diff --git a/generate_emoji_thumbnails.py b/generate_emoji_thumbnails.py
new file mode 100755
index 000000000..8ca9d4523
--- /dev/null
+++ b/generate_emoji_thumbnails.py
@@ -0,0 +1,141 @@
+#!/usr/bin/env python
+# Copyright 2017 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Generate 72x72 thumbnails including aliases.
+
+Takes a source directory of images named using our emoji filename
+conventions and writes thumbnails of them into the destination
+directory.  If a file is a target of one or more aliases, creates
+copies named for the aliases."""
+
+
+import argparse
+import collections
+import logging
+import os
+from os import path
+import shutil
+import subprocess
+
+import add_aliases
+
+from nototools import tool_utils
+from nototools import unicode_data
+
+logger = logging.getLogger('emoji_thumbnails')
+
+def create_thumbnail(src_path, dst_path):
+  # uses imagemagik
+  # we need imagex exactly 72x72 in size, with transparent background
+  subprocess.check_call([
+      'convert', '-thumbnail', '72x72', '-gravity', 'center', '-background',
+      'none', '-extent', '72x72', src_path, dst_path])
+
+
+def get_inv_aliases():
+  """Return a mapping from target to list of sources for all alias
+  targets in either the default alias table or the unknown_flag alias
+  table."""
+
+  inv_aliases = collections.defaultdict(list)
+
+  standard_aliases = add_aliases.read_default_emoji_aliases()
+  for k, v in standard_aliases.iteritems():
+    inv_aliases[v].append(k)
+
+  unknown_flag_aliases = add_aliases.read_emoji_aliases(
+      'unknown_flag_aliases.txt')
+  for k, v in unknown_flag_aliases.iteritems():
+    inv_aliases[v].append(k)
+
+  return inv_aliases
+
+
+def filename_to_sequence(filename, prefix, suffix):
+  if not filename.startswith(prefix) and filename.endswith(suffix):
+    raise ValueError('bad prefix or suffix: "%s"' % filename)
+  seq_str = filename[len(prefix): -len(suffix)]
+  seq = unicode_data.string_to_seq(seq_str)
+  if not unicode_data.is_cp_seq(seq):
+    raise ValueError('sequence includes non-codepoint: "%s"' % filename)
+  return seq
+
+
+def sequence_to_filename(seq, prefix, suffix):
+  return ''.join((prefix, unicode_data.seq_to_string(seq), suffix))
+
+
+def create_thumbnails_and_aliases(src_dir, dst_dir, dst_prefix):
+  """Creates thumbnails in dst_dir based on sources in src.dir, using
+  dst_prefix. Assumes the source prefix is 'emoji_u' and the common suffix
+  is '.png'."""
+
+  if not path.isdir(src_dir):
+    raise ValueError('"%s" is not a directory')
+  dst_dir = tool_utils.ensure_dir_exists(dst_dir)
+
+  src_prefix = 'emoji_u'
+  suffix = '.png'
+
+  inv_aliases = get_inv_aliases()
+
+  for src_file in os.listdir(src_dir):
+    try:
+      seq = unicode_data.strip_emoji_vs(
+          filename_to_sequence(src_file, src_prefix, suffix))
+    except ValueError as ve:
+      logger.warning('Error (%s), skipping' % ve)
+      continue
+
+    src_path = path.join(src_dir, src_file)
+
+    dst_file = sequence_to_filename(seq, dst_prefix, suffix)
+    dst_path = path.join(dst_dir, dst_file)
+
+    create_thumbnail(src_path, dst_path)
+    logger.info('wrote thumbnail: %s' % dst_file)
+
+    for alias_seq in inv_aliases.get(seq, ()):
+      alias_file = sequence_to_filename(alias_seq, dst_prefix, suffix)
+      alias_path = path.join(dst_dir, alias_file)
+      shutil.copy2(dst_path, alias_path)
+      logger.info('wrote alias: %s' % alias_file)
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument(
+      '-s', '--src_dir', help='source images', metavar='dir', required=True)
+  parser.add_argument(
+      '-d', '--dst_dir', help='destination directory', metavar='dir',
+      required=True)
+  parser.add_argument(
+      '-p', '--prefix', help='prefix for thumbnail', metavar='str',
+      default='android_')
+  parser.add_argument(
+      '-v', '--verbose', help='write log output', metavar='level',
+      choices='warning info debug'.split(), const='info',
+      nargs='?')
+  args = parser.parse_args()
+
+  if args.verbose is not None:
+    logging.basicConfig(level=getattr(logging, args.verbose.upper()))
+
+  create_thumbnails_and_aliases(
+      args.src_dir, args.dst_dir, args.prefix)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/unknown_flag_aliases.txt b/unknown_flag_aliases.txt
new file mode 100644
index 000000000..3708463ab
--- /dev/null
+++ b/unknown_flag_aliases.txt
@@ -0,0 +1,25 @@
+# alias table
+# from;to
+# the 'from' sequence should be represented by the image for the 'to' sequence
+# these are flags we explicitly omit
+
+# flag aliases
+1f1e7_1f1f1;fe82b # BL
+1f1e7_1f1f6;fe82b # BQ
+1f1e9_1f1ec;fe82b # DG
+1f1ea_1f1e6;fe82b # EA
+1f1ea_1f1ed;fe82b # EH
+1f1eb_1f1f0;fe82b # FK
+1f1ec_1f1eb;fe82b # GF
+1f1ec_1f1f5;fe82b # GP
+1f1ec_1f1f8;fe82b # GS
+1f1f2_1f1eb;fe82b # MF
+1f1f2_1f1f6;fe82b # MQ
+1f1f3_1f1e8;fe82b # NC
+1f1f5_1f1f2;fe82b # PM
+1f1f7_1f1ea;fe82b # RE
+1f1f9_1f1eb;fe82b # TF
+1f1fc_1f1eb;fe82b # WF
+1f1fd_1f1f0;fe82b # XK
+1f1fe_1f1f9;fe82b # YT
+