diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a58ce89a7b..7199486e91 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -100,6 +100,17 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Set up Python ${{ env.PYTHON_VERSION }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: "${{ env.PYTHON_VERSION }}"
+
+      - name: Upgrade pip
+        run: pip install --upgrade pip
+
+      - name: Install cairosvg dependency
+        run: pip install cairosvg
+
       - name: Set up NodeJS ${{ env.NODE_VERSION }}
         uses: actions/setup-node@v4
         with:
diff --git a/Gulpfile.js b/Gulpfile.js
index 9e0611dcc7..923e36301c 100644
--- a/Gulpfile.js
+++ b/Gulpfile.js
@@ -6,6 +6,7 @@ const { ESLint } = require('eslint')
 const gulp = require('gulp')
 const gulpif = require('gulp-if')
 const imagemin = require('gulp-imagemin')
+const run = require('gulp-run')
 const options = require('gulp-options')
 const path = require('path')
 const postcss = require('gulp-postcss')
@@ -200,6 +201,17 @@ function images() {
     .pipe(gulp.dest('dist/'))
 }
 
+// Generate PNG versions of SVG smileys.
+// Output files are not optimized for size.
+function convertSmileysToPng() {
+  const pathToScript = 'scripts/convert_smileys_to_png.py'
+  const pathToSvgSmileys = 'assets/smileys/svg/'
+  const pathToPngSmileys = 'dist/smileys/png'
+  const convertToPng = run(`python ${pathToScript} ${pathToSvgSmileys} ${pathToPngSmileys}`)
+  convertToPng.exec()
+  return Promise.resolve('Smileys were converted') // to fit into gulp's asynchronous system
+}
+
 function spriteImages() {
   return gulp.src(['dist/images/sprite*.png'])
     .pipe(gulpif(!fast, imagemin())) // Minify the images
@@ -239,7 +251,27 @@ function watch() {
 }
 
 // Build the front
-const build = gulp.parallel(prepareZmd, prepareEasyMde, jsPackages, js, images, errors, gulp.series(spriteCss, gulp.parallel(cssPackages, css, spriteImages)), iconFonts, textFonts)
+const build = gulp.series(
+  convertSmileysToPng, // automatically converted files may be overwritten with manually converted files afterwards
+  gulp.parallel(
+    prepareZmd,
+    prepareEasyMde,
+    jsPackages,
+    js,
+    images,
+    errors,
+    gulp.series(
+      spriteCss,
+      gulp.parallel(
+        cssPackages,
+        css,
+        spriteImages
+      )
+    ),
+    iconFonts,
+    textFonts
+  )
+)
 
 exports.build = build
 exports.watch = gulp.series(build, watch)
diff --git a/assets/smileys/png/ninja.png b/assets/smileys/png/ninja.png
new file mode 100644
index 0000000000..10d7542973
Binary files /dev/null and b/assets/smileys/png/ninja.png differ
diff --git a/package.json b/package.json
index 7759db781e..2918cd6634 100644
--- a/package.json
+++ b/package.json
@@ -42,6 +42,7 @@
     "gulp-imagemin": "7.1.0",
     "gulp-options": "1.1.1",
     "gulp-postcss": "10.0.0",
+    "gulp-run": "1.7.1",
     "gulp-terser-js": "5.2.2",
     "gulp.spritesmith": "6.13.1",
     "jdenticon": "3.3.0",
diff --git a/scripts/convert_smileys_to_png.py b/scripts/convert_smileys_to_png.py
new file mode 100644
index 0000000000..a854f970da
--- /dev/null
+++ b/scripts/convert_smileys_to_png.py
@@ -0,0 +1,57 @@
+"""
+Convert smileys from SVG to PNG.
+
+In our codebase, the reference format for smileys is SVG. However, some epub readers cannot display SVGs,
+and we have chosen to fall back to PNG so that images are displayed properly with most epub readers.
+In order to avoid manual generation of PNG versions, we convert them automatically from the reference SVG files.
+
+This file provide tools to perform the conversion using a CLI interface.
+It relies on cairosvg to perform the file conversion.
+"""
+
+import argparse
+import os
+import pathlib
+
+import cairosvg
+
+
+def convert_folder_to_png(src_folder: pathlib.Path, dst_folder: pathlib.Path) -> int:
+    """
+    Convert all SVGs from src_folder into PNGs and write them in dst_folder.
+    Create dst_folder if needed.
+    Existing files in dst_folder are overwritten.
+    Return the number of converted files.
+    """
+    src_files = src_folder.rglob("*.svg")
+    os.makedirs(dst_folder, exist_ok=True)
+    converted_file_count = 0
+    for src_file in src_files:
+        dst_file = dst_folder / f"{src_file.stem}.png"
+        cairosvg.svg2png(url=src_file.as_posix(), write_to=dst_file.as_posix())
+        converted_file_count += 1
+    return converted_file_count
+
+
+def get_cli_args():
+    """Get arguments from the CLI."""
+
+    # Build parser
+    parser = argparse.ArgumentParser(description="Convert a folder of SVG files to PNG")
+    parser.add_argument("source", help="Folder containing the SVG files to be converted")
+    parser.add_argument("destination", help="Folder in which the PNG files are written")
+
+    # Parse
+    raw_args = parser.parse_args()
+    processed_args = {
+        "source": pathlib.Path(raw_args.source),
+        "destination": pathlib.Path(raw_args.destination),
+    }
+
+    return processed_args
+
+
+if __name__ == "__main__":
+    args = get_cli_args()
+    file_count = convert_folder_to_png(args["source"], args["destination"])
+    print(f"{__file__}: {file_count} files converted.")