy.Log.Data.Severity
       Polysemy.Log.Format
+      Polysemy.Log.Level
       Polysemy.Log.Log
       Polysemy.Log.Prelude
       Polysemy.Log.Pure
@@ -107,7 +108,7 @@
       UndecidableInstances
       UnicodeSyntax
       ViewPatterns
-  ghc-options: -flate-specialise -fspecialise-aggressively -Wall -Wredundant-constraints -Wunused-packages
+  ghc-options: -Wall -Wredundant-constraints -Wunused-packages -Widentities
   build-depends:
       ansi-terminal >=0.10.3
     , base ==4.*
@@ -115,7 +116,6 @@
     , polysemy-conc >=0.3
     , polysemy-time >=0.1.4
     , relude >=0.7
-    , string-interpolate >=0.2.1
     , template-haskell
     , text
     , time
@@ -193,7 +193,7 @@
       UndecidableInstances
       UnicodeSyntax
       ViewPatterns
-  ghc-options: -flate-specialise -fspecialise-aggressively -Wall -Wredundant-constraints -Wunused-packages -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -Wredundant-constraints -Wunused-packages -Widentities -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base ==4.*
     , polysemy >=1.5
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -6,7 +6,7 @@
 
 A common interface for the polysemy logging backend adapters.
 
-An example program using [co-log], for the simple logger with predefined formatting and a custom data type:
+An example program using a simple logger with predefined formatting and a custom data type:
 
 ```haskell
 import Colog (logTextStdout)