diff --git a/.changeset/proud-seahorses-wash.md b/.changeset/proud-seahorses-wash.md
index 0c7e947cd..3384f28e9 100644
--- a/.changeset/proud-seahorses-wash.md
+++ b/.changeset/proud-seahorses-wash.md
@@ -2,4 +2,4 @@
 'mermaid': patch
 ---
 
-Free fontawesome icons are now embeded as svg inside diagram. Pro icons will still be using <i> tag.
+Registered icons are now embedded as SVGs inside diagram. If an icon is not available in the registered icons it will still use <i> tag
diff --git a/cypress/integration/rendering/flowchart-icon.spec.js b/cypress/integration/rendering/flowchart-icon.spec.js
new file mode 100644
index 000000000..be7dd7b70
--- /dev/null
+++ b/cypress/integration/rendering/flowchart-icon.spec.js
@@ -0,0 +1,32 @@
+import { imgSnapshotTest } from '../../helpers/util.ts';
+
+const themes = ['default', 'forest', 'dark', 'base', 'neutral'];
+
+themes.forEach((theme, index) => {
+  describe('Flowchart Icon', () => {
+    it(`${index + 1}-icon: verify if icons are working from fontawesome library ${theme} theme`, () => {
+      imgSnapshotTest(
+        `flowchart TD
+            A("fab:fa-twitter Twitter") --> B("fab:fa-facebook Facebook")
+            B --> C("fa:fa-coffee Coffee")
+            C --> D("fa:fa-car Car")
+            D --> E("fab:fa-github GitHub")
+        `,
+        { theme }
+      );
+    });
+  });
+});
+
+themes.forEach((theme, index) => {
+  describe('Flowchart Icon', () => {
+    it(`${index + 1}-icon: verify if registered icons are working on ${theme} theme`, () => {
+      imgSnapshotTest(
+        `flowchart TD
+            A("fa:fa-bell Bell") 
+        `,
+        { theme }
+      );
+    });
+  });
+});
diff --git a/cypress/platform/e2e.html b/cypress/platform/e2e.html
index d80caf7a4..7418da094 100644
--- a/cypress/platform/e2e.html
+++ b/cypress/platform/e2e.html
@@ -6,6 +6,10 @@
       href="https://fonts.googleapis.com/css?family=Noto+Sans+SC&display=swap"
       rel="stylesheet"
     />
+    <link
+      rel="stylesheet"
+      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.7.2/css/all.min.css"
+    />
     <style>
       svg {
         border: 2px solid darkred;
diff --git a/cypress/platform/viewer.js b/cypress/platform/viewer.js
index a9d4d2d81..ffecf3bbd 100644
--- a/cypress/platform/viewer.js
+++ b/cypress/platform/viewer.js
@@ -51,7 +51,7 @@ const contentLoaded = async function () {
     mermaid.registerLayoutLoaders(layouts);
     mermaid.initialize(graphObj.mermaid);
     const staticBellIconPack = {
-      prefix: 'fa6-regular',
+      prefix: 'fa',
       icons: {
         bell: {
           body: '<path fill="currentColor" d="M224 0c-17.7 0-32 14.3-32 32v19.2C119 66 64 130.6 64 208v25.4c0 45.4-15.5 89.5-43.8 124.9L5.3 377c-5.8 7.2-6.9 17.1-2.9 25.4S14.8 416 24 416h400c9.2 0 17.6-5.3 21.6-13.6s2.9-18.2-2.9-25.4l-14.9-18.6c-28.3-35.5-43.8-79.6-43.8-125V208c0-77.4-55-142-128-156.8V32c0-17.7-14.3-32-32-32m0 96c61.9 0 112 50.1 112 112v25.4c0 47.9 13.9 94.6 39.7 134.6H72.3c25.8-40 39.7-86.7 39.7-134.6V208c0-61.9 50.1-112 112-112m64 352H160c0 17 6.7 33.3 18.7 45.3S207 512 224 512s33.3-6.7 45.3-18.7S288 465 288 448"/>',
diff --git a/docs/syntax/flowchart.md b/docs/syntax/flowchart.md
index 40ee2ef63..a7b9738d9 100644
--- a/docs/syntax/flowchart.md
+++ b/docs/syntax/flowchart.md
@@ -1916,9 +1916,13 @@ If a class is named default it will be assigned to all classes without specific
 
 ## Basic support for fontawesome
 
-It is possible to add icons from fontawesome.
+It is possible to add icons from fontawesome and registered icon pack.
 
-The icons are accessed via the syntax fa:#icon class name#.
+Mermaid supports icons from registered icon packs. Follow the instructions provided [here](../config/icons.md) to register your icon packs.
+
+The registered icons can be accessed via the syntax #registered icon pack name#:#icon name#.
+
+The fontawesome icons are accessed via the syntax fa:#icon class name#.
 
 ```mermaid-example
 flowchart TD
diff --git a/packages/mermaid/src/docs/syntax/flowchart.md b/packages/mermaid/src/docs/syntax/flowchart.md
index 2ddad4795..0ee5f39d6 100644
--- a/packages/mermaid/src/docs/syntax/flowchart.md
+++ b/packages/mermaid/src/docs/syntax/flowchart.md
@@ -1231,9 +1231,13 @@ If a class is named default it will be assigned to all classes without specific
 
 ## Basic support for fontawesome
 
-It is possible to add icons from fontawesome.
+It is possible to add icons from fontawesome and registered icon pack.
 
-The icons are accessed via the syntax fa:#icon class name#.
+Mermaid supports icons from registered icon packs. Follow the instructions provided [here](../config/icons.md) to register your icon packs.
+
+The registered icons can be accessed via the syntax #registered icon pack name#:#icon name#.
+
+The fontawesome icons are accessed via the syntax fa:#icon class name#.
 
 ```mermaid-example
 flowchart TD
diff --git a/packages/mermaid/src/rendering-util/createText.spec.ts b/packages/mermaid/src/rendering-util/createText.spec.ts
index c99ae2b58..60912da2a 100644
--- a/packages/mermaid/src/rendering-util/createText.spec.ts
+++ b/packages/mermaid/src/rendering-util/createText.spec.ts
@@ -6,7 +6,7 @@ describe('replaceIconSubstring', () => {
   it('converts FontAwesome icon notations to HTML tags', async () => {
     const input = 'This is an icon: fa:fa-user and fab:fa-github';
     const output = await replaceIconSubstring(input);
-    const expected = `This is an icon: <i class='fa fa-user'></i> and <i class='fa-brands fa-github'></i>`;
+    const expected = `This is an icon: <i class='fa fa-user'></i> and <i class='fab fa-github'></i>`;
     expect(output).toEqual(expected);
   });
 
@@ -19,7 +19,7 @@ describe('replaceIconSubstring', () => {
   it('correctly processes multiple FontAwesome icon notations in one string', async () => {
     const input = 'Icons galore: fa:fa-arrow-right, fak:fa-truck, fas:fa-home';
     const output = await replaceIconSubstring(input);
-    const expected = `Icons galore: <i class='fa fa-arrow-right'></i>, <i class='fak fa-truck'></i>, <i class='fa-solid fa-home'></i>`;
+    const expected = `Icons galore: <i class='fa fa-arrow-right'></i>, <i class='fak fa-truck'></i>, <i class='fas fa-home'></i>`;
     expect(output).toEqual(expected);
   });
 
@@ -33,7 +33,7 @@ describe('replaceIconSubstring', () => {
 
   it('correctly process the registered icons', async () => {
     const staticBellIconPack = {
-      prefix: 'fa6-regular',
+      prefix: 'fa',
       icons: {
         bell: {
           body: '<path fill="currentColor" d="M224 0c-17.7 0-32 14.3-32 32v19.2C119 66 64 130.6 64 208v25.4c0 45.4-15.5 89.5-43.8 124.9L5.3 377c-5.8 7.2-6.9 17.1-2.9 25.4S14.8 416 24 416h400c9.2 0 17.6-5.3 21.6-13.6s2.9-18.2-2.9-25.4l-14.9-18.6c-28.3-35.5-43.8-79.6-43.8-125V208c0-77.4-55-142-128-156.8V32c0-17.7-14.3-32-32-32m0 96c61.9 0 112 50.1 112 112v25.4c0 47.9 13.9 94.6 39.7 134.6H72.3c25.8-40 39.7-86.7 39.7-134.6V208c0-61.9 50.1-112 112-112m64 352H160c0 17 6.7 33.3 18.7 45.3S207 512 224 512s33.3-6.7 45.3-18.7S288 465 288 448"/>',
diff --git a/packages/mermaid/src/rendering-util/createText.ts b/packages/mermaid/src/rendering-util/createText.ts
index c45255fe2..676d45907 100644
--- a/packages/mermaid/src/rendering-util/createText.ts
+++ b/packages/mermaid/src/rendering-util/createText.ts
@@ -181,19 +181,12 @@ function updateTextContentAndStyles(tspan: any, wrappedLine: MarkdownWord[]) {
 /**
  * Convert fontawesome labels into fontawesome icons by using a regex pattern
  * @param text - The raw string to convert
- * @returns string with fontawesome icons as i tags if they are from pro pack and as svg if they are from free pack
+ * @returns string with fontawesome icons as svg if the icon is registered otherwise as i tags
  */
-export async function replaceIconSubstring(text) {
-  const iconRegex = /(fas|fab|far|fa|fal|fak|fad):fa-([a-z-]+)/g;
-  const classNameMap = {
-    fas: 'fa-solid',
-    fab: 'fa-brands',
-    far: 'fa-regular',
-    fa: 'fa',
-    fal: 'fa-light',
-    fad: 'fa-duotone',
-    fak: 'fak',
-  } as const;
+export async function replaceIconSubstring(text: string) {
+  // The letters 'bklrs' stand for possible endings of the fontawesome prefix (e.g. 'fab' for brands, 'fak' for fa-kit) // cspell: disable-line
+  const iconRegex = /(fa[bklrs]?):fa-([\w-]+)/g; // cspell: disable-line
+
   const matches = [...text.matchAll(iconRegex)];
   if (matches.length === 0) {
     return text;
@@ -203,19 +196,14 @@ export async function replaceIconSubstring(text) {
 
   for (const match of matches) {
     const [fullMatch, prefix, iconName] = match;
-    const className = classNameMap[prefix];
     const registeredIconName = `${prefix}:${iconName}`;
-
     try {
-      const isFreeIcon = await isIconAvailable(registeredIconName);
-      if (!isFreeIcon) {
-        log.warn(`Icon ${registeredIconName} is a pro icon.`);
-        newText = newText.replace(fullMatch, `<i class='${className} fa-${iconName}'></i>`);
-        continue;
-      }
-      const faIcon = await getIconSVG(registeredIconName, undefined, { class: 'label-icon' });
-      if (faIcon) {
+      const isIconAvail = await isIconAvailable(registeredIconName);
+      if (isIconAvail) {
+        const faIcon = await getIconSVG(registeredIconName, undefined, { class: 'label-icon' });
         newText = newText.replace(fullMatch, faIcon);
+      } else {
+        newText = newText.replace(fullMatch, `<i class='${fullMatch.replace(':', ' ')}'></i>`);
       }
     } catch (error) {
       log.error(`Error processing ${registeredIconName}:`, error);