Tyler Tork

Like blog posts, a Page can have an “Excerpt” field to override the automatic excerpt of 55 words from the beginning of the content. However, many themes don’t display this field when editing pages, so you can’t edit it.
This extremely simple plugin forces page excerpt capability “on”. The Page excerpt is visible in internal search results and “Query Loop” blocks, as well as in the output of many plugins (e.g. CC Child Pages). So I generally do want to decide for myself whether to accept the default excerpt.

Torknado Page Excerpt

Pages, like Posts, can have an Excerpt field to override the automatic "first 55 words" excerpt. However, many themes don't enable edit …

Husain Ahmed

This plugin remove extra p and br tags from the_content, the_excerpt and widget_text_content.

Empty P Tag

This plugin is very easy to install and use, there are no extra setting to do.

Easy and best performance

This plugin hides empty paragraphs and make your butyfull design without breaking design.

Torknado Page Excerpt vs Empty P Tag