Collabora ports YouTube's Chromium-based Chrobalt engine to RDK TV platforms

How YouTube runs on TVs today

Open YouTube on a smart TV and check Settings → App Version: a string like 25.lts signals classic Cobalt, the lightweight open-source HTML5, CSS and JavaScript engine Google built for resource-constrained living room hardware. According to a Collabora blog post by Santosh Mahto that reached the Hacker News front page, that engine talks to the underlying platform through an abstraction layer called Starboard, which is how OEMs and SoC vendors have historically ported YouTube to custom silicon. Full browser engines such as Chromium were simply not viable on low-power set-top boxes and TVs given tight RAM and CPU budgets.

From Cobalt to Chrobalt

Collabora explains that keeping an independent layout and rendering engine in step with the rapidly evolving web ecosystem is a huge undertaking, so Google began merging Cobalt's code with Chromium to obtain a robust, standards-compliant rendering pipeline. The result is Chrobalt, which started with release 26.eap and now sits at 27.lts, tracking modern Chromium milestones such as 138 and above. In Collabora's description, Chrobalt is a Chromium embedder with a Starboard porting layer, combining upstream web features and rapid security updates with low-footprint media pipelines tailored to TV and set-top box hardware.

Google already maintains reference ports for desktop and Android, but Collabora notes the story was incomplete without a reference port aimed at external device manufacturers.

Building the RDK reference platform

Over more than a year, Collabora says it worked directly with Google's YouTube Cobalt and partner engineering teams to port, integrate and stabilize Chrobalt on an RDK (Reference Design Kit) platform for Amlogic chipsets, producing what it calls the first RDK-based Chrobalt reference platform for third-party devices — a foundational design for Google device partners such as Samsung and LG.

The integration and validation work spanned several areas:

• Decoupling and restructuring legacy Starboard recipes across the RDK Yocto layers, and modernizing toolchains to support the newer C++ standards Chromium requires.
• Integrating Chromium's unit test suites alongside Starboard's NPLB (No Platform Left Behind) conformance suite to establish baseline platform compatibility.
• Configuring the platform to pass the YouTube Test Suite (YTS) requirements, covering 4K/UHD playback, DRM handling and low-latency input.
• Integrating Chrobalt into RDK's modular plugin architecture, including RDK7 support, with lifecycle management, memory sandboxing and a unified audio/video pipeline.
• Upstreaming critical fixes to the Cobalt and Starboard codebases for the broader ecosystem.

Driving certification over DAB

YTS runs are driven over the Device Automation Bus (DAB). Collabora says it co-authored the Rust reference implementation of DAB, known as dab-adapter, contributed to the DAB Compliance Test Suite, and extended and fixed the adapter on the Starboard platform so the device could be driven reliably and reproducibly through a full YTS run.

The company also reports that at the YouTube Device Partner Summit in Japan in April, the Chrobalt RDK reference platform was presented to industry partners as a validated, production-ready path for next-generation living room deployments, and that the work received acknowledgment in Google's BlinkOn-21 lightning talks.

Why it matters

The port demonstrates that a Chromium-class engine is now a realistic option on constrained TV hardware rather than a non-starter, which is a meaningful shift for how the living room web gets built. For manufacturers on RDK — particularly those using Amlogic silicon — a validated reference design plus upstreamed Starboard and DAB code substantially lowers the barrier to adopting the new engine, while the Starboard layer preserves a path to custom SoCs.

For viewers, a broader Chrobalt rollout should mean YouTube on TVs keeps pace with modern web standards and Chromium security fixes instead of depending on a purpose-built engine that lags the wider web. Collabora's closing suggestion: switch on your smart TV, check Settings → App Version, and look for 27.lts or later.