If you want to display excerpts on index pages there are 2 ways to go about this. The easiest option in most cases is to use the built in ‘<!--more-->’ tag.

Inserting the more tag into posts tells WordPress where to stop the excerpt. This tag only works with ‘the_content’ and not ‘the_excerpt’.

The advantages of using the ‘<!--more-->’ tag are ease of use and being able to choose exactly where the excerpt stops in each post. The disadvantage is that it’s not an automatic function. When your WordPress theme uses the <?php the_content(); ?> tag you must use the ‘more’ tag or the entire post will be shown on those pages.

Automatic Excerpts

The default template tag to display excerpts by default is the ‘<?php the_excerpt(); ?>’ tag.

If you open one of your theme’s index files, such as index.php, archive.php or category.php, look for <?php the_content(); ?> and replace it with <?php the_excerpt(); ?>.

This template tag will cut off excerpts at 55 words and strip all html tags from the post content. This means that images or links (among other elements) will not display properly on pages other than the single post page.

Easy Custom Excerpts

Using The Excerpt Reloaded plugin you can easily set the excerpt length, the allowed html tags and much more. Very light theme editing is required, but well worth the effort! For more custom control of displaying excerpts take a look at ‘How to Customize WordPress Excerpts‘.