はてなブログ文字数カウンター is a free Chrome add-on developed by NAO. It is designed to count the number of characters in the title and body of a blog post while editing on Hatena Blog.

When editing a blog post on Hatena Blog, this add-on counts the characters in the title and body in real-time, providing a convenient way to keep track of the character count.

During the counting process, all whitespace characters, line breaks, specific HTML tags, and Hatena notation strings are excluded, ensuring accurate character count for your blog posts.

With はてなブログ文字数カウンター, bloggers can easily monitor and manage the length of their titles and body content, helping them optimize their blog posts for readability and SEO purposes.