diff --git a/app/services/tiptap_service.rb b/app/services/tiptap_service.rb
new file mode 100644
index 000000000..9514dc11c
--- /dev/null
+++ b/app/services/tiptap_service.rb
@@ -0,0 +1,65 @@
+class TiptapService
+  class << self
+    def to_html(node, tags)
+      children(node[:content], tags)
+    end
+
+    private
+
+    def children(content, tags)
+      content.map { node_to_html(_1, tags) }.join
+    end
+
+    def node_to_html(node, tags)
+      case node
+      in type: 'paragraph', content:, **rest
+        "<p#{text_align(rest[:attrs])}>#{children(content, tags)}</p>"
+      in type: 'heading', attrs: { level:, **attrs }, content:
+        "<h#{level}#{text_align(attrs)}>#{children(content, tags)}</h#{level}>"
+      in type: 'bulletList', content:
+        "<ul>#{children(content, tags)}</ul>"
+      in type: 'orderedList', content:
+        "<ol>#{children(content, tags)}</ol>"
+      in type: 'listItem', content:
+        "<li>#{children(content, tags)}</li>"
+      in type: 'text', text:, **rest
+        if rest[:marks].present?
+          apply_marks(text, rest[:marks])
+        else
+          text
+        end
+      in type: 'mention', attrs: { id: }, **rest
+        if rest[:marks].present?
+          apply_marks(tags[id], rest[:marks])
+        else
+          tags[id]
+        end
+      end
+    end
+
+    def text_align(attrs)
+      if attrs.present? && attrs[:textAlign].present?
+        " style=\"text-align: #{attrs[:textAlign]}\""
+      else
+        ""
+      end
+    end
+
+    def apply_marks(text, marks)
+      marks.reduce(text) do |text, mark|
+        case mark
+        in type: 'bold'
+          "<strong>#{text}</strong>"
+        in type: 'italic'
+          "<em>#{text}</em>"
+        in type: 'underline'
+          "<u>#{text}</u>"
+        in type: 'strike'
+          "<s>#{text}</s>"
+        in type: 'highlight'
+          "<mark>#{text}</mark>"
+        end
+      end
+    end
+  end
+end
diff --git a/spec/services/tiptap_service_spec.rb b/spec/services/tiptap_service_spec.rb
new file mode 100644
index 000000000..37cdd6d0c
--- /dev/null
+++ b/spec/services/tiptap_service_spec.rb
@@ -0,0 +1,142 @@
+RSpec.describe TiptapService do
+  describe '.to_html' do
+    let(:json) do
+      {
+        type: 'doc',
+        content: [
+          {
+            type: 'paragraph',
+            attrs: { textAlign: 'right' },
+            content: [
+              {
+                type: 'text',
+                text: 'Hello world!'
+              }
+            ]
+          },
+          {
+            type: 'paragraph',
+            content: [
+              {
+                type: 'text',
+                text: 'Bonjour ',
+                marks: [{ type: 'italic' }, { type: 'strike' }]
+              },
+              {
+                type: 'mention',
+                attrs: { id: 'name' },
+                marks: [{ type: 'bold' }, { type: 'underline' }]
+              },
+              {
+                type: 'text',
+                text: ' '
+              },
+              {
+                type: 'text',
+                text: '!',
+                marks: [{ type: 'highlight' }]
+              }
+            ]
+          },
+          {
+            type: 'heading',
+            attrs: { level: 1 },
+            content: [{ type: 'text', text: 'Heading 1' }]
+          },
+          {
+            type: 'heading',
+            attrs: { level: 2, textAlign: 'center' },
+            content: [{ type: 'text', text: 'Heading 2' }]
+          },
+          {
+            type: 'heading',
+            attrs: { level: 3 },
+            content: [{ type: 'text', text: 'Heading 3' }]
+          },
+          {
+            type: 'bulletList',
+            content: [
+              {
+                type: 'listItem',
+                content: [
+                  {
+                    type: 'paragraph',
+                    content: [
+                      {
+                        type: 'text',
+                        text: 'Item 1'
+                      }
+                    ]
+                  }
+                ]
+              },
+              {
+                type: 'listItem',
+                content: [
+                  {
+                    type: 'paragraph',
+                    content: [
+                      {
+                        type: 'text',
+                        text: 'Item 2'
+                      }
+                    ]
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            type: 'orderedList',
+            content: [
+              {
+                type: 'listItem',
+                content: [
+                  {
+                    type: 'paragraph',
+                    content: [
+                      {
+                        type: 'text',
+                        text: 'Item 1'
+                      }
+                    ]
+                  }
+                ]
+              },
+              {
+                type: 'listItem',
+                content: [
+                  {
+                    type: 'paragraph',
+                    content: [
+                      {
+                        type: 'text',
+                        text: 'Item 2'
+                      }
+                    ]
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      }
+    end
+    let(:tags) { { 'name' => 'Paul' } }
+    let(:html) do
+      [
+        '<p style="text-align: right">Hello world!</p>',
+        '<p><s><em>Bonjour </em></s><u><strong>Paul</strong></u> <mark>!</mark></p>',
+        '<h1>Heading 1</h1>',
+        '<h2 style="text-align: center">Heading 2</h2>',
+        '<h3>Heading 3</h3>',
+        '<ul><li><p>Item 1</p></li><li><p>Item 2</p></li></ul>',
+        '<ol><li><p>Item 1</p></li><li><p>Item 2</p></li></ol>'
+      ].join
+    end
+
+    it 'returns html' do
+      expect(described_class.to_html(json, tags)).to eq(html)
+    end
+  end
+end