SolidJS is a modern, fine-grained reactive UI library that gives you a declarative component model with extremely low runtime overhead. Instead of using a Virtual DOM, Solid compiles JSX into highly optimized reactive primitives so updates touch only the exact DOM nodes that need to change. That design makes Solid feel like the best parts of React ergonomics, but with tighter control over reactivity and often measurable runtime gains.
The Use Case
When to use (pros)
- True fine-grained reactivity: State in Solid is tracked at the signal level, so reads/writes update only subscribers that actually depend on the value. This avoids broad re-renders and keeps runtime work minimal.
- No Virtual DOM, compiled outputs: Components get compiled to direct DOM-manipulating code and small reactive primitives, which reduces indirection and CPU work at runtime. That tends to show up as excellent real-world performance.
- Great TypeScript support and predictable semantics: Solid has first-class TypeScript typings and a predictable reactive model, which is pleasant for large codebases and refactors.
- Fullstack option with SolidStart: If you want a batteries-included experience for SSR, routing, adapters and deployments, SolidStart is the official meta-framework that fills that role. Use it when you want server rendering, streaming and routing patterns handled for you.
- Smallish runtime and focused mental model: The runtime is compact and the core API surface is intentionally small, so reasoning about performance is straightforward.
When not to use (cons)
- Different mental model from React: It looks like JSX and components, but the reactive primitives mean you need to think in terms of signals and dependencies. That has a short ramp for people used to React state and hooks.
- Smaller ecosystem than React: Compared to React, there are fewer third-party UI libraries and integration examples, so you might need to write more glue for niche tooling.
- Tooling and SSR edge cases: Solid does SSR well, but some advanced patterns or very specific integrations may require extra attention compared to more mature ecosystems. SolidStart helps, but there are still scenarios where you need to wire things carefully.
- Fewer engineers familiar with it: Hiring or onboarding teams that expect React semantics might take a bit longer, especially around reactive gotchas and fine-grained updates.
Suitability by Project Scale
Large companies
- Pros: Huge win when you need predictable, high-performance UIs at scale. For customer-facing surfaces where CPU and JS parse/execute time matter, Solid can reduce server and client costs and improve Time To Interactive.
- Cons: Ecosystem and tooling differences may lengthen integration time. If your stack relies heavily on React-first libraries or internal React conventions, porting and long-term support need planning.
Smaller projects
- Pros: Excellent for performance-sensitive dashboards, product landing pages, admin panels or any app where small runtime cost and snappy UI matter. Using SolidStart gives a clear path to SSR/SSG.
- Cons: If you value the broadest possible marketplace of ready-made components and tutorials, you will trade that for runtime benefits.
Personal / indie projects
- Pros: Great fit. You get modern reactivity and tiny runtime overhead without a ton of boilerplate. Fast prototype-to-production when you care about shipping less JS.
- Cons: If you expect to hand the project off to a team used only to React, there may be a learning step.