diff --git a/services/web/app/src/Features/Compile/CompileController.mjs b/services/web/app/src/Features/Compile/CompileController.mjs
index 41c2cf42ae..12609b055d 100644
--- a/services/web/app/src/Features/Compile/CompileController.mjs
+++ b/services/web/app/src/Features/Compile/CompileController.mjs
@@ -1,6 +1,7 @@
 import { pipeline } from 'node:stream/promises'
 import Metrics from '@overleaf/metrics'
 import ProjectGetter from '../Project/ProjectGetter.mjs'
+import { Project } from '../models/Project.mjs'
 import CompileManager from './CompileManager.mjs'
 import ClsiManager from './ClsiManager.mjs'
 import logger from '@overleaf/logger'
@@ -300,6 +301,16 @@ const _CompileController = {
       ? getOutputFilesArchiveSpecification(projectId, userId, buildId)
       : null
 
+    // Persist quarto output flavor so the project-list badge can distinguish
+    // RevealJS presentations from PDF documents without needing a compile.
+    if (status === 'success' && options.compiler === 'quarto') {
+      const isHtml = outputFiles.some(f => f.path === 'output.html')
+      Project.updateOne(
+        { _id: projectId },
+        { quartoFlavor: isHtml ? 'revealjs' : 'pdf' }
+      ).exec().catch(() => {})
+    }
+
     res.json({
       status,
       outputFiles,
diff --git a/services/web/app/src/Features/Project/ProjectListController.mjs b/services/web/app/src/Features/Project/ProjectListController.mjs
index e65138186a..a298ea74a0 100644
--- a/services/web/app/src/Features/Project/ProjectListController.mjs
+++ b/services/web/app/src/Features/Project/ProjectListController.mjs
@@ -681,7 +681,7 @@ async function _getProjects(
   const results = await Promise.all([
     ProjectGetter.promises.findAllUsersProjects(
       userId,
-      'name lastUpdated lastUpdatedBy publicAccesLevel archived trashed owner_ref tokens compiler'
+      'name lastUpdated lastUpdatedBy publicAccesLevel archived trashed owner_ref tokens compiler quartoFlavor'
     ),
     TagsHandler.promises.getAllTags(userId),
   ])
@@ -826,6 +826,7 @@ function _formatProjectInfo(project, accessLevel, source, userId) {
     archived,
     trashed,
     compiler: project.compiler,
+    quartoFlavor: project.quartoFlavor,
   }
 }
 
@@ -880,6 +881,7 @@ async function _injectProjectUsers(projects) {
         : users[project.owner_ref.toString()],
     owner_ref: undefined,
     compiler: project.compiler,
+    quartoFlavor: project.quartoFlavor,
   }))
 }
 
diff --git a/services/web/app/src/models/Project.mjs b/services/web/app/src/models/Project.mjs
index ffa49dc6ed..8415fb4fda 100644
--- a/services/web/app/src/models/Project.mjs
+++ b/services/web/app/src/models/Project.mjs
@@ -38,6 +38,7 @@ export const ProjectSchema = new Schema(
     version: { type: Number }, // incremented for every change in the project structure (folders and filenames)
     publicAccesLevel: { type: String, default: 'private' },
     compiler: { type: String, default: settings.defaultLatexCompiler },
+    quartoFlavor: { type: String, enum: ['revealjs', 'pdf', null] },
     spellCheckLanguage: { type: String, default: 'en' },
     deletedByExternalDataSource: { type: Boolean, default: false },
     description: { type: String, default: '' },
diff --git a/services/web/frontend/js/features/project-list/components/table/cells/format-cell.tsx b/services/web/frontend/js/features/project-list/components/table/cells/format-cell.tsx
index 213cf3b8bf..604c3323de 100644
--- a/services/web/frontend/js/features/project-list/components/table/cells/format-cell.tsx
+++ b/services/web/frontend/js/features/project-list/components/table/cells/format-cell.tsx
@@ -4,13 +4,19 @@ import { ProjectCompiler } from '../../../../../../../types/project-settings'
 // Map the stored compiler engine to the document format the project produces.
 // CLSI dispatches the real engine from the root file's extension, but the
 // compiler field is a faithful, cheap proxy for the project's format.
-function formatLabel(compiler: ProjectCompiler | undefined): {
+function formatLabel(
+  compiler: ProjectCompiler | undefined,
+  quartoFlavor: 'revealjs' | 'pdf' | undefined
+): {
   label: string
-  variant: 'quarto' | 'typst' | 'latex'
+  variant: 'quarto-slides' | 'quarto' | 'typst' | 'latex'
 } {
   switch (compiler) {
     case 'quarto':
-      return { label: 'Quarto', variant: 'quarto' }
+      if (quartoFlavor === 'revealjs') {
+        return { label: 'Quarto Slides', variant: 'quarto-slides' }
+      }
+      return { label: 'Quarto PDF', variant: 'quarto' }
     case 'typst':
       return { label: 'Typst', variant: 'typst' }
     default:
@@ -24,7 +30,7 @@ type FormatCellProps = {
 }
 
 export default function FormatCell({ project }: FormatCellProps) {
-  const { label, variant } = formatLabel(project.compiler)
+  const { label, variant } = formatLabel(project.compiler, project.quartoFlavor)
 
   return (
     <span
diff --git a/services/web/frontend/stylesheets/pages/project-list.scss b/services/web/frontend/stylesheets/pages/project-list.scss
index dc4c58594a..ce8363f47a 100644
--- a/services/web/frontend/stylesheets/pages/project-list.scss
+++ b/services/web/frontend/stylesheets/pages/project-list.scss
@@ -407,7 +407,11 @@ ul.project-list-filters {
     white-space: nowrap;
 
     &.project-format-badge-quarto {
-      background-color: #447099;
+      background-color: #447099; // Quarto blue (PDF output)
+    }
+
+    &.project-format-badge-quarto-slides {
+      background-color: #7e56c2; // purple — presentation feel, blends Quarto + RevealJS
     }
 
     &.project-format-badge-typst {
diff --git a/services/web/types/project/dashboard/api.d.ts b/services/web/types/project/dashboard/api.d.ts
index d537247f69..b123c8a4b0 100644
--- a/services/web/types/project/dashboard/api.d.ts
+++ b/services/web/types/project/dashboard/api.d.ts
@@ -53,6 +53,7 @@ export type ProjectApi = {
   accessLevel: ProjectAccessLevel
   source: Source
   compiler?: ProjectCompiler
+  quartoFlavor?: 'revealjs' | 'pdf'
 }
 
 export type Project = MergeAndOverride<