Breadcrumbs for GitHub Pages / Jekyll. Pure Liquid (no Jekyll plugin). https://seanh.github.io/posts/2020/01/01/jekyll-breadcrumbs/

README.md

Jekyll Breadcrumbs

This is a Jekyll template include that renders navigation breadcrumbs for a page or post. The breadcrumbs include the page or post's collection, categories, date and title. They look something like this:

Home > Posts > 2019 > Dec > 23 > My Blog Post

Installation

Copy both the breadcrumbs.html and breadcrumb_text.html files below into your Jekyll site's _includes/ folder.

Usage

To render the breadcrumbs for the current page:

{% include breadcrumbs.html %}

To render the breadcrumbs for another page:

{% include breadcrumbs.html page=another_page %}

To render breadcrumbs with the home page and date omitted (see Options below for more options):

{% include breadcrumbs.html omit_home=true omit_date=true %}

Options

omit_home : Don't include the home page as the first breadcrumb.

omit_collection : Don't include the page's collection ("posts" by default, for posts) in the breadcrumbs.

omit_categories : Don't include the page's categories in the breadcrumbs.

omit_date : Don't include the post's date (year, month and day) in the breadcrumbs.

omit_year : Don't include the post's year in the breadcrumbs.

omit_month : Don't include the post's month in the breadcrumbs.

omit_date : Don't include the post's date in the breadcrumbs.

breadcrumb_text.html

{% assign breadcrumb_page = nil %}
{% for page in site.pages %}
  {% if page.url == include.url %}
    {% assign breadcrumb_page = page %}
    {% break %}
  {% endif %}
{% endfor %}

{% assign breadcrumb_text = breadcrumb_page.breadcrumb_text | default: breadcrumb_page.title | default: include.default %}

{% unless breadcrumb_page == nil %}
  <a href="{{ breadcrumb_page.url | relative_url }}">{{ breadcrumb_text }}</a>
{% else %}
  {{ breadcrumb_text }}
{% endunless %}
>

breadcrumbs.html

{% assign omit_home = include.omit_home %}
{% if omit_home == nil %}
  {% assign omit_home = site.breadcrumbs_omit_home %}
{% endif %}

{% assign omit_collection = include.omit_collection %}
{% if omit_collection == nil %}
  {% assign omit_collection = site.breadcrumbs_omit_collection %}
{% endif %}

{% assign omit_categories = include.omit_categories %}
{% if omit_categories == nil %}
  {% assign omit_categories = site.breadcrumbs_omit_categories %}
{% endif %}

{% assign omit_date = include.omit_date %}
{% if omit_date == nil %}
  {% assign omit_date = site.breadcrumbs_omit_date %}
{% endif %}

{% assign omit_year = include.omit_year %}
{% if omit_year == nil %}
  {% assign omit_year = site.breadcrumbs_omit_year %}
{% endif %}

{% assign omit_month = include.omit_month %}
{% if omit_month == nil %}
  {% assign omit_month = site.breadcrumbs_omit_month %}
{% endif %}

{% assign omit_day = include.omit_day %}
{% if omit_day == nil %}
  {% assign omit_day = site.breadcrumbs_omit_day %}
{% endif %}

{% assign breadcrumbs = "" | split: "" %}

{% if page.url == "/" %}
  {% assign is_front_page = true %}
{% else %}
  {% assign is_front_page = false %}
{% endif %}

{% unless is_front_page %}
  {% assign page = include.page | default: page %}
  {% unless omit_home %}
    {% capture breadcrumb_text %}{% include breadcrumb_text.html url="/" default="Home" %}{% endcapture %}
    {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
    {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
  {% endunless %}
{% endunless %}

{% unless omit_collection or page.collection == nil %}
  {% assign collection_slug = page.collection | replace: " ", "-" | downcase | url_encode %}
  {% assign collection_page_url = "/" | append: collection_slug | append: "/" %}
  {% capture breadcrumb_text %}{% include breadcrumb_text.html url=collection_page_url default=page.collection %}{% endcapture %}
  {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
  {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
{% endunless %}

{% unless omit_categories %}
  {% for category in page.categories %}
    {% assign category_slug = category | replace: " ", "-" | downcase | url_encode %}
    {% assign category_page_url = "/" | append: category_slug | append: "/" %}
    {% capture breadcrumb_text %}{% include breadcrumb_text.html url=category_page_url default=category %}{% endcapture %}
    {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
    {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
  {% endfor %}
{% endunless %}

{% unless omit_date or page.date == nil %}
  {% assign year = page.date | date: "%Y" %}
  {% assign year_page_url = "/" | append: year | append: "/" %}
  {% assign month_int = page.date | date: "%m" %}
  {% assign month_page_url = year_page_url | append: month_int | append: "/" %}
  {% assign day_int = page.date | date: "%d" %}
  {% assign day_page_url = month_page_url | append: day_int | append: "/" %}

  {% unless omit_year %}
    {% capture breadcrumb_text %}{% include breadcrumb_text.html url=year_page_url default=year %}{% endcapture %}
    {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
    {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
  {% endunless %}

  {% unless omit_month %}
    {% assign month_str = page.date | date: "%b" %}
    {% capture breadcrumb_text %}{% include breadcrumb_text.html url=month_page_url default=month_str %}{% endcapture %}
    {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
    {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
  {% endunless %}

  {% unless omit_day %}
    {% assign day_str = page.date | date: "%e" %}
    {% capture breadcrumb_text %}{% include breadcrumb_text.html url=day_page_url default=day_str %}{% endcapture %}
    {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
    {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
  {% endunless %}
{% endunless %}

{% unless is_front_page %}
  {% if page.title == nil %}
    {% assign title = page.name %}
  {% else %}
    {% assign title = page.title %}
  {% endif %}
  {% capture breadcrumb_text %}<strong>{{ title }}</strong>{% endcapture %}
  {% assign breadcrumb_text = breadcrumb_text | split: "🗾" %}
  {% assign breadcrumbs = breadcrumbs | concat: breadcrumb_text %}
{% endunless %}

{% if breadcrumbs != empty %}
  <nav style="display: inline-block;">
    {% for breadcrumb in breadcrumbs %}{{ breadcrumb }}{% endfor %}
  </nav>
{% endif %}