Life & fun · alternatives · 2026

This software runs JavaScript code during moments when the browser is idle, helping to improve website performance. It's designed for developers who want to optimize their sites by executing non-urgent tasks without… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Speed up your site by running JavaScript when the browser is idle launched in 2022; newer entries below may have overtaken it.

1. 1JL
   JS library to make your website instant▲426

   http://instantclick.io/ It seems the internet architecture won't bring us instant websites anytime soon. So here is a hack. I released this JS library last month (today is version 2.0 release, fixing v1.0's rough edges), it makes use of HTML5's pushState and preloading to make a website instant. It works like this: before clicking on a link, you'll hover over it. And there's a delay of 200-300 ms between these two events. InstantClick uses this delay to preload a page, when you click on a link it will display instantly in most case. (You can test on the website.) That's…

   2014 · its alternatives →

2. 2MY
   Make your site’s pages instant in one minute▲1,214

   Make your site’s pages instant in 1 minute and improve your conversion rate by 1%.

   2019 · instant.page · its alternatives →

3. 3
   Fast.js – faster reimplementations of native JavaScript functions▲323

   Faster user-land reimplementations for several common builtin native JavaScript functions. - codemix/fast.js

   2014 · github.com · its alternatives →

4. 4
   Instant Page▲416

   Make your site’s pages instant in 1 minute ⚡

   2019 · instant.page · its alternatives →

5. 5
   Faster.js – a micro-optimizing JavaScript compiler▲89

   faster.js is a Babel plugin that compiles idiomatic Javascript to faster, micro-optimized Javascript. - vzhou842/faster.js

   2018 · github.com · its alternatives →

6. 6
   A Firefox extension to add latency to distracting webpages▲232

   Download DelayWebpage for Firefox. Sets a small delay to certain websites to help you browse more mindfully.

   2020 · addons.mozilla.org · its alternatives →

7. 7
   UpUp▲306

   Make sure your sites work even when your users are offline

   2015 · talater.com · its alternatives →

8. 8VJ
   Velocity.js – Accelerated JavaScript animation▲160

   Velocity.js: An incredibly fast animation engine for motion designers.

   2014 · velocityjs.org · its alternatives →

9. 9
   Paper Programs – Run JavaScript on pieces of paper▲235

   Run Javascript programs on pieces of paper, using a projector and camera. Physically hold programs in your hand, and see them come to life, as if by magic.

   2018 · paperprograms.org · its alternatives →

10. 10MA
    Made a small JavaScript benchmarking app – BenchJS▲33

    Run, compare, and share JavaScript benchmarks in your browser with BenchJS.

    2024 · benchjs.com · its alternatives →

11. 11RU
    Run unsafe user generated JavaScript in the browser▲113

    I needed a way to let users write JavaScript to create plugins for a site I'm building. I couldn't find a solution I was happy with, so ended up building one that run's it in a web worker on a separate domain from your main site. Hopefully I haven't missed anything. If so, please let me know! My website has an interactive demo you can write code in the browser textarea, and see the output on the right. Interactive Demo: https://workerbox.net/ Github: https://github.com/markwylde/workerbox

    2022 · workerbox.net · its alternatives →

12. 12
    FasterChrome▲136

    Navigate the web faster by preloading pages on hovering

    2019 · chromewebstore.google.com · its alternatives →

13. 13
    QuickBEAM – run JavaScript as supervised Erlang/OTP processes▲113

    QuickBEAM is a JavaScript runtime embedded inside the Erlang/OTP VM. If you’re building a full-stack app, JavaScript tends to leak in anyway — frontend, SSR, or third-party code. QuickBEAM runs that JavaScript inside OTP supervision trees. Each runtime is a process with a `Beam` global that can: - call Elixir code - send/receive messages - spawn and monitor processes - inspect runtime/system state It also provides browser-style APIs backed by OTP/native primitives (fetch, WebSocket, Worker, BroadcastChannel, localStorage, native DOM, etc.). This makes it usable for: - SSR…

    Mar 2026 · github.com · its alternatives →

14. 14
    Execute JavaScript in a WebAssembly QuickJS sandbox▲206

    This TypeScript package allows you to safely execute JavaScript code within a WebAssembly sandbox using the QuickJS engine. Perfect for isolating and running untrusted code securely, it leverages the lightweight and fast QuickJS engine compiled to WebAssembly, providing a robust environment for code execution. Features - *Security*: Run untrusted JavaScript code in a safe, isolated environment. - *File System*: Can mount a virtual file system - *Custom Node Modules*: Custom node modules are mountable - *Fetch Client*: Can provide a fetch client to make http(s) calls - *Test-Runner*: Includes…

    2024 · github.com · its alternatives →

15. 15
    pagecheck▲67

    Convert more users by ensuring your site loads fast

    2020 · its alternatives →

16. 16
    An open source performance monitoring tool▲135

    Hey HN. We’re Jay and Vadim from Highlight.io (https://highlight.io). We’re building an open source [1] monitoring platform for web applications. Today we’re excited to be sharing a performance tool we’ve been working on, which helps you inspect the latency of code execution from the client to the server. As engineers at past startups, we often had to debug slow queries, poor load times, inconsistent errors, etc... While tools like Jaegar [2] helped us inspect server-side performance, we had no way to tie user events to the traces we were inspecting. In other words, although we had…

    2024 · github.com · its alternatives →

17. 17
    100+ Javascript Snippets for Beginners▲89

    Javascript snippets that can make your coding life easier

    2023 · 1amitarora.gumroad.com · its alternatives →

18. 18
    TrackJS JavaScript Error Monitoring▲119

    Discover the bugs in your web applications and fix them fast

    2014 · trackjs.com · its alternatives →

19. 19
    Browser JavaScript and Event Loop▲6

    Master how browser runs JavaScript under the hood.

    2020 · bonsaiilabs.com · its alternatives →

20. 20MY
    Make your app handle going offline▲151

    Offline.js is a Javascript and CSS library to automatically alert your users when they

    2013 · github.hubspot.com · its alternatives →

21. 21
    JavaScript Quiz▲190

    Check your JS knowledge by having fun.

    2021 · javascriptquiz.com · its alternatives →

22. 22
    Parallel DOM▲134

    Make your apps faster, parallelize away heavy DOM operations

    2024 · pdom.dev · its alternatives →

23. 23
    hasty.dev▲146

    A JS Perfomance Tool

    2021 · hasty.dev · its alternatives →

24. 24
    Motion on Firefox▲133

    Best time and attention manager, now available on Firefox

    2021 · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →