diff --git a/app/javascript/controllers/file_preview_controller.js b/app/javascript/controllers/file_preview_controller.js
new file mode 100644
index 00000000..9eaaab2d
--- /dev/null
+++ b/app/javascript/controllers/file_preview_controller.js
@@ -0,0 +1,19 @@
+import { Controller } from 'stimulus'
+import bsCustomFileInput from "bs-custom-file-input";
+
+document.addEventListener("turbolinks:load", () => {
+  bsCustomFileInput.init();
+});
+
+export default class extends Controller {
+  static targets = ["preview", "input"];
+
+  connect() {
+  }
+
+  update(event = undefined) {
+    if (!this.hasPreviewTarget) return;
+
+    this.previewTarget.src = window.URL.createObjectURL(this.inputTarget.files[0])
+  }
+}
diff --git a/app/javascript/etc/image_preview.js b/app/javascript/etc/image_preview.js
deleted file mode 100644
index fcdeec85..00000000
--- a/app/javascript/etc/image_preview.js
+++ /dev/null
@@ -1,11 +0,0 @@
-document.addEventListener('turbolinks:load', () => {
-  document.querySelectorAll('input[type=file]').forEach(file => {
-    if (!file.dataset.preview) return
-
-    file.addEventListener('change', event => {
-      if (file.files.length === 0) return
-
-      document.querySelector('#' + file.dataset.preview).src = window.URL.createObjectURL(file.files[0])
-    })
-  })
-})
diff --git a/app/javascript/etc/index.js b/app/javascript/etc/index.js
index 9ee6a95a..3a1ef75c 100644
--- a/app/javascript/etc/index.js
+++ b/app/javascript/etc/index.js
@@ -1,5 +1,4 @@
 import './external_links'
-import './image_preview'
 import './input-date'
 import './input-tag'
 import './prosemirror'
diff --git a/app/views/posts/attributes/_file.haml b/app/views/posts/attributes/_file.haml
index 54f9f81a..20c27399 100644
--- a/app/views/posts/attributes/_file.haml
+++ b/app/views/posts/attributes/_file.haml
@@ -1,12 +1,14 @@
-.form-group
+.form-group{ data: { controller: 'file-preview' } }
   - if metadata.static_file
     - case metadata.static_file.blob.content_type
       - when %r{\Avideo/}
         = video_tag url_for(metadata.static_file),
-          controls: true, class: 'img-fluid'
+          controls: true, class: 'img-fluid',
+          data: { target: 'file-preview.preview' }
       - when %r{\Aaudio/}
         = audio_tag url_for(metadata.static_file),
-          controls: true, class: 'img-fluid'
+          controls: true, class: 'img-fluid',
+          data: { target: 'file-preview.preview' }
       - when 'application/pdf'
         %iframe{ src: url_for(metadata.static_file) }
       - else
@@ -24,7 +26,7 @@
     = file_field(*field_name_for(base, attribute, :path),
       **field_options(attribute, metadata, required: (metadata.required && !metadata.path?)),
       class: "custom-file-input #{invalid(post, attribute)}",
-      data: { preview: "#{attribute}-preview" })
+      data: { target: 'file-preview.input', action: 'file-preview#update' })
     = label_tag "#{base}_#{attribute}_path",
       post_label_t(attribute, :path, post: post), class: 'custom-file-label'
     = render 'posts/attribute_feedback',
diff --git a/app/views/posts/attributes/_image.haml b/app/views/posts/attributes/_image.haml
index 84fe56fd..241a78e8 100644
--- a/app/views/posts/attributes/_image.haml
+++ b/app/views/posts/attributes/_image.haml
@@ -1,9 +1,9 @@
-.form-group
+.form-group{ data: { controller: 'file-preview' } }
   - if metadata.static_file
     = image_tag url_for(metadata.static_file),
       alt: metadata.value['description'],
       class: 'img-fluid',
-      id: "#{attribute}-preview"
+      data: { target: 'file-preview.preview' }
 
     -# Mantener el valor si no enviamos ninguna imagen
     = hidden_field_tag "#{base}[#{attribute}][path]", metadata.value['path']
@@ -16,13 +16,14 @@
     = image_tag '',
       alt: metadata.value['description'],
       class: 'img-fluid',
-      id: "#{attribute}-preview"
+      data: { target: 'file-preview.preview' }
 
   .custom-file
     = file_field(*field_name_for(base, attribute, :path),
       **field_options(attribute, metadata, required: (metadata.required && !metadata.path?)),
       class: "custom-file-input #{invalid(post, attribute)}",
-      accept: ActiveStorage.web_image_content_types.join(','), data: { preview: "#{attribute}-preview" })
+      accept: ActiveStorage.web_image_content_types.join(','),
+      data: { target: 'file-preview.input', action: 'file-preview#update' })
     = label_tag "#{base}_#{attribute}_path",
       post_label_t(attribute, :path, post: post), class: 'custom-file-label'
     = render 'posts/attribute_feedback',
diff --git a/config/initializers/content_security_policy.rb b/config/initializers/content_security_policy.rb
index 91d287e0..c07c7751 100644
--- a/config/initializers/content_security_policy.rb
+++ b/config/initializers/content_security_policy.rb
@@ -7,7 +7,7 @@
 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
 
 Rails.application.config.content_security_policy do |policy|
-  policy.default_src :self
+  policy.default_src :self, :blob
   # XXX: Varios scripts generan estilos en línea
   policy.style_src   :self, :unsafe_inline, :https
   # Repetimos la default para poder saber cuál es la política en falta
diff --git a/package.json b/package.json
index 74ff491a..eea0473f 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,7 @@
     "@rails/webpacker": "5.4.4",
     "@suttyweb/editor": "^0.1.27",
     "babel-loader": "^8.2.2",
+    "bs-custom-file-input": "^1.3.4",
     "chart.js": "^3.5.1",
     "chartkick": "^4.0.5",
     "circular-dependency-plugin": "^5.2.2",
diff --git a/yarn.lock b/yarn.lock
index 829b7ed1..7a81a221 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2699,6 +2699,11 @@ browserslist@^4.22.2:
     node-releases "^2.0.14"
     update-browserslist-db "^1.0.13"
 
+bs-custom-file-input@^1.3.4:
+  version "1.3.4"
+  resolved "https://registry.yarnpkg.com/bs-custom-file-input/-/bs-custom-file-input-1.3.4.tgz#c275cb8d4f1c02ba026324292509fa9a747dbda8"
+  integrity sha512-NBsQzTnef3OW1MvdKBbMHAYHssCd613MSeJV7z2McXznWtVMnJCy7Ckyc+PwxV6Pk16cu6YBcYWh/ZE0XWNKCA==
+
 buffer-from@^1.0.0:
   version "1.1.1"
   resolved "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.1.tgz"