Filters

Filters transform data in expressions. Apply them with the pipe (|) operator.

{{ post.title|upper }}
{{ post.excerpt|truncate(100) }}
{{ post.content|striptags|excerpt(25) }}

String

Filter	Example	Description
upper	post.title|upper	Convert to uppercase
lower	post.title|lower	Convert to lowercase
capitalize	post.title|capitalize	Capitalize first letter
title	post.title|title	Convert to title case
trim	post.title|trim	Remove whitespace or characters
truncate	post.excerpt|truncate(100)	Limit string length
excerpt	post.content|excerpt(25)	Trim to word count
excerpt_chars	post.content|excerpt_chars(200)	Trim to character count
striptags	post.content|striptags	Remove HTML tags
nl2br	post.content|nl2br	Newlines to <br>
spaceless	html|spaceless	Remove whitespace between tags
pretags	post.content|pretags	Escape HTML inside <pre>
replace	post.title|replace('old', 'new')	Replace text
split	'a,b,c'|split(',')	Split into array
slug	post.title|slug	URL-friendly slug
sanitize	post.title|sanitize	Alias for slug
format	'%s has %d posts'|format(user.name, count)	sprintf-style formatting
url_encode	query|url_encode	URL encode
relative	post.link|relative	Absolute URL to relative

Number

Filter	Example	Description
number_format	1234.5|number_format(2)	Format with decimals and separators
number_i18n	1234|number_i18n	Format using WordPress localization
abs	-5|abs	Absolute value
round	4.567|round(1)	Round number

Date

Filter	Example	Description
date	post.date|date('F j, Y')	Format date
date_i18n	post.timestamp|date_i18n('F j, Y')	Format with WordPress localization
date_modify	post.date|date_modify('+1 day')	Modify date
time_ago	post.date|time_ago	Human-readable time difference

Array

Filter	Example	Description
first	posts|first	First element
last	posts|last	Last element
join	names|join(', ')	Join into string
list	names|list	Human-readable list (A, B and C)
length	posts|length	Count elements
keys	data|keys	Get keys
values	data|values	Get values
slice	posts|slice(0, 3)	Extract portion
batch	items|batch(3)	Group into batches
column	users|column('name')	Extract column
merge	categories|merge(tags)	Merge arrays
reverse	posts|reverse	Reverse order
shuffle	posts|shuffle	Randomize order
sort	items|sort	Sort
filter	posts|filter(p => p.featured)	Keep matching elements
map	posts|map(p => p.title)	Transform each element
reduce	items|reduce((a, b) => a + b, 0)	Reduce to single value
find	posts|find(p => p.featured)	Find first match
array	value|array	Ensure value is array
wp_list_filter	posts|wp_list_filter({status: 'publish'})	Filter using wp_list_filter()

WordPress

Filter	Example	Description
wpautop	post.content|wpautop	Add paragraph tags
wptexturize	post.title|wptexturize	Smart quotes and dashes
shortcodes	post.content|shortcodes	Process shortcodes
stripshortcodes	post.content|stripshortcodes	Remove shortcodes
antispambot	user.user_email|antispambot	Obfuscate email
kses_post	post.meta('html_field')|kses_post	Output HTML (overrides default escaping)

Utility

Filter	Example	Description
default	post.subtitle|default('No subtitle')	Fallback if empty
json_encode	data|json_encode	Encode as JSON

Intl

Requires the PHP intl extension.

Filter	Example	Description
country_name	'US'|country_name	Country name from code
currency_name	'USD'|currency_name	Currency name from code
currency_symbol	'EUR'|currency_symbol	Currency symbol from code
language_name	'fr'|language_name	Language name from code
locale_name	'en_US'|locale_name	Locale name from code
timezone_name	'Europe/Paris'|timezone_name	Timezone name from identifier
format_currency	price|format_currency('USD')	Format as currency
format_number	0.75|format_number('percent')	Format number
format_date	post.date|format_date('long')	Localized date
format_time	post.date|format_time('short')	Localized time
format_datetime	post.date|format_datetime	Localized date and time

WooCommerce

Requires WooCommerce.

Filter	Example	Description
currency	product.price|currency	Format as store currency via wc_price()