How to fix "Parse error: syntax error, unexpected" in WordPress

A parse error means PHP, the language WordPress runs on, could not read a file. On the line the message names it met something that cannot come next in valid code, and it gave up there. PHP checks a whole file before it runs any of it, so when the file is the active theme's functions.php or part of an active plugin, every page stops, and the dashboard with them.

Nothing has been lost. Your posts, pages, settings and uploads are untouched, and the site returns as soon as the file is valid again. If you see "There has been a critical error on this website" in place of the "Parse error" line, the white screen of death page shows how to turn on the debug log, where the full line is written.

Read the message first

Parse error: syntax error, unexpected token "}", expecting ";" in /home/example/public_html/wp-content/themes/your-theme/functions.php on line 42

• The path names the file. A folder under wp-content/themes/ is a theme. A folder under wp-content/plugins/ is a plugin.
• The line number is where PHP gave up. That is at the mistake or after it, so check that line and the few above it.
• The word after "unexpected" is what PHP met when it was expecting something else.

Here is the code behind the message above. Line 41 has no semicolon, and PHP only notices at the brace on line 42.

function example_excerpt_length() {
	return 20
}
add_filter( 'excerpt_length', 'example_excerpt_length' );

Pasted code goes wrong in a handful of ways:

• A second opening tag. functions.php already begins with <?php. If the snippet does too, paste only what comes after it.
• A missing semicolon. PHP needs one at the end of each statement.
• A brace or quote left open, because only part of a snippet was copied.
• Curly quotes. PHP writes text between straight quotes, ' or ". The curly ones a web page or word processor puts in their place are not quotes to PHP. Retype them.
• Code pasted after a closing ?>. PHP ignores everything outside its tags, so this code does not run at all. Paste it above the ?>.

Keep it from happening again

• Put your own code in a child theme. Its functions.php holds only what you wrote, and an update to the parent theme does not remove it. See how to create a child theme.
• Try the change on a copy first. A staging site is a private copy of your site for this.
• Check the file before you upload it, with php -l as in the first fix.
• Know what the dashboard's own file editor does. When you save a PHP file there, WordPress loads the site to see whether it still works, and puts the old file back if it does not. A file uploaded over SFTP gets no such check.
• Use CSS for a change of appearance. It needs no PHP file. See how to add custom CSS.