Why Kuikly’s New Web Edition Beats Flutter and Others in Size and Speed

1. Background

Kuikly is Tencent’s widely used cross‑end development framework built on Kotlin Multiplatform, offering a unified tech stack for developers. It is launched by Tencent’s Oteam and is already used by over 20 businesses, with more than 1,000 pages and over 500 million daily active users, meeting diverse complex requirements. Kuikly, as a key member of the Tencent End‑Service Alliance, will continue to drive cross‑end technology innovation and ecosystem construction.

The framework now expands from Android, iOS and HarmonyOS to also support Web (H5) and WeChat Mini‑Program, further extending multi‑device adaptation scenarios. Kuikly’s H5 and Mini‑Program have been integrated into several Tencent services such as Sogou Input, Goose Market, and QQ Mini‑Games.

2. Effect Demonstration

Kuikly Web version has realized most core component capabilities on H5 and WeChat Mini‑Program, with the following running effect:

3. Comparison with Mainstream Solutions

Kuikly is designed on a client‑side technology stack, supporting high‑performance cross‑end on Android, iOS, and HarmonyOS, and now also H5 and Mini‑Program, similar to other cross‑end frameworks such as Flutter and Compose Multiplatform.

We selected two frameworks and compared them with Kuikly in H5 and Mini‑Program scenarios across several dimensions.

1 Product Size

On the H5 platform, the compiled bundle size of the three frameworks varies greatly, with Kuikly showing a clear advantage.

Industry cross‑end solutions based on client tech stacks use a self‑draw engine and run via WASM in browsers, resulting in large bundle sizes.

Kuikly Web uses a DOM rendering approach without third‑party dependencies, producing a much smaller bundle of only 463 KB.

2 Page Load Speed

Performance tests (Hello World demo) on iOS, Android and PC browsers show Kuikly loads fastest in all three environments.

2.1 iOS Load Speed Comparison

2.2 Android Load Speed Comparison

2.3 PC Performance Data

On a MacBook Pro M4Pro using Chrome 138.0.7204.158, Kuikly’s First Contentful Paint (FCP) is only 87.76 ms, less than half of the other frameworks.

3 Other Advantages

Compared with mainstream cross‑end frameworks on H5, Kuikly also offers:

Development experience: comprehensive support in Android Studio.

Code debugging: direct JS debugging or Kotlin debugging via SourceMap.

SEO friendliness: DOM rendering enables traditional SEO optimizations.

Compatibility: relies only on ES6 and CSS3, supported by most devices.

Ecosystem reuse: compiled JS can integrate with React and other H5 libraries.

4 WeChat Mini‑Program Support

While most client‑tech‑stack cross‑end frameworks lack official WeChat Mini‑Program runtime support, Kuikly Web’s Mini‑Program fills this gap.

4. Overall Technical Solution

1 Kuikly Architecture Review

The core layer handles framework logic, while the Render layer manages platform‑specific rendering. New platforms need to implement their own Render layer.

2 Kuikly Web Version Overall Design

During H5 and Mini‑Program adaptation, many code parts were shared, leading to the abstraction of a Web container runtime as an adaptation layer, which depends on abstracted DOM API, KuiklyWindow, and KuiklyDocument to implement most rendering logic.

2.1 Web Container Runtime

The runtime provides:

Conversion of Kuikly UI operations to standard DOM operations.

Extension interfaces for specialized modules such as animation, list, and text measurement.

Support for JS hosts to implement the runtime interface and integrate Kuikly.

2.2 H5 Runtime

Browsers already provide standard DOM, Window, and Document; Kuikly only needs to implement a few extension interfaces for animation, scrolling lists, and text measurement.

2.3 WeChat Mini‑Program Runtime

Existing cross‑end frameworks for Mini‑Program are mainly front‑end based, using compile‑time or runtime data‑driven templates. We drew inspiration from Tarojs and Kbone, implementing a lightweight DOM and extension interfaces tailored to Kuikly’s needs, with optimizations for its rendering flow.

Future work includes compiling Kuikly output to WASM and using pre‑compilation to improve Mini‑Program performance.

5. Technical Outlook

Continue performance optimization of Kuikly Web, using pre‑compilation to further improve Mini‑Program performance and reduce bundle size.

Explore WASM to accelerate compute‑intensive tasks and enhance user experience.

Expand Kuikly Web support to include an open‑source Electron adaptation later this year.

🚀 Experience Kuikly now and join the open‑source community.