ModularJS
Compile-time
No Proxy, no Virtual DOM. The compiler emits surgical DOM updates — it knows exactly which node depends on which value.
ModularJS
The compile-time front-end framework.
No Proxy, no Virtual DOM.
Reactivity is resolved at compile time. Components are native Web Components with their own Shadow DOM. Deep reactivity by default, and SSR included.
0.99× Svelte 5 ~24 KB brotli (~27 gzip) Native Web Components SSR included
Fast & light
0.99× Svelte 5 on the official benchmark, ~24 KB brotli (~27 KB gzip), and ~15 ms for 1M deep mutations. No runtime Proxy overhead.
Standard
Each component is a Custom Element with its own Shadow DOM. No proprietary runtime — just the platform.
Real, interactive code
This counter is a live MJS component. Reactivity is compiled — clicking updates only the number, nothing else.
<script> $count = 0 inc = -> $count++ </script> <button @click={inc}> Clicks : {$count} </button>
Live result
Measured performance
0.99×
Svelte 5 (joint run, js-framework-benchmark keyed, 07/20/26)
1.02×
Solid (joint run, js-framework-benchmark keyed, 07/20/26)
~24 KB
runtime, brotli
~15 ms
1M deep mutations
Everything you need
Deep reactivity
Nested objects and arrays track automatically.
SSR
Render-then-replace, Declarative Shadow DOM.
Transitions & animations
Built-in transitions and FLIP animations.
Router
A client-side router, batteries included.
Stores & context
Global state with $$ stores and § context.
Dynamic components
<@module> mounts a component by name.
Snippets & slots
Reusable markup fragments and named slots.
Error boundaries
<@failed> catches errors and shows a fallback.
How it compares
| Criterion | MJS | Svelte | React | Solid |
|---|---|---|---|---|
| Approach | compile-time | compile-time | VDOM | compile-time |
| Runtime | ~24 KB | ~10 KB | ~45 KB | ~7 KB |
| Deep reactivity, no Proxy | ✓ | partial | no | manual |
| Native Web Components | ✓ | no | no | no |
| SSR | ✓ | ✓ | ✓ | ✓ |
Figures are indicative and meant to be honest, not promotional.
Go further
Ready to build?
One command to get the framework.
npm install mjs-framework