diff --git a/photologue_custom/management/commands/duplicate.py b/photologue_custom/management/commands/duplicate.py
new file mode 100644
index 0000000..c9fd70a
--- /dev/null
+++ b/photologue_custom/management/commands/duplicate.py
@@ -0,0 +1,71 @@
+from django.core.management.base import BaseCommand, CommandError
+from photologue_custom.models import Gallery
+
+import hashlib
+
+
+class Command(BaseCommand):
+    help = 'List all duplicate for chosen galleries'
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            '--slugs', nargs='+', help='Try to find duplicate in the selected galleries', default=[])
+        parser.add_argument('-a', '--all', action='store_true',
+                            help='Try to find duplicate in all galleries, overide any slugs given')
+        parser.add_argument('-d', '--delete', action='store_true')
+
+    def handle(self, *args, **options):
+        # Collect all required galleries
+        if options['all']:
+            galleries = Gallery.objects.all()
+        else:
+            for slug in options['slugs']:
+                for gallery in Gallery.objects.all():
+                    if gallery.slug == slug:
+                        galleries += [gallery]
+                        break
+                else:
+                    raise CommandError(
+                        'Slug {} does not correspond to a gallery in the database.'.format(slug))
+                    print('error')
+        # Find duplicates in all galleries
+        for gallery in galleries:
+            duplicates = find_duplicate(gallery)
+            self.stdout.write('Gallery {} :'.format(gallery.slug))
+            for (original, copies) in duplicates:
+                self.stdout.write(
+                    '  {} has following duplicate(s) :'.format(original.slug))
+                for copy in copies:
+                    self.stdout.write('    {}'.format(copy.slug))
+            # Delete them if --delete
+            if options['delete']:
+                self.stdout.write(
+                    '  Deleting duplicate in {} :'.format(gallery.slug))
+                for (_original, copies) in duplicates:
+                    for copy in copies:
+                        self.stdout.write(
+                            '    Deleting {}...'.format(copy.slug))
+                        copy.delete()
+
+
+def find_duplicate(gallery):
+    # Dict of all already checked photos
+    non_duplicate = {}
+    # Dict of all found duplicate {h0 : (original:[duplicates])}
+    duplicate = {}
+
+    for photo in gallery.photos.all():
+        h0 = hashlib.sha256(photo.image.read()).digest()
+        if h0 not in non_duplicate:
+            # Photo is not a duplicate
+            non_duplicate[h0] = photo
+        elif h0 in duplicate:
+            if len(photo.slug) > len(duplicate[h0][0].slug):
+                duplicate[h0][1] += [photo]
+            else:
+                duplicate[h0][1] += [duplicate[h0][0]]
+                duplicate[h0][0] = photo
+        else:
+            duplicate[h0] = [non_duplicate[h0], [photo]]
+    # Return only value because hash aren't usefull
+    return duplicate.values()