diff --git a/tool/format-release b/tool/format-release
index a4331bb317..a84fd913ee 100755
--- a/tool/format-release
+++ b/tool/format-release
@@ -1,6 +1,8 @@
 #!/usr/bin/env ruby
 # https://rubygems.org/gems/diffy
 require "diffy"
+require "open-uri"
+require "yaml"
 
 Diffy::Diff.default_options.merge!(
   include_diff_info: true,
@@ -10,24 +12,22 @@ Diffy::Diff.default_options.merge!(
 class Tarball
   attr_reader :version, :sha256
 
-  def initialize(path, size, sha1, sha256, sha512)
-    /\A\/(?:[^\/\n]*\/)*(?:ruby-(?<ver>(?<xy>\d+\.\d+)\.\d+(?:-(?:preview|rc)\d+)?)[0-9a-z.\-]+)/ =~ path \
-      or raise "tarball path doesn't mach regexp"
-    @path = path
+  def initialize(version, url, size, sha1, sha256, sha512)
+    @url = url
     @size = size
     @sha1 = sha1
     @sha256 = sha256
     @sha512 = sha512
-    @version = ver
-    @xy = xy
+    @version = version
+    @xy = version[/\A\d+\.\d+/]
   end
 
-  def gz?;  @path.end_with?('.gz'); end
-  def zip?; @path.end_with?('.zip'); end
-  def bz2?; @path.end_with?('.bz2'); end
-  def xz?;  @path.end_with?('.xz'); end
+  def gz?;  @url.end_with?('.gz'); end
+  def zip?; @url.end_with?('.zip'); end
+  def bz2?; @url.end_with?('.bz2'); end
+  def xz?;  @url.end_with?('.xz'); end
 
-  def ext; @path[/(?:zip|tar\.(?:gz|bz2|xz))\z/]; end
+  def ext; @url[/(?:zip|tar\.(?:gz|bz2|xz))\z/]; end
 
   def to_md
     <<eom
@@ -45,31 +45,69 @@ eom
   #   SHA1:   21f62c369661a2ab1b521fd2fa8191a4273e12a1
   #   SHA256: 97cea8aa63dfa250ba6902b658a7aa066daf817b22f82b7ee28f44aec7c2e394
   #   SHA512: 1e2042324821bb4e110af7067f52891606dcfc71e640c194ab1c117f0b941550e0b3ac36ad3511214ac80c536b9e5cfaf8789eec74cf56971a832ea8fc4e6d94
-  def self.parse(wwwdir, file)
+  def self.parse(wwwdir, version)
     ary = []
-    ver = nil
-    File.read(file).scan(/^\* .*(?:\n .*)*/) do |unit|
-      path, size, sha1, sha256, sha512 = unit.lines.map(&:chomp)
-      path.slice!(0, 2)
-      size = size[/\d+/].to_i
-      sha1 = sha1[/\h{40}/]
-      sha256 = sha256[/\h{64}/]
-      sha512 = sha512[/\h{128}/]
-      tarball = Tarball.new(path, size, sha1, sha256, sha512)
-      if ver
-        raise "mixed versions" if tarball.version != ver
-      else
-        ver = tarball.version
-      end
+
+    unless /\A(\d+)\.(\d+)\.(\d+)(?:-(?:preview|rc)\d+)?\z/ =~ version
+      raise "unexpected version string '#{version}'"
+    end
+    x = $1.to_i
+    y = $2.to_i
+    z = $3.to_i
+    # previous tag for git diff --shortstat
+    # It's only for x.y.0 release
+    if z != 0
+      prev_tag = nil
+    elsif y != 0
+      prev_tag = "v#{x}_#{y-1}_0"
+      prev_ver = "#{x}.#{y-1}.0"
+    elsif x == 3 && y == 0 && z == 0
+      prev_tag = "v2_7_0"
+      prev_ver = "2.7.0"
+    else
+      raise "unexpected version for prev_ver '#{version}'"
+    end
+
+    uri = "https://cache.ruby-lang.org/pub/tmp/ruby-info-#{version}-draft.yml"
+    info = YAML.load(URI(uri).read)
+    if info.size != 1
+      raise "unexpected info.yml '#{uri}'"
+    end
+    info[0]["size"].each_key do |ext|
+      url = info[0]["url"][ext]
+      size = info[0]["size"][ext]
+      sha1 = info[0]["sha1"][ext]
+      sha256 = info[0]["sha256"][ext]
+      sha512 = info[0]["sha512"][ext]
+      tarball = Tarball.new(version, url, size, sha1, sha256, sha512)
       ary << tarball
     end
-    xy = ver[/\A\d+\.\d+/]
+
+    if prev_tag
+      # show diff shortstat
+      tag = "v#{version.gsub(/[.\-]/, '_')}"
+      stat = `git diff --shortstat #{prev_tag}..#{tag}`
+      changes, add, delete = stat.scan(/\d+/)
+      puts stat
+      puts <<eom
+See [NEWS](https://github.com/ruby/ruby/blob/#{tag}/NEWS) or [commit logs](https://github.com/ruby/ruby/compare/#{prev_tag}...#{tag}) for more details.
+
+With those changes, [stat](https://github.com/ruby/ruby/compare/#{prev_tag}...#{tag}) since Ruby #{prev_ver}!
+
+その他詳細については、[NEWS](https://github.com/ruby/ruby/blob/#{tag}/NEWS) ファイルまたは[コミットログ](https://github.com/ruby/ruby/compare/#{prev_tag}...#{tag})を参照してください。
+
+なお、こうした変更により、Ruby #{prev_ver} 以降では [#{changes} 個のファイルに変更が加えられ、#{add} 行の追加と #{delete} 行の削除が行われました](https://github.com/ruby/ruby/compare/#{prev_tag}...#{tag}) !
+eom
+    end
+
+    xy = version[/\A\d+\.\d+/]
+    puts "## Download\n\n"
     ary.each do |tarball|
       puts tarball.to_md
     end
-    update_branches_yml(ver, xy, wwwdir)
-    update_downloads_yml(ver, xy, wwwdir)
-    update_releases_yml(ver, xy, ary, wwwdir)
+    update_branches_yml(version, xy, wwwdir)
+    update_downloads_yml(version, xy, wwwdir)
+    update_releases_yml(version, xy, ary, wwwdir)
     ary
   end
 
@@ -191,7 +229,9 @@ def main
     STDERR.puts "usage: format-release <dir-of-w.r-l.o> <output-of-make-snapshot>"
     exit
   end
-  Tarball.parse(ARGV[0], ARGV[1])
+  wwwdir = ARGV.shift
+  version = ARGV.shift
+  Tarball.parse(wwwdir, version)
 end
 
 main