diff --git a/Userland/Libraries/LibWeb/HTML/AttributeNames.h b/Userland/Libraries/LibWeb/HTML/AttributeNames.h
index a8ec466eda..fdb9f0eb37 100644
--- a/Userland/Libraries/LibWeb/HTML/AttributeNames.h
+++ b/Userland/Libraries/LibWeb/HTML/AttributeNames.h
@@ -24,6 +24,7 @@ namespace AttributeNames {
     __ENUMERATE_HTML_ATTRIBUTE(alt)                        \
     __ENUMERATE_HTML_ATTRIBUTE(archive)                    \
     __ENUMERATE_HTML_ATTRIBUTE(async)                      \
+    __ENUMERATE_HTML_ATTRIBUTE(autocomplete)               \
     __ENUMERATE_HTML_ATTRIBUTE(autofocus)                  \
     __ENUMERATE_HTML_ATTRIBUTE(autoplay)                   \
     __ENUMERATE_HTML_ATTRIBUTE(axis)                       \
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLButtonElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLButtonElement.idl
index 6e58725ed6..3df1dc57cd 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLButtonElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLButtonElement.idl
@@ -1,16 +1,29 @@
 #import <HTML/HTMLElement.idl>
+#import <HTML/HTMLFormElement.idl>
 
 // https://html.spec.whatwg.org/multipage/semantics.html#htmlbuttonelement
 [Exposed=Window]
 interface HTMLButtonElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
     [CEReactions, Reflect] attribute boolean disabled;
+    readonly attribute HTMLFormElement? form;
+    [CEReactions, Reflect=formaction] attribute USVString formAction;
+    [CEReactions, Reflect=formenctype] attribute DOMString formEnctype;
+    [CEReactions, Reflect=formmethod] attribute DOMString formMethod;
     [CEReactions, Reflect=formnovalidate] attribute boolean formNoValidate;
     [CEReactions, Reflect=formtarget] attribute DOMString formTarget;
     [CEReactions, Reflect] attribute DOMString name;
+    [CEReactions, Reflect] attribute DOMString type;
     [CEReactions, Reflect] attribute DOMString value;
-    [CEReactions] attribute DOMString type;
 
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
+    // FIXME: boolean checkValidity();
+    // FIXME: boolean reportValidity();
+    // FIXME: undefined setCustomValidity(DOMString error);
+
+    // FIXME: readonly attribute NodeList labels;
 };
+// FIXME: HTMLButtonElement includes PopoverInvokerElement;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLDataListElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLDataListElement.idl
index 7044b6395c..f9b29425f7 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLDataListElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLDataListElement.idl
@@ -3,7 +3,7 @@
 // https://html.spec.whatwg.org/multipage/semantics.html#htmldatalistelement
 [Exposed=Window]
 interface HTMLDataListElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
+    // FIXME: [SameObject] readonly attribute HTMLCollection options;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFieldSetElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLFieldSetElement.idl
index 4b75e09bc7..cf35c6d1f2 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFieldSetElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFieldSetElement.idl
@@ -1,11 +1,23 @@
 #import <HTML/HTMLElement.idl>
+#import <HTML/HTMLFormElement.idl>
 
 // https://html.spec.whatwg.org/multipage/semantics.html#htmlfieldsetelement
 [Exposed=Window]
 interface HTMLFieldSetElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
+    [CEReactions, Reflect] attribute boolean disabled;
+    readonly attribute HTMLFormElement? form;
+    [CEReactions, Reflect] attribute DOMString name;
+
     readonly attribute DOMString type;
 
+    // FIXME: [SameObject] readonly attribute HTMLCollection elements;
+
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: [SameObject] readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
+    // FIXME: boolean checkValidity();
+    // FIXME: boolean reportValidity();
+    // FIXME: undefined setCustomValidity(DOMString error);
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
index 767ba66aa4..99c43e9609 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.idl
@@ -5,49 +5,69 @@
 // https://html.spec.whatwg.org/multipage/input.html#htmlinputelement
 [Exposed=Window]
 interface HTMLInputElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
-    readonly attribute HTMLFormElement? form;
-    attribute FileList? files;
-
     [CEReactions, Reflect] attribute DOMString accept;
     [CEReactions, Reflect] attribute DOMString alt;
-    [CEReactions, Reflect] attribute DOMString max;
-    [CEReactions, Reflect] attribute DOMString min;
-    [CEReactions, Reflect] attribute DOMString pattern;
-    [CEReactions, Reflect] attribute DOMString placeholder;
-    [CEReactions, Reflect] attribute DOMString src;
-    [CEReactions, Reflect] attribute DOMString step;
-    [CEReactions, Reflect] attribute DOMString name;
-    [CEReactions, Reflect=dirname] attribute DOMString dirName;
-    [CEReactions, Reflect=value] attribute DOMString defaultValue;
-
-    [CEReactions] attribute DOMString type;
-    attribute boolean indeterminate;
-
-    [CEReactions, LegacyNullToEmptyString] attribute DOMString value;
-
-    [ImplementedAs=checked_binding] attribute boolean checked;
-
-    [CEReactions, Reflect] attribute boolean disabled;
+    // FIXME: [CEReactions] attribute DOMString autocomplete;
     [CEReactions, Reflect=checked] attribute boolean defaultChecked;
-    [CEReactions, Reflect=formnovalidate] attribute boolean formNoValidate;
+    [ImplementedAs=checked_binding] attribute boolean checked;
+    [CEReactions, Reflect=dirname] attribute DOMString dirName;
+    [CEReactions, Reflect] attribute boolean disabled;
+    readonly attribute HTMLFormElement? form;
+    attribute FileList? files;
+    // FIXME: [CEReactions] attribute USVString formAction;
+    // FIXME: [CEReactions] attribute DOMString formEnctype;
+    // FIXME: [CEReactions] attribute DOMString formMethod;
+   [CEReactions, Reflect=formnovalidate] attribute boolean formNoValidate;
     [CEReactions, Reflect=formtarget] attribute DOMString formTarget;
+    // FIXME: [CEReactions] attribute unsigned long height;
+    attribute boolean indeterminate;
+    // FIXME: readonly attribute HTMLDataListElement? list;
+    [CEReactions, Reflect] attribute DOMString max;
+    // FIXME: [CEReactions] attribute long maxLength;
+    [CEReactions, Reflect] attribute DOMString min;
+    // FIXME: [CEReactions] attribute long minLength;
     [CEReactions, Reflect] attribute boolean multiple;
+    [CEReactions, Reflect] attribute DOMString name;
+    // FIXME: [CEReactions] attribute DOMString pattern;
+    [CEReactions, Reflect] attribute DOMString placeholder;
     [CEReactions, Reflect=readonly] attribute boolean readOnly;
     [CEReactions, Reflect] attribute boolean required;
+    // FIXME: [CEReactions] attribute unsigned long size;
+    [CEReactions, Reflect] attribute DOMString src;
+    [CEReactions, Reflect] attribute DOMString step;
+    [CEReactions] attribute DOMString type;
+    [CEReactions, Reflect=value] attribute DOMString defaultValue;
+    [CEReactions, LegacyNullToEmptyString] attribute DOMString value;
+    // FIXME: attribute object? valueAsDate;
+    // FIXME: attribute unrestricted double valueAsNumber;
+    // FIXME: [CEReactions] attribute unsigned long width;
 
-    [CEReactions, Reflect] attribute DOMString align;
-    [CEReactions, Reflect=usemap] attribute DOMString useMap;
+    // FIXME: undefined stepUp(optional long n = 1);
+    // FIXME: undefined stepDown(optional long n = 1);
 
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
     boolean checkValidity();
     boolean reportValidity();
     undefined setCustomValidity(DOMString error);
 
+    // FIXME: readonly attribute NodeList? labels;
+
     undefined select();
+    // FIXME: attribute unsigned long? selectionStart;
+    // FIXME: attribute unsigned long? selectionEnd;
+    // FIXME: attribute DOMString? selectionDirection;
+    // FIXME: undefined setRangeText(DOMString replacement);
+    // FIXME: undefined setRangeText(DOMString replacement, unsigned long start, unsigned long end, optional SelectionMode selectionMode = "preserve");
     undefined setSelectionRange(unsigned long start, unsigned long end, optional DOMString direction);
 
     undefined showPicker();
 
+    // Obsolete
+    [CEReactions, Reflect] attribute DOMString align;
+    [CEReactions, Reflect=usemap] attribute DOMString useMap;
 };
+// FIXME: HTMLInputElement includes PopoverInvokerElement;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLLegendElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLLegendElement.idl
index 506853c9d9..392420876a 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLLegendElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLLegendElement.idl
@@ -3,9 +3,10 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmllegendelement
 [Exposed=Window]
 interface HTMLLegendElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
-    [CEReactions, Reflect] attribute DOMString align;
+    // FIXME: readonly attribute HTMLFormElement? form;
 
+    // Obsolete
+    [CEReactions, Reflect] attribute DOMString align;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMeterElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLMeterElement.idl
index a491868f87..0b63c71d99 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMeterElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMeterElement.idl
@@ -3,7 +3,13 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmlmeterelement
 [Exposed=Window]
 interface HTMLMeterElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
+    // FIXME: [CEReactions] attribute double value;
+    // FIXME: [CEReactions] attribute double min;
+    // FIXME: [CEReactions] attribute double max;
+    // FIXME: [CEReactions] attribute double low;
+    // FIXME: [CEReactions] attribute double high;
+    // FIXME: [CEReactions] attribute double optimum;
+    // FIXME: readonly attribute NodeList labels;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLOptGroupElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLOptGroupElement.idl
index 04b5872904..29668618a2 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLOptGroupElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLOptGroupElement.idl
@@ -3,10 +3,8 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmloptgroupelement
 [Exposed=Window]
 interface HTMLOptGroupElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
     [CEReactions, Reflect] attribute boolean disabled;
     [CEReactions, Reflect] attribute DOMString label;
-
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLOptionElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLOptionElement.idl
index b1807007ac..c80229a2f5 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLOptionElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLOptionElement.idl
@@ -3,15 +3,15 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmloptionelement
 [Exposed=Window,  LegacyFactoryFunction=Option(optional DOMString text = "", optional DOMString value, optional boolean defaultSelected = false, optional boolean selected = false)]
 interface HTMLOptionElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
     [CEReactions, Reflect] attribute boolean disabled;
+    // FIXME: readonly attribute HTMLFormElement? form;
+    [CEReactions, Reflect] attribute DOMString label;
     [CEReactions, Reflect=selected] attribute boolean defaultSelected;
     attribute boolean selected;
     [CEReactions] attribute DOMString value;
 
     [CEReactions] attribute DOMString text;
     readonly attribute long index;
-
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLOutputElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLOutputElement.idl
index 7768b42484..35145e17c6 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLOutputElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLOutputElement.idl
@@ -1,11 +1,25 @@
 #import <HTML/HTMLElement.idl>
+#import <HTML/HTMLFormElement.idl>
 
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmloutputelement
 [Exposed=Window]
 interface HTMLOutputElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
-    readonly attribute DOMString type;
+    // FIXME: [SameObject, PutForwards=value] readonly attribute DOMTokenList htmlFor;
+    readonly attribute HTMLFormElement? form;
+    [CEReactions, Reflect] attribute DOMString name;
 
+    readonly attribute DOMString type;
+    // FIXME: [CEReactions] attribute DOMString defaultValue;
+    // FIXME: [CEReactions] attribute DOMString value;
+
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
+    // FIXME: boolean checkValidity();
+    // FIXME: boolean reportValidity();
+    // FIXME: undefined setCustomValidity(DOMString error);
+
+    // FIXME: readonly attribute NodeList labels;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.idl
index 59071ba621..a2d483f0c8 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.idl
@@ -3,11 +3,10 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmlprogresselement
 [Exposed=Window]
 interface HTMLProgressElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
     [CEReactions] attribute double value;
     [CEReactions] attribute double max;
     readonly attribute double position;
-
+    // FIXME: readonly attribute NodeList labels;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.idl
index d57ca829c1..93d9733256 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.idl
@@ -4,21 +4,40 @@
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmlselectelement
 [Exposed=Window]
 interface HTMLSelectElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
+    [CEReactions, Reflect] attribute DOMString autocomplete;
     [CEReactions, Reflect] attribute boolean disabled;
+    readonly attribute HTMLFormElement? form;
     [CEReactions, Reflect] attribute boolean multiple;
+    [CEReactions, Reflect] attribute DOMString name;
     [CEReactions, Reflect] attribute boolean required;
-    [SameObject] readonly attribute HTMLOptionsCollection options;
+    // FIXME: [CEReactions] attribute unsigned long size;
 
     readonly attribute DOMString type;
 
-    readonly attribute unsigned long length;
+    [SameObject] readonly attribute HTMLOptionsCollection options;
+    // FIXME: This isn't readonly
+    [CEReactions] readonly attribute unsigned long length;
+    // FIXME: Element is really HTMLOptionElement
     getter Element? item(unsigned long index);
-    getter Element? namedItem(DOMString name);
+    // FIXME: Element is really HTMLOptionElement
+    Element? namedItem(DOMString name);
     [CEReactions] undefined add((HTMLOptionElement or HTMLOptGroupElement) element, optional (HTMLElement or long)? before = null);
+    // FIXME: [CEReactions] undefined remove(); // ChildNode overload
+    // FIXME: [CEReactions] undefined remove(long index);
+    // FIXME: [CEReactions] setter undefined (unsigned long index, HTMLOptionElement? option);
 
+    // FIXME: [SameObject] readonly attribute HTMLCollection selectedOptions;
     attribute long selectedIndex;
+    // FIXME: attribute DOMString value;
 
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
+    // FIXME: boolean checkValidity();
+    // FIXME: boolean reportValidity();
+    // FIXME: undefined setCustomValidity(DOMString error);
+
+    // FIXME: readonly attribute NodeList labels;
 };
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
index 2ade76aaca..1ef0a88ee9 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.idl
@@ -1,18 +1,44 @@
 #import <HTML/HTMLElement.idl>
+#import <HTML/HTMLFormElement.idl>
 
 // https://html.spec.whatwg.org/multipage/form-elements.html#htmltextareaelement
 [Exposed=Window]
 interface HTMLTextAreaElement : HTMLElement {
-
     [HTMLConstructor] constructor();
 
-    [CEReactions, Reflect] attribute DOMString placeholder;
-    [CEReactions, Reflect] attribute DOMString name;
-    [CEReactions, Reflect] attribute DOMString wrap;
-    readonly attribute DOMString type;
-
+    [CEReactions, Reflect] attribute DOMString autocomplete;
+    // FIXME: [CEReactions] attribute unsigned long cols;
+    [CEReactions, Reflect=dirname] attribute DOMString dirName;
     [CEReactions, Reflect] attribute boolean disabled;
+    readonly attribute HTMLFormElement? form;
+    // FIXME: [CEReactions] attribute long maxLength;
+    // FIXME: [CEReactions] attribute long minLength;
+    [CEReactions, Reflect] attribute DOMString name;
+    [CEReactions, Reflect] attribute DOMString placeholder;
     [CEReactions, Reflect=readonly] attribute boolean readOnly;
     [CEReactions, Reflect] attribute boolean required;
+    // FIXME: [CEReactions] attribute unsigned long rows;
+    [CEReactions, Reflect] attribute DOMString wrap;
 
+    readonly attribute DOMString type;
+    // FIXME: [CEReactions] attribute DOMString defaultValue;
+    // FIXME: attribute [LegacyNullToEmptyString] DOMString value;
+    // FIXME: readonly attribute unsigned long textLength;
+
+    // FIXME: readonly attribute boolean willValidate;
+    // FIXME: readonly attribute ValidityState validity;
+    // FIXME: readonly attribute DOMString validationMessage;
+    // FIXME: boolean checkValidity();
+    // FIXME: boolean reportValidity();
+    // FIXME: undefined setCustomValidity(DOMString error);
+
+    // FIXME: readonly attribute NodeList labels;
+
+    // FIXME: undefined select();
+    // FIXME: attribute unsigned long selectionStart;
+    // FIXME: attribute unsigned long selectionEnd;
+    // FIXME: attribute DOMString selectionDirection;
+    // FIXME: undefined setRangeText(DOMString replacement);
+    // FIXME: undefined setRangeText(DOMString replacement, unsigned long start, unsigned long end, optional SelectionMode selectionMode = "preserve");
+    // FIXME: undefined setSelectionRange(unsigned long start, unsigned long end, optional DOMString direction);
 };