Functions vs Filters Quick Reference

Filters: Transform Values

Syntax:{{ value | filter }}or{{ value |> filter }}

Use when: You have a value to transform

Examples:

{{ text | upper }}
{{ pages |> where('draft', false) |> sort_by('date') }}
{{ page.content | markdown | safe }}

Functions: Standalone Operations

Syntax:{{ function() }}or{{ function(arg) }}

Use when: Performing an operation or lookup

Examples:

{{ get_page('docs/about') }}
{{ get_data('data/authors.json') }}
{{ ref('docs/getting-started') }}
{{ page_exists('path') }}

Decision Tree

Do I have a value to transform?
├─ Yes → Use filter (| or |>)
│   └─ Example: {{ text | upper }}
│
└─ No → Use function (direct call)
    └─ Example: {{ get_page('path') }}

Common Patterns

Filter a collection:

{{ site.pages |> where('type', 'blog') |> sort_by('date') }}

Get data, then filter:

{% let authors = get_data('data/authors.json') %}
{% let active = authors |> where('active', true) %}

Function result in filter chain:

{% let section = get_section('blog') %}
{{ section.pages |> limit(5) }}

Quick Examples