diff --git a/src/app/components/message/MsgTypeRenderers.tsx b/src/app/components/message/MsgTypeRenderers.tsx
index f86323e..5459c48 100644
--- a/src/app/components/message/MsgTypeRenderers.tsx
+++ b/src/app/components/message/MsgTypeRenderers.tsx
@@ -2,7 +2,7 @@ import React, { CSSProperties, ReactNode } from 'react';
 import { Box, Chip, Text, toRem } from 'folds';
 import { Icon, Icons } from '../icons';
 import { IContent } from 'matrix-js-sdk';
-import { JUMBO_EMOJI_REG, URL_REG } from '../../utils/regex';
+import { URL_REG, isJumboEmoji } from '../../utils/regex';
 import { trimReplyFromBody } from '../../utils/room';
 import { MessageTextBody } from './layout';
 import {
@@ -92,7 +92,7 @@ export function MText({ edited, content, renderBody, renderUrlsPreview, style }:
     <>
       <MessageTextBody
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={isJumboEmoji(trimmedBody, trimmedCustomBody)}
         style={style}
       >
         {renderBody({
@@ -135,7 +135,7 @@ export function MEmote({
       <MessageTextBody
         emote
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={false}
       >
         <b>{`${displayName} `}</b>
         {renderBody({
@@ -171,7 +171,7 @@ export function MNotice({ edited, content, renderBody, renderUrlsPreview }: MNot
       <MessageTextBody
         notice
         preWrap={typeof customBody !== 'string'}
-        jumboEmoji={JUMBO_EMOJI_REG.test(trimmedBody)}
+        jumboEmoji={isJumboEmoji(trimmedBody, trimmedCustomBody)}
       >
         {renderBody({
           body: trimmedBody,
diff --git a/src/app/components/message/layout/Base.tsx b/src/app/components/message/layout/Base.tsx
index aa5ffbf..549b6f4 100644
--- a/src/app/components/message/layout/Base.tsx
+++ b/src/app/components/message/layout/Base.tsx
@@ -32,10 +32,11 @@ export const MessageTextBody = as<'div', css.MessageTextBodyVariants & { notice?
   ({ as: asComp = 'div', className, preWrap, jumboEmoji, emote, notice, ...props }, ref) => (
     <Text
       as={asComp}
-      size="T400"
+      size={jumboEmoji ? 'Inherit' : 'T400'}
       priority={notice ? '300' : '400'}
       className={classNames(css.MessageTextBody({ preWrap, jumboEmoji, emote }), className)}
       data-allow-text-selection="true"
+      data-jumbo-emoji={jumboEmoji ? 'true' : undefined}
       {...props}
       ref={ref}
     />
diff --git a/src/app/components/message/layout/layout.css.ts b/src/app/components/message/layout/layout.css.ts
index 64d71fa..c1ff024 100644
--- a/src/app/components/message/layout/layout.css.ts
+++ b/src/app/components/message/layout/layout.css.ts
@@ -232,6 +232,9 @@ export const MessageTextBody = recipe({
       true: {
         fontSize: toRem(100),
         lineHeight: toRem(100),
+        // Don't clip oversized glyphs / custom emotes in jumbo mode
+        overflow: 'visible',
+        overflowY: 'visible',
       },
     },
     emote: {
@@ -245,24 +248,27 @@ export const MessageTextBody = recipe({
 
 export type MessageTextBodyVariants = RecipeVariants<typeof MessageTextBody>;
 
-const jumboEmojiClass = MessageTextBody.classNames.variants.jumboEmoji.true;
+// Prefer data-attr so sizing wins even if recipe class order fights folds Text sizes.
+const jumboEmojiSelector = '[data-jumbo-emoji="true"]';
 
-globalStyle(`${jumboEmojiClass} .${htmlCss.EmoticonBase}`, {
-  height: toRem(100),
-  padding: 0,
+globalStyle(`${jumboEmojiSelector} .${htmlCss.EmoticonBase}`, {
+  height: `${toRem(100)} !important`,
+  padding: '0 !important',
   verticalAlign: 'bottom',
 });
 
-globalStyle(`${jumboEmojiClass} .${htmlCss.Emoticon.classNames.base}`, {
-  fontSize: toRem(100),
-  height: toRem(100),
-  minWidth: toRem(100),
-  lineHeight: toRem(100),
-  top: 0,
+globalStyle(`${jumboEmojiSelector} .${htmlCss.Emoticon.classNames.base}`, {
+  fontSize: `${toRem(100)} !important`,
+  height: `${toRem(100)} !important`,
+  minWidth: `${toRem(100)} !important`,
+  lineHeight: `${toRem(100)} !important`,
+  top: '0 !important',
 });
 
-globalStyle(`${jumboEmojiClass} .${htmlCss.EmoticonImg}`, {
-  height: toRem(100),
-  width: toRem(100),
+globalStyle(`${jumboEmojiSelector} .${htmlCss.EmoticonImg}`, {
+  height: `${toRem(100)} !important`,
+  width: `${toRem(100)} !important`,
+  maxHeight: `${toRem(100)} !important`,
+  maxWidth: `${toRem(100)} !important`,
   objectFit: 'contain',
 });
diff --git a/src/app/plugins/react-custom-html-parser.tsx b/src/app/plugins/react-custom-html-parser.tsx
index da484bd..96aa9f8 100644
--- a/src/app/plugins/react-custom-html-parser.tsx
+++ b/src/app/plugins/react-custom-html-parser.tsx
@@ -552,10 +552,12 @@ export const getReactCustomHtmlParser = (
             );
           }
           if (htmlSrc && 'data-mx-emoticon' in props) {
+            // Drop presentational height/width so jumbo CSS can size freely
+            const { height: _h, width: _w, ...imgProps } = props;
             return (
               <span className={css.EmoticonBase}>
                 <span className={css.Emoticon()}>
-                  <AuthenticatedImg {...props} className={css.EmoticonImg} src={htmlSrc} />
+                  <AuthenticatedImg {...imgProps} className={css.EmoticonImg} src={htmlSrc} />
                 </span>
               </span>
             );
diff --git a/src/app/utils/regex.ts b/src/app/utils/regex.ts
index 0b98b0e..5a82a46 100644
--- a/src/app/utils/regex.ts
+++ b/src/app/utils/regex.ts
@@ -24,3 +24,28 @@ export const EMOJI_PATTERN = `[#*0-9]\uFE0F?\u20E3|[\xA9\xAE\u203C\u2049\u2122\u
 export const JUMBO_EMOJI_REG = new RegExp(
   `^(((${EMOJI_PATTERN})|(:.+?:))(${VARIATION_SELECTOR_PATTERN}|\\s)*){1,10}$`
 );
+
+/** Zero-width / format chars that break naive emoji-only matching. */
+const JUMBO_IGNORE_CHARS_REG = /[\u200B-\u200D\uFEFF\u00AD\u2060]/g;
+
+const ONLY_MX_EMOTICON_HTML_REG =
+  /^(?:\s|<br\s*\/?>)*((?:<img\b[^>]*\bdata-mx-emoticon\b[^>]*\/?>)(?:\s|<br\s*\/?>)*){1,10}$/i;
+
+/**
+ * True when a message is emoji/custom-emote only (Discord-style jumbo).
+ * Strips zero-width chars and also accepts HTML that is only mx-emoticon imgs.
+ */
+export const isJumboEmoji = (body: string, customBody?: string): boolean => {
+  const plain = body.replace(JUMBO_IGNORE_CHARS_REG, '').trim();
+  if (plain.length > 0 && JUMBO_EMOJI_REG.test(plain)) return true;
+
+  if (typeof customBody === 'string') {
+    const html = customBody
+      .replace(JUMBO_IGNORE_CHARS_REG, '')
+      .trim()
+      .replace(/(<br\s*\/?>\s*)+$/gi, '');
+    if (html.length > 0 && ONLY_MX_EMOTICON_HTML_REG.test(html)) return true;
+  }
+
+  return false;
+};