KiCad now runs in-browser: What it means for PCB design workflows

The open-source PCB design landscape just got a major upgrade: KiCad, the widely adopted electronics design automation suite, is now accessible directly from a web browser. Developed by Emergence Engineering, a Hungarian software studio, this breakthrough eliminates the need for local software installation, enabling engineers to prototype and collaborate on circuit boards from nearly any device with a modern browser.

The project began as a side experiment by Viktor, the company’s CTO and a former electrical engineer, who aimed to replicate KiCad’s native OpenGL-based PCB canvas in a web environment. Early attempts relied on emulating the original code, resulting in buggy and inefficient performance. "I spent weeks hunting down weird emulation bugs before realizing a direct WebGL rewrite targeting KiCad’s Graphics Abstraction Layer was the only viable path," Viktor explained. The team’s persistence paid off: the first functional iteration loaded successfully and ran smoothly, validating their approach.

From hobby project to MVP: The technical journey behind the port

Emergence Engineering’s transition from a side project to a usable product wasn’t straightforward. The team leveraged an outdated wxWidgets web port as a foundation, gradually adapting it to KiCad’s requirements—a process still ongoing. "Bringing wxWidgets up to KiCad’s standards required rewriting large portions of the codebase," Viktor noted. "It’s been a marathon, not a sprint."

One of the most challenging hurdles involved porting multithreaded functionality to the web. KiCad’s Design Rule Check (DRC) and 3D renderer rely on pthreads, which Emscripten’s WebAssembly toolchain supports—but with significant caveats. "Asyncify, Pthreads, and native exceptions in Emscripten often conflict," Viktor said. "We had to rewrite parts of Binaryen, KiCad’s compiler toolchain, to suspend execution properly within catch blocks. This reduced the final bundle size by 30-40% and cut load times from 10 seconds to under one."

Optimizing bundle size became a critical focus. By splitting Open CASCADE, a 3D modeling library, into a separate lazy-loaded WebAssembly module, the team reduced the total payload from 180 MB to 130 MB (compressed to 24 MB with Brotli). "Further optimizations like -O2 or -Oz flags will require more finesse," Viktor added. "Every byte counts when you’re shipping a full PCB suite."

Collaboration and AI: The future of KiCad in the cloud

Emergence Engineering isn’t stopping at a browser-based KiCad. The team envisions a platform where engineers can collaborate in real time, integrate AI-driven design assistance, and share projects seamlessly—similar to how Red Hat commercialized Linux decades ago. "Our goal is to build a product layer on top of KiCad," Viktor explained. "Think enhanced collaboration, AI suggestions for component placement, and enterprise-grade features."

The company plans to offer a free tier for hobbyists and small teams, with a premium subscription around $30/month for larger or proprietary projects. Future plans include AI integrations, self-hosting options, and even native mobile versions. "We’re heads-down refining the first stable release, which we aim to launch within a month," Viktor said. "After that, we’ll focus on merging our changes back into KiCad’s core and wxWidgets."

All front-end code is released under the GPL license, aligning with KiCad’s open-source ethos. Emergence Engineering also plans to contribute back to the KiCad and wxWidgets communities, though Viktor admits this is uncharted territory for him. "I’ve released open-source projects before, but I’ve never contributed directly to a major codebase," he said. "We’re eager to collaborate and give back."

Compatibility and next steps for engineers

For now, the web-based KiCad works best on Firefox, with Chrome following closely and Safari in active development. Engineers can test it today with a demo project or upload their own designs. The source code is available on GitHub, and the team’s website offers updates on progress.

While still in its early stages—bugs remain and not all features are fully ported—the project signals a shift toward cloud-native PCB design. As web technologies like WebAssembly and WebGL mature, tools like this could redefine how engineers work, breaking down barriers between local and remote workflows. The next few months will be critical in determining whether this experiment evolves into a staple of the electronics design toolkit.