diff --git a/devforms.cabal b/devforms.cabal
--- a/devforms.cabal
+++ b/devforms.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               devforms
-version:            0.2.0.2
+version:            0.2.1.0
 synopsis:           A builder DSL for HTML survey forms with built-in server and storage
 description:
     devforms is a Haskell library for building HTML survey forms using a
@@ -18,6 +18,7 @@
 extra-source-files: static/_hyperscript.min.js
     , static/htmx.min.js
     , static/pico.classless.green.min.css
+    , static/validation-enhancer.min.js
 
 source-repository head
     type:     git
diff --git a/examples/Example.hs b/examples/Example.hs
--- a/examples/Example.hs
+++ b/examples/Example.hs
@@ -13,6 +13,16 @@
             , "Camel"
             , "Duck"
             ]
+        questionMultiChoiceWith
+            "Which animals have you seen?"
+            [ "Alpaca"
+            , "Bumblebee"
+            , "Camel"
+            , "Duck"
+            ]
+            $ do
+                setMinSelections 1 :: MultiChoiceQuestionBuilder ()
+                setMaxSelections 3
         questionDateWith "On which day would you like to meet your favourite animal?" $ setOptional
         questionTime "On which time would you like to have the meeting?"
         questionIntegerWith "How many siblings do you have?" $ do
@@ -21,6 +31,7 @@
     form "Another simple form" "otherform" $ do
         questionCheckbox "Do you want to check this box?"
         questionChoice "Select one of the following:" ["A", "B", "C"]
+        questionMultiChoice "Select all that apply:" ["X", "Y", "Z"]
         questionDate "Select a date"
         questionIntegerWith "Enter a natural number" $ do
             setUpperBoundInclusive 15
diff --git a/src/DevForms.hs b/src/DevForms.hs
--- a/src/DevForms.hs
+++ b/src/DevForms.hs
@@ -24,6 +24,9 @@
         questionLikert "I enjoy seeing animals"
         questionChoice "Favourite animal"
             ["Alpaca", "Bumblebee", "Camel", "Duck"]
+        questionMultiChoiceWith "Which animals have you seen?" ["Alpaca", "Bumblebee", "Camel", "Duck"] $ do
+            setMinSelections 1
+            setMaxSelections 3
         questionDateWith "When would you like to visit the zoo?" $ setOptional
         questionIntegerWith "How many tickets?" $ do
             setLowerBoundInclusive 1
@@ -35,8 +38,10 @@
     FormBuilder,
     QuestionBuilder,
     IntegerQuestionBuilder,
+    MultiChoiceQuestionBuilder,
     HasOptional (..),
     HasBounds (..),
+    HasSelectionBounds (..),
     devFormServer,
     form,
     questionCheckbox,
@@ -45,6 +50,8 @@
     questionLikertWith,
     questionChoice,
     questionChoiceWith,
+    questionMultiChoice,
+    questionMultiChoiceWith,
     questionDate,
     questionDateWith,
     questionTime,
@@ -62,11 +69,14 @@
 import Question (
     HasBounds (..),
     HasOptional (..),
+    HasSelectionBounds (..),
     IntegerQuestionBuilder,
+    MultiChoiceQuestionBuilder,
     Question (..),
     QuestionBuilder,
     QuestionType (..),
     runIntegerQuestionBuilder,
+    runMultiChoiceQuestionBuilder,
     runQuestionBuilder,
  )
 import Server (Server (..), ServerBuilder, runServer)
@@ -157,6 +167,41 @@
 questionChoiceWith :: Text -> [Text] -> QuestionBuilder () -> FormBuilder ()
 questionChoiceWith title qOptions builder =
     addQuestion $ Question title (QuestionChoice qOptions) (runQuestionBuilder builder)
+
+{- | Add a multiple-choice question with default options. Renders as a group of
+checkboxes — the respondent can select one or more of the provided options.
+
+The first argument is the question label; the second is the list of choices.
+By default, at least one selection is required. Use 'questionMultiChoiceWith'
+to configure selection bounds or mark as optional.
+-}
+questionMultiChoice :: Text -> [Text] -> FormBuilder ()
+questionMultiChoice label options = questionMultiChoiceWith label options (pure ())
+
+{- | Add a multiple-choice question with custom options. Renders as a group of
+checkboxes — the respondent can select one or more of the provided options.
+
+The first argument is the question label; the second is the list of choices.
+The third argument is a 'MultiChoiceQuestionBuilder' block where you can
+configure selection bounds using 'setMinSelections' and 'setMaxSelections',
+as well as shared options like 'setOptional'.
+
+Selection bounds are enforced both client-side (via _hyperscript) and
+server-side on submission. If the question is optional, the respondent may
+skip it entirely (zero selections), but if they select any options, the
+min\/max constraints must be satisfied.
+
+=== Example
+
+@
+questionMultiChoiceWith "Pick your toppings" ["Cheese", "Mushrooms", "Peppers", "Olives"] $ do
+    setMinSelections 1
+    setMaxSelections 3
+@
+-}
+questionMultiChoiceWith :: Text -> [Text] -> MultiChoiceQuestionBuilder () -> FormBuilder ()
+questionMultiChoiceWith title qOptions builder =
+    addQuestion $ Question title (QuestionMultiChoice qOptions) (runMultiChoiceQuestionBuilder builder)
 
 {- | Add a date-picker question with default options. Renders as an HTML date
 input and stores the answer in @YYYY-MM-DD@ format.
diff --git a/src/Question.hs b/src/Question.hs
--- a/src/Question.hs
+++ b/src/Question.hs
@@ -7,10 +7,13 @@
     QuestionOptions (..),
     QuestionBuilder,
     IntegerQuestionBuilder,
+    MultiChoiceQuestionBuilder,
     HasOptional (..),
     HasBounds (..),
+    HasSelectionBounds (..),
     runQuestionBuilder,
     runIntegerQuestionBuilder,
+    runMultiChoiceQuestionBuilder,
     defaultOptions,
     renderQuestion,
     parseAnswers,
@@ -33,17 +36,19 @@
     }
     deriving (Show)
 
-data QuestionType = QuestionCheckbox | QuestionLikert | QuestionChoice [Text] | QuestionDate | QuestionInteger | QuestionTime | QuestionFreeText | QuestionRegexText Text deriving (Show)
+data QuestionType = QuestionCheckbox | QuestionLikert | QuestionChoice [Text] | QuestionMultiChoice [Text] | QuestionDate | QuestionInteger | QuestionTime | QuestionFreeText | QuestionRegexText Text deriving (Show)
 
 data QuestionOptions = QuestionOptions
     { isOptional :: Bool
     , lowerBoundInclusive :: Maybe Integer
     , upperBoundInclusive :: Maybe Integer
+    , minSelections :: Maybe Int
+    , maxSelections :: Maybe Int
     }
     deriving (Show)
 
 defaultOptions :: QuestionOptions
-defaultOptions = QuestionOptions{isOptional = False, lowerBoundInclusive = Nothing, upperBoundInclusive = Nothing}
+defaultOptions = QuestionOptions{isOptional = False, lowerBoundInclusive = Nothing, upperBoundInclusive = Nothing, minSelections = Nothing, maxSelections = Nothing}
 
 -- | A builder monad for configuring shared question options (e.g. optionality).
 newtype QuestionBuilder a = QuestionBuilder (Writer (Endo QuestionOptions) a)
@@ -53,6 +58,10 @@
 newtype IntegerQuestionBuilder a = IntegerQuestionBuilder (Writer (Endo QuestionOptions) a)
     deriving newtype (Functor, Applicative, Monad)
 
+-- | A builder monad for configuring multi-choice question options (selection bounds and optionality).
+newtype MultiChoiceQuestionBuilder a = MultiChoiceQuestionBuilder (Writer (Endo QuestionOptions) a)
+    deriving newtype (Functor, Applicative, Monad)
+
 -- | Typeclass for builders that support marking a question as optional.
 class HasOptional m where
     setOptional :: m
@@ -62,6 +71,11 @@
     setLowerBoundInclusive :: Integer -> m
     setUpperBoundInclusive :: Integer -> m
 
+-- | Typeclass for builders that support setting selection count bounds.
+class HasSelectionBounds m where
+    setMinSelections :: Int -> m
+    setMaxSelections :: Int -> m
+
 instance HasOptional (QuestionBuilder ()) where
     setOptional = QuestionBuilder $ tell $ Endo $ \o -> o{isOptional = True}
 
@@ -72,8 +86,15 @@
     setLowerBoundInclusive bound = IntegerQuestionBuilder $ tell $ Endo $ \o -> o{lowerBoundInclusive = Just bound}
     setUpperBoundInclusive bound = IntegerQuestionBuilder $ tell $ Endo $ \o -> o{upperBoundInclusive = Just bound}
 
-data AnswerError = NoRegexMatch Text | MissingRequiredField Text | InvalidTimeFormatFor Text | InvalidDateFormatFor Text | InvalidLikertOptionFor Text | InvalidChoiceFor Text | InvalidIntegerFor Text IntegerBoundError | IntegerParseErrorFor Text deriving (Show)
+instance HasOptional (MultiChoiceQuestionBuilder ()) where
+    setOptional = MultiChoiceQuestionBuilder $ tell $ Endo $ \o -> o{isOptional = True}
 
+instance HasSelectionBounds (MultiChoiceQuestionBuilder ()) where
+    setMinSelections n = MultiChoiceQuestionBuilder $ tell $ Endo $ \o -> o{minSelections = Just n}
+    setMaxSelections n = MultiChoiceQuestionBuilder $ tell $ Endo $ \o -> o{maxSelections = Just n}
+
+data AnswerError = NoRegexMatch Text | MissingRequiredField Text | InvalidTimeFormatFor Text | InvalidDateFormatFor Text | InvalidLikertOptionFor Text | InvalidChoiceFor Text | InvalidIntegerFor Text IntegerBoundError | IntegerParseErrorFor Text | InvalidSelectionCountFor Text deriving (Show)
+
 -- | Run a 'QuestionBuilder' to extract the configured 'QuestionOptions'.
 runQuestionBuilder :: QuestionBuilder () -> QuestionOptions
 runQuestionBuilder (QuestionBuilder w) = appEndo (execWriter w) defaultOptions
@@ -82,6 +103,10 @@
 runIntegerQuestionBuilder :: IntegerQuestionBuilder () -> QuestionOptions
 runIntegerQuestionBuilder (IntegerQuestionBuilder w) = appEndo (execWriter w) defaultOptions
 
+-- | Run a 'MultiChoiceQuestionBuilder' to extract the configured 'QuestionOptions'.
+runMultiChoiceQuestionBuilder :: MultiChoiceQuestionBuilder () -> QuestionOptions
+runMultiChoiceQuestionBuilder (MultiChoiceQuestionBuilder w) = appEndo (execWriter w) defaultOptions
+
 runJust :: a -> Maybe b -> (b -> a) -> a
 runJust _ (Just x) f = f x
 runJust defaultValue Nothing _ = defaultValue
@@ -101,6 +126,7 @@
         let requiredAttrs = if isRequired then [required_ ""] else []
         case questionType of
             QuestionChoice _ -> mempty
+            QuestionMultiChoice _ -> mempty
             QuestionLikert -> mempty
             _ -> label_ [Lucid.for_ qId] $ toHtml questionText
         case questionType of
@@ -124,6 +150,83 @@
                         div_ $ do
                             input_ $ [id_ (qId <> c), type_ "radio", name_ qId, value_ c, ariaErrormessage_ errId, script_ radioScript] <> requiredAttrs
                             label_ [Lucid.for_ (qId <> c)] $ toHtml c
+            QuestionMultiChoice choices -> do
+                let QuestionOptions{minSelections = minSel, maxSelections = maxSel} = questionOptions
+                let effectiveMin = fromMaybe (if isRequired then 1 else 0) minSel :: Int
+                let effectiveMax = fromMaybe (length choices) maxSel :: Int
+                let isOpt = isOptional questionOptions
+                let optionalCheck = if isOpt then ("true" :: Text) else "false"
+                let minText = show effectiveMin :: Text
+                let maxText = show effectiveMax :: Text
+                let proxyId = qId <> "-proxy"
+                let validationMsg = "Please select between " <> minText <> " and " <> maxText <> " options"
+                let checkboxScript =
+                        [__i|
+                      on change
+                        set boxes to <input[type='checkbox']/> in closest <fieldset/>
+                        set count to 0
+                        for box in boxes
+                          if box.checked increment count
+                        end
+                        set isValid to false
+                        if #{optionalCheck} and count === 0
+                          set isValid to true
+                        else if count >= #{minText} and count <= #{maxText}
+                          set isValid to true
+                        end
+                        if count > #{maxText}
+                          set my.checked to false
+                          halt
+                        end
+                        set proxy to document.getElementById('#{proxyId}')
+                        if isValid
+                          set proxy.value to 'valid'
+                          js(proxy) proxy.setCustomValidity('') end
+                          for box in boxes
+                            js(box) box.setCustomValidity('') end
+                            remove .invalid from box
+                            add .valid to box
+                          end
+                        else
+                          set proxy.value to ''
+                          js(proxy) proxy.setCustomValidity('#{validationMsg}') end
+                          for box in boxes
+                            js(box) box.setCustomValidity('#{validationMsg}') end
+                            remove .valid from box
+                            add .invalid to box
+                          end
+                        end
+                      end
+                    |] ::
+                            Text
+                let proxyScript =
+                        [__i|
+                      on load
+                        set boxes to <input[type='checkbox']/> in closest <fieldset/>
+                        set msg to '#{validationMsg}'
+                        if not #{optionalCheck}
+                          for box in boxes
+                            js(box, msg) box.setCustomValidity(msg) end
+                          end
+                        end
+                      end
+                    |] ::
+                            Text
+                fieldset_ $ do
+                    legend_ $ toHtml questionText
+                    input_ $
+                        [ id_ proxyId
+                        , type_ "text"
+                        , style_ "display:none"
+                        , tabindex_ "-1"
+                        , ariaErrormessage_ errId
+                        , script_ proxyScript
+                        ]
+                            <> requiredAttrs
+                    forM_ choices $ \c -> do
+                        div_ $ do
+                            input_ [id_ (qId <> "-" <> c), type_ "checkbox", name_ (qId <> "-" <> c), ariaErrormessage_ errId, script_ checkboxScript]
+                            label_ [Lucid.for_ (qId <> "-" <> c)] $ toHtml c
             QuestionDate -> do
                 input_ $ [type_ "date", name_ questionText, ariaErrormessage_ errId] <> requiredAttrs
             QuestionInteger -> do
@@ -262,6 +365,21 @@
                     Just raw
                         | raw `elem` choices -> Right (Key.fromText questionText, JSON.toJSON raw)
                         | otherwise -> Left $ InvalidChoiceFor questionText
+            QuestionMultiChoice choices ->
+                let selected = filter (\c -> isJust $ Map.lookup (questionText <> "-" <> c) params') choices
+                    count = length selected
+                    QuestionOptions{minSelections = minSel, maxSelections = maxSel} = questionOptions
+                    effectiveMin = fromMaybe (if isOptional questionOptions then 0 else 1) minSel
+                    effectiveMax = fromMaybe (length choices) maxSel
+                 in if count == 0 && isOptional questionOptions
+                        then Right (Key.fromText questionText, JSON.Null)
+                        else
+                            if count == 0 && not (isOptional questionOptions)
+                                then Left $ MissingRequiredField questionText
+                                else
+                                    if count < effectiveMin || count > effectiveMax
+                                        then Left $ InvalidSelectionCountFor questionText
+                                        else Right (Key.fromText questionText, JSON.toJSON selected)
             QuestionLikert ->
                 let likertOptions =
                         [ "Strongly disagree"
diff --git a/static/validation-enhancer.min.js b/static/validation-enhancer.min.js
new file mode 100644
--- /dev/null
+++ b/static/validation-enhancer.min.js
@@ -0,0 +1,1 @@
+class t extends HTMLElement{get validClass(){return this.getAttribute("valid-class")||"valid"}get invalidClass(){return this.getAttribute("invalid-class")||"invalid"}get messageTargetAttr(){return this.getAttribute("message-target-attr")||"aria-errormessage"}get messagePrefix(){return this.getAttribute("message-prefix")||"validation"}get messageAriaLive(){return this.getAttribute("message-aria-live")||"polite"}get scrollIntoViewOptions(){const t=this.getAttribute("scroll-align-to-top");if(null!==t)return"false"!==t;const e={behavior:this.getAttribute("scroll-behavior")||"smooth"},i=this.getAttribute("scroll-block");i&&(e.block=i);const s=this.getAttribute("scroll-inline");return s&&(e.inline=s),e}mutationObserver=null;constructor(){super(),this.handleChangeAndFocusOut=this.handleChangeAndFocusOut.bind(this),this.handleKeyUp=this.handleKeyUp.bind(this),this.handleSubmit=this.handleSubmit.bind(this),this.handleMutation=this.handleMutation.bind(this)}connectedCallback(){this.addEventListener("keyup",this.handleKeyUp),this.addEventListener("change",this.handleChangeAndFocusOut),this.addEventListener("focusout",this.handleChangeAndFocusOut),this.addEventListener("submit",this.handleSubmit);const t=this.querySelectorAll(`[${this.messageTargetAttr}]`);this.setupValidationTargetElements(Array.from(t));const e=this.querySelectorAll("form");this.setupForms(Array.from(e)),this.mutationObserver=new MutationObserver(this.handleMutation),this.mutationObserver.observe(this,{childList:!0,subtree:!0})}disconnectedCallback(){this.removeEventListener("keyup",this.handleKeyUp),this.removeEventListener("focusout",this.handleChangeAndFocusOut),this.removeEventListener("change",this.handleChangeAndFocusOut),this.removeEventListener("submit",this.handleSubmit),this.mutationObserver?.disconnect(),this.mutationObserver=null}handleMutation(t){t.forEach(t=>{const e=Array.from(t.addedNodes).filter(t=>t instanceof Element);this.setupValidationTargetElements(e);const i=e.filter(t=>t instanceof HTMLFormElement);this.setupForms(i)})}setupForms(t){t.forEach(t=>t.noValidate=!0)}ensureAriaLive(t){t.id&&this.querySelector(`[${this.messageTargetAttr}="${CSS.escape(t.id)}"]`)&&(t.hasAttribute("aria-live")||t.setAttribute("aria-live",this.messageAriaLive))}setupValidationTargetElements(t){t.forEach(t=>{const e=this.getValidationMessageTargetElement(t);e&&(e.hasAttribute("aria-live")||e.setAttribute("aria-live",this.messageAriaLive))})}handleKeyUp(t){const e=t.target;e&&this.validateInputPolitely(e)}handleChangeAndFocusOut(t){const e=t.target;this.isValidatableInput(e)&&this.validateInput(e)}handleSubmit(t){const e=t.target;if(!e)return;this.validateAllInputs(e)||(t.preventDefault(),t.stopPropagation())}validateInput(t){return!this.isValidatableInput(t)||(t.checkValidity()?(this.makeInputValid(t),!0):(this.makeInputInvalid(t),!1))}validateInputPolitely(t){return!this.isValidatableInput(t)||(t.checkValidity()?(this.makeInputValid(t),!0):(this.removeInputValidity(t),!1))}validateAllInputs(t){let e=!1;const i=this.getValidatableInputs(t);let s=!0;for(const t of i){if(!this.validateInput(t)&&(s=!1,!e)){e=!0;const i=this.getLabel(t)||t;this.scrollToElement(i),t.focus()}}return s}isValidatableInput(t){return!!t&&!(t instanceof HTMLButtonElement)&&"checkValidity"in t}makeInputValid(t){t.classList.add(this.validClass),t.classList.remove(this.invalidClass),t.removeAttribute("aria-invalid"),this.clearMessage(t)}makeInputInvalid(t){t.classList.add(this.invalidClass),t.classList.remove(this.validClass),t.setAttribute("aria-invalid","true"),this.showMessage(t)}removeInputValidity(t){t.classList.remove(this.validClass)}showMessage(t){const e=this.getCustomMessage(t)||t.validationMessage,i=this.getValidationMessageTargetElement(t);i&&(i.textContent=e)}clearMessage(t){const e=this.getValidationMessageTargetElement(t);e&&(e.textContent="")}getValidationMessageTargetElement(t){const e=t.getAttribute(this.messageTargetAttr);return e&&this.querySelector(`#${CSS.escape(e)}`)||null}validityKeys=["valueMissing","typeMismatch","patternMismatch","tooLong","tooShort","rangeUnderflow","rangeOverflow","stepMismatch","badInput"];getCustomMessage(t){if(!t.validity)return null;const e=this.messagePrefix;for(const i of this.validityKeys)if(i in t.validity&&t.validity[i])return t.getAttribute(`${e}-${i}`)??t.getAttribute(`data-${e}-${i}`);return null}getValidatableInputs(t){return Array.from(t.elements??[]).filter(this.isValidatableInput)}scrollToElement(t){const e=this.getAttribute("scroll-container");if(e){const i=document.querySelector(e);if(i){const e=i.getBoundingClientRect(),s=t.getBoundingClientRect(),a=this.scrollIntoViewOptions,n="boolean"==typeof a?"auto":a.behavior||"auto";return void i.scrollTo({top:i.scrollTop+(s.top-e.top),left:i.scrollLeft+(s.left-e.left),behavior:n})}}t.scrollIntoView(this.scrollIntoViewOptions)}getLabel(t){return t.id?document.querySelector(`label[for=${CSS.escape(t.id)}]`):null}}customElements.define("validation-enhancer",t);export{t as ValidationEnhancer};