Overlays suck, but if you need one, consider using Parvus. Parvus is an open source, dependency free image lightbox with the goal of being accessible.

Installation

Download

CSS:
- dist/css/parvus.min.css (minified) or
- dist/css/parvus.css (un-minified)
JavaScript:
- dist/js/parvus.min.js (minified) or
- dist/js/parvus.js (un-minified)

Link the .css and .js files in your HTML:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Page title</title>
  <!-- CSS -->
  <link href="path/to/parvus.min.css" rel="stylesheet">
</head>
<body>
  <!-- HTML content -->
  <!-- JS -->
  <script src="path/to/parvus.min.js"></script>
</body>
</html>

Package Managers

You can also install Parvus using npm or yarn:

npm install parvus

yarn add parvus

After installation, import Parvus into your JavaScript codebase:

import Parvus from 'parvus'

Be sure to include the corresponding SCSS or CSS file.

Usage

Link a thumbnail image with the class lightbox to a larger image:

<a href="path/to/image.jpg" class="lightbox">
  <img src="path/to/thumbnail.jpg" alt="">
</a>

Initialize the script:

const prvs = new Parvus()

Captions

There are three ways to add a caption to an image:

Reference by ID

You can add an ID to your caption element and reference it from the trigger element using the data-caption-id attribute.

<figure>
  <a href="path/to/image.jpg" class="lightbox" data-caption-id="caption-1">
    <img src="path/to/thumbnail.jpg" alt="">
  </a>
  <figcaption id="caption-1">
    I'm a caption, and I live outside the link.
  </figcaption>
</figure>

Direct Attribute

You can add a data-caption attribute directly to the trigger element.

<a href="path/to/image.jpg" class="lightbox" data-caption="I'm a simple caption">
  <img src="path/to/thumbnail.jpg" alt="">
</a>

Child Element

Alternatively, set the option captionsSelector to select a caption from a child element's innerHTML.

<a href="path/to/image.jpg" class="lightbox">
  <figure class="figure">
    <img src="path/to/thumbnail.jpg" alt="">
    <figcaption class="figure__caption">
      I'm a caption inside a child element
    </figcaption>
  </figure>
</a>

const prvs = new Parvus({
  captionsSelector: '.figure__caption',
})

Copyright

There are three ways to add copyright information to an image:

Reference by ID

You can add an ID to your copyright element and reference it from the trigger element using the data-copyright-id attribute.

<a href="path/to/image.jpg" class="lightbox" data-copyright-id="copyright-1">
  <img src="path/to/thumbnail.jpg" alt="">
</a>
<small id="copyright-1" hidden>
  © 2026 Photographer Name
</small>

Direct Attribute

You can add a data-copyright attribute directly to the trigger element.

<a href="path/to/image.jpg" class="lightbox" data-copyright="© 2026 Photographer Name">
  <img src="path/to/thumbnail.jpg" alt="">
</a>

Child Element

Alternatively, set the option copyrightSelector to select a copyright from a child element's innerHTML.

<a href="path/to/image.jpg" class="lightbox">
  <figure class="figure">
    <img src="path/to/thumbnail.jpg" alt="">
    <small class="figure__copyright">
      © 2026 Photographer Name
    </small>
  </figure>
</a>

const prvs = new Parvus({
  copyrightSelector: '.figure__copyright',
})

Gallery

To group related images into a set, add a data-group attribute:

<a href="path/to/image.jpg" class="lightbox" data-group="Berlin">
  <img src="path/to/thumbnail.jpg" alt="">
</a>
<a href="path/to/image_2.jpg" class="lightbox" data-group="Berlin">
  <img src="path/to/thumbnail_2.jpg" alt="">
</a>
//...
<a href="path/to/image_8.jpg" class="lightbox" data-group="Kassel">
  <img src="path/to/thumbnail_8.jpg" alt="">
</a>

Alternatively, set the option gallerySelector to group all images with a specific class within a selector:

<div class="gallery">
  <a href="path/to/image.jpg" class="lightbox">
    <img src="path/to/thumbnail.jpg" alt="">
  </a>
  <a href="path/to/image_2.jpg" class="lightbox">
    <img src="path/to/thumbnail_2.jpg" alt="">
  </a>
  // ...
</div>

const prvs = new Parvus({
  gallerySelector: '.gallery',
})

Responsive Images

Specify different image sources and sizes using the data-srcset and data-sizes attributes:

<a href="path/to/image.jpg" class="lightbox"
data-srcset="path/to/small.jpg 700w,
             path/to/medium.jpg 1000w,
             path/to/large.jpg 1200w"
data-sizes="(max-width: 75em) 100vw,
            75em"
>
  <img src="path/to/thumbnail.jpg" alt="">
</a>

Localization

Import the language module and set it as an option for localization:

import de from 'parvus/src/l10n/de'
const prvs = new Parvus({
  l10n: de
})

Options

Customize Parvus by passing an options object when initializing:

const prvs = new Parvus({
  // Clicking outside does not close Parvus
  docClose: false
})

Available options include:

{
  // Selector for elements that trigger Parvus
  selector: '.lightbox',
  // Selector for a group of elements combined as a gallery, overrides the `data-group` attribute.
  gallerySelector: null,
  // Display zoom indicator
  zoomIndicator: true,
  // Display captions if available
  captions: true,
  // Selector for the element where the caption is displayed; use "self" for the `a` tag itself.
  captionsSelector: 'self',
  // Attribute to get the caption from
  captionsAttribute: 'data-caption',
  // Display copyright if available
  copyright: true,
  // Selector for the element where the copyright is displayed; use "self" for the `a` tag itself.
  copyrightSelector: 'self',
  // Attribute to get the copyright from
  copyrightAttribute: 'data-copyright',
  // Clicking outside closes Parvus
  docClose: true,
  // Close Parvus by swiping up/down
  swipeClose: true,
  // Accept mouse events like touch events (click and drag to change slides)
  simulateTouch: true,
  // Touch dragging threshold in pixels
  threshold: 100,
  // Hide browser scrollbar
  hideScrollbar: true,
  // Icons
  lightboxIndicatorIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M8 3H5a2 2 0 00-2 2v3m18 0V5a2 2 0 00-2-2h-3m0 18h3a2 2 0 002-2v-3M3 16v3a2 2 0 002 2h3"/></svg>',
  previousButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path stroke="none" d="M0 0h24v24H0z"/><polyline points="15 6 9 12 15 18" /></svg>',
  nextButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path stroke="none" d="M0 0h24v24H0z"/><polyline points="9 6 15 12 9 18" /></svg>',
  closeButtonIcon: '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M18 6L6 18M6 6l12 12"/></svg>',
  // Localization of strings
  l10n: en
}

API

Parvus provides the following API functions:

Function	Description
`open(element)`	Open the specified `element` (DOM element)
`close()`	Close Parvus
`previous()`	Show the previous image
`next()`	Show the next image
`select(index)`	Select a slide with the specified `index` (integer)
`add(element)`	Add the specified `element` (DOM element)
`remove(element)`	Remove the specified `element` (DOM element)
`destroy()`	Destroy Parvus
`isOpen()`	Check if Parvus is currently open
`currentIndex()`	Get the index of the currently displayed slide
`use(plugin, options)`	Register a plugin
`addHook(hookName, callback)`	Add a hook callback
`getPlugins()`	Get list of registered plugins

Events

Bind and unbind events using the .on() and .off() methods:

const prvs = new Parvus()
const listener = () => {
  console.log('eventName happened')
}
// Bind event listener
prvs.on(eventName, listener)
// Unbind event listener
prvs.off(eventName, listener)

Available events:

eventName	Description
`open`	Triggered after Parvus has opened
`select`	Triggered when a slide is selected
`close`	Triggered after Parvus has closed
`destroy`	Triggered after Parvus has destroyed

Plugins

Parvus supports a plugin system that allows you to extend its functionality.

Using Plugins

To use a plugin, call the .use() method after initialization:

import Parvus from 'parvus'
import MyPlugin from './my-plugin.js'
const prvs = new Parvus()
// Register plugin
prvs.use(MyPlugin, {
  // Plugin-specific options
  option1: 'value1',
  option2: 'value2'
})

Creating Plugins

A plugin is an object with a name and an install function:

const MyPlugin = {
  name: 'MyPlugin',
  install(parvus, options = {}) {
    // Plugin initialization code
    console.log('Plugin installed with options: ', options)
  }
}
export default MyPlugin

Plugin Hooks

Plugins can hook into various lifecycle events:

Hook Name	When Triggered	Provided Data
`afterInit`	After lightbox DOM is created (once)	`{ state }`
`afterOpen`	After lightbox opens	`{ element, state }`
`afterClose`	After lightbox closes	`{ state }`
`slideChange`	When slide changes	`{ index, oldIndex, state }`

Example using hooks:

const MyPlugin = {
  name: 'MyPlugin',
  install(parvus, options) {
    // Add a custom button on init
    parvus.addHook('afterInit', ({ state }) => {
      const btn = document.createElement('button')
      btn.classList.add('parvus__btn')
      btn.classList.add('parvus__btn--my-plugin')
      btn.textContent = 'Custom'
      btn.type = 'button'
      // Add to controls as first element
      if (state.controls) {
        state.controls.prepend(btn)
      }
    })
    // Track slide changes
    parvus.addHook('slideChange', ({ index, oldIndex }) => {
      console.log(`Changed from slide ${oldIndex} to ${index}`)
    })
  }
}

Browser Support

Parvus is supported on the latest versions of the following browsers:

Chrome
Edge
Firefox
Safari

Table of Contents

Installation

Download

Package Managers

Usage

Captions

Reference by ID

Direct Attribute

Child Element

Copyright

Reference by ID

Direct Attribute

Child Element

Gallery

Responsive Images

Localization

Options

API

Events

Plugins

Using Plugins

Creating Plugins

Plugin Hooks

Browser Support