Product
Introducing Rust Support in Socket
Socket now supports Rust and Cargo, offering package search for all users and experimental SBOM generation for enterprise projects.
By Trevor Norris - Jul 31, 2025
You're Invited:Meet the Socket Team at BlackHat and DEF CON in Las Vegas, Aug 4-6.RSVP →
reading-position-indicator
Advanced tools
reading position indicator
Small mobile friendly reading position indicator library with no external dependencies.
demo
- https://codepen.io/kunukn/full/zNJqEE (version 1.0.3+)
- https://codepen.io/kunukn/full/ayeMZN/ (version 2.0.0+)
about
A position indicator at the top of the page to visually display how far you have scrolled on a webpage.
Build with focus on simplicity, performance and a11y. Using transform translate for best performance. rAF for throttling scroll update and debounce for resize update.
Aria tags are used to support screen readers.
The progress element <progress> has not been used because the code gets messy with vendor prefixes and removing the default styles that comes with each browser. It gets even messier when fallback elements are added inside the progress element to support older browsers.
browser support
 |  |  |  |  |
|---|---|---|---|---|
| IE 10+ ✔ | Latest ✔ | Latest ✔ | Latest ✔ | Latest ✔ |
npm
https://www.npmjs.com/package/reading-position-indicator
size
- js
~6kb - css
<1kb
test
Tested with latest Chrome, Safari, Firefox, Edge, IE10+, iOS7+, Android 4.3+
usage
Check the dist/index.html for inspiration.
- Add reference to
rpi.bundle.jsandrpi.bundle.cssin the html page - Apply the markup structure
- Init the library with JS
html structure
<head>
...
<link rel="stylesheet" href="rpi.bundle.css">
...
</head>
<body>
<!-- library markup -->
<div class="rpi-progress-bar"
role="progressbar"
aria-valuemin="0"
aria-valuemax="100"
aria-valuenow="0">
<div class="rpi-progress-bar__position" aria-hidden="true"></div>
<div class="rpi-progress-bar__percentage"></div>
</div>
<!-- end library markup -->
...
<script src="rpi.bundle.js"></script> <!-- library -->
<script>new ReadingPositionIndicator().init();</script> <!-- usage -->
</body>
minimum markup required
<div class="rpi-progress-bar">
<div class="rpi-progress-bar__position"></div>
<div class="rpi-progress-bar__percentage"></div>
</div>
configuration and usage example
var rpi;
setTimeout(function waitUntilDomIsReadyLoadingCustomFontsMightOffsetThis() {
rpi = new ReadingPositionIndicator({
rpiArea: '[data-rpi-area]', /* optional, query selector to an element */
progressBar: { /* optional */
show: true, /* default true */
color: 'rgba(0, 120, 120, .5)', /* default from css */
},
percentage: { /* optional */
show: true, /* default false */
displayBeforeScroll: false, /* default false */
opacity: .3, /* default from css */
color: '#000', /* default from css */
},
}).init();
}, 200); // wait until DOM has fully rendered the article to get the calculations correct
// rpi.destroy(); // use when to be removed
// rpi.update(); // optional force update, example: DOM was updated and need to refresh the indicator
development
- git clone the project or download it
- npm install
- npm start
- open a browser and go to localhost:3333
build library into dist folder
- npm run build
how does it work?
It calculate heights for viewport, document and current scroll position. If rpiArea is used then it also uses getBoundingClientRect method to calculate dom element dimension. DOM updates are only applied if data has changed since last time. The calculation is updated on scroll and resize event and the information is updated to the DOM.
license
MIT License: http://opensource.org/licenses/MIT
2.0.3
- Ensure displayed percentage does not exceed 100%
Keywords
FAQs
Reading position indicator on a webpage
The npm package reading-position-indicator receives a total of 46 weekly downloads. As such, reading-position-indicator popularity was classified as not popular.
We found that reading-position-indicator demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
Package last updated on 13 Aug 2018
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Related posts
Product
Announcing Precomputed Reachability Analysis in Socket
Socket’s precomputed reachability slashes false positives by flagging up to 80% of vulnerabilities as irrelevant, with no setup and instant results.
By Martin Torp - Jul 30, 2025
Product
Socket Now Protects the Chrome Extension Ecosystem
Socket is launching experimental protection for Chrome extensions, scanning for malware and risky permissions to prevent silent supply chain attacks.
By Mix Irving, Alexandros Kapravelos, Eli Insua - Jul 30, 2025