select2 is larger (approximately 30KB minified) but provides a rich set of features, including AJAX support and theming. The trade-off in size is justified for applications that need its advanced capabilities, but it may affect performance in very large datasets.

choices.js is a lightweight library (around 10KB minified) that offers fast performance with minimal impact on load times. Its small size makes it ideal for projects where bandwidth and loading speed are concerns.

tom-select is designed to be lightweight (around 10KB minified) while providing modern features like tagging and multi-select. Its focus on performance makes it a great choice for applications that need a fast, responsive dropdown without the bloat.

selectize has a moderate size (about 15KB minified) and offers good performance with tagging and drag-and-drop features. It strikes a balance between functionality and load time, making it suitable for most web applications without significant performance hits.

select2 provides robust customization capabilities, including theming, custom templates for options and selections, and extensive configuration options. It is highly flexible, allowing developers to create unique designs and functionalities as needed.

choices.js offers extensive customization options, including the ability to style elements using CSS, customize templates, and configure behavior through a simple API. It allows for deep customization while maintaining a clean and intuitive interface.

tom-select is highly customizable, with support for custom templates, styles, and a flexible API. It encourages developers to create their own styles and functionalities, making it easy to integrate into various design systems while maintaining accessibility.

selectize allows for significant customization, particularly in styling and templating. It supports custom rendering of options and tags, and its API is designed to be straightforward, making it easy to implement custom features while keeping the default behavior intact.

select2 also supports tagging, and it does so with a robust implementation that includes AJAX loading of tags, making it suitable for large datasets. Its tagging feature is highly configurable, allowing for seamless integration with existing data sources.

choices.js supports tagging out of the box, allowing users to create new options dynamically. This feature is particularly useful for multi-select scenarios where users may need to add items that are not predefined in the list.

tom-select includes tagging functionality, enabling users to add new options as they type. It is designed to be fast and responsive, with a clean interface that makes tagging easy and efficient, especially in multi-select contexts.

selectize was one of the pioneers in tagging support for select boxes. It allows users to create new tags on the fly, and it handles them elegantly within the dropdown. The tagging feature is intuitive and works well with both single and multi-select scenarios.

select2 has made significant improvements in accessibility, including better keyboard navigation and support for screen readers. However, it is essential to implement it correctly and test with assistive technologies to ensure a fully accessible experience.

choices.js is built with accessibility in mind, providing keyboard navigation and screen reader support. It follows ARIA standards to ensure that all interactive elements are usable by people with disabilities, making it a good choice for inclusive design.

tom-select prioritizes accessibility, offering features like keyboard navigation, ARIA attributes, and support for screen readers. It is designed to be usable by all individuals, including those with disabilities, making it a reliable choice for accessible web applications.

selectize aims to be accessible, but it requires some additional work to ensure full compliance with accessibility standards. Developers are encouraged to enhance its accessibility features, particularly for keyboard navigation and screen reader support.

select2 is also user-friendly, especially for those familiar with jQuery. Here’s a basic example:

<select id="select2-example" style="width: 200px;">
  <option value="">Select a fruit</option>
  <option value="apple">Apple</option>
  <option value="banana">Banana</option>
  <option value="cherry">Cherry</option>
</select>

<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.13/css/select2.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.13/js/select2.min.js"></script>
<script>
  $(document).ready(function() {
    $('#select2-example').select2();
  });
</script>

choices.js is easy to integrate and use, with a straightforward API and good documentation. Here’s a simple example:

<select id="choices-example" class="choices" multiple>
  <option value="apple">Apple</option>
  <option value="banana">Banana</option>
  <option value="cherry">Cherry</option>
</select>

<script src="https://cdn.jsdelivr.net/npm/choices.js/public/assets/scripts/choices.min.js"></script>
<script>
  const choices = new Choices(document.getElementById('choices-example'), {
    removeItemButton: true,
    searchEnabled: true,
  });
</script>

tom-select is designed to be intuitive and easy to use. Here’s a simple implementation:

<select id="tom-select-example" placeholder="Select a fruit" multiple>
  <option value="apple">Apple</option>
  <option value="banana">Banana</option>
  <option value="cherry">Cherry</option>
</select>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/tom-select/dist/css/tom-select.css" />
<script src="https://cdn.jsdelivr.net/npm/tom-select/dist/js/tom-select.complete.min.js"></script>
<script>
  new TomSelect('#tom-select-example', {
    plugins: ['remove_button'],
    create: true,
  });
</script>

selectize is straightforward to use, with clear documentation. Here’s a quick example:

<select id="selectize-example" placeholder="Select or type..."></select>

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/selectize.js/0.12.6/css/selectize.default.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/selectize.js/0.12.6/js/standalone/selectize.min.js"></script>
<script>
  $('#selectize-example').selectize({
    plugins: ['remove_button'],
    create: true,
  });
</script>