Handlebars.js review
A free, open-source template engine for JavaScript projects that need reusable HTML.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Handlebars.js is an open-source JavaScript templating language for developers generating HTML or other text from templates and input objects. It suits JavaScript projects that need reusable templates, with support for compiling templates into JavaScript functions and precompiling them. Its syntax is Mustache-compatible in many cases, which can help projects working with that template style. The project is distributed under the MIT license and is a library rather than a hosted commercial product.
Its main depth is in template composition and rendering. Built-in helpers handle conditional rendering, iteration and changing the evaluation context, while developers can register custom helpers for project-specific logic. Registered partials make it possible to reuse templates, including dynamic partials. Expressions are HTML-escaped by default, and the syntax also allows raw output when needed. Handlebars can generate other text formats as well as HTML, so the same basic model is not limited to web-page markup. These features make it a fit when developers want reusable rendering logic within JavaScript, rather than a broad visual authoring environment.
Handlebars is available as an open-source library, with web and self-hosted deployment options and documentation as its listed support channel. It is suitable across solo, small, mid-market and enterprise company sizes, though that fit does not make it a hosted service. The engine does not provide a built-in sandbox mode; guidance recommends isolating user-supplied templates in a separate sandbox. Teams rendering templates from untrusted users should plan for that isolation outside the engine. Choose Handlebars for JavaScript-based template composition and rendering; consider another approach if a managed hosted product or built-in sandboxing is central to the requirement.
Handlebars.js pros and cons
- Where it wins
- Compiles templates into JavaScript functions, with precompilation available
- Built-in helpers support conditions and iteration; custom helpers are supported
- Reuses registered partials and HTML-escapes expression output by default
- Where it doesn't
- Not a hosted commercial product; it is an open-source library
- User-supplied templates need a separate sandbox for isolation
- Support is documented through docs
Handlebars.js fact sheet, pricing and score →
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