String template functions

These template functions help you format, transform, and shape text. Use them to build friendly messages, clean up sensor values, or prepare text for dashboards and notifications.

Home Assistant extends the Jinja2 template engine with many custom functions, filters, and tests. Each function on this page has its own page with detailed descriptions, parameters, and practical examples.

New to templates? Start with the templating documentation to learn the basics.

• Capitalize first character capitalize Capitalizes the first character of a string and lowercases the rest.
• Center text in a field center Centers a string in a field of a given width, padding with spaces.
• Escape HTML characters escape Escapes HTML special characters in a string so they display as literal text.
• Format byte size as human-readable filesizeformat Formats a byte count as a human-readable file size string like 1.2 MB.
• Force-escape HTML characters forceescape Escapes HTML special characters, even on strings already marked as safe.
• Printf-style string ting format Formats a string using printf-style placeholders like %s, %d, and %f.
• Indent text indent Indents text by a given number of spaces, with options for the first line and blank lines.
• Join a list into a string join Joins a list of values into a single string with a separator between each element.
• Convert to case lower Converts all characters in a string to lowercase.
• Convert number to ordinal Converts a number to its ordinal string representation (1st, 2nd, 3rd, and so on).
• Pretty-print a value pprint Pretty-prints a value in a readable format, useful for debugging templates.
• Replace occurrences in a string replace Replaces all occurrences of a substring with another string.
• Mark as HTML safe Marks a string as safe HTML so it will not be escaped when rendered.
• Convert to slug format slugify Converts a string to a slug format with an optional separator character.
• Strip HTML tags striptags Removes all HTML/XML tags from a string, leaving only the text content.
• Convert to case title Converts a string to title case, capitalizing the first letter of each word.
• Strip whitespace trim Strips leading and trailing whitespace (or specified characters) from a string.
• Truncate text to a length truncate Truncates a string to a given length, appending an ellipsis if it was shortened.
• Convert to case upper Converts all characters in a string to uppercase.
• URL-encode a value urlencode URL-encodes a dictionary of values for use in HTTP requests.
• Convert URLs to HTML links urlize Converts plain text URLs into HTML links.
• Count words in text wordcount Counts the number of words in a string.
• Wrap text at a line width wordwrap Wraps text at a given line width by inserting line breaks.
• Convert dictionary to HTML attributes xmlattr Converts a dictionary into an XML/HTML attribute string.