HbbTV Developer Portal
Search ⌘K
Developer Guide API Reference News & Insight Deployments Showcase

HbbTV 2.0.5 explained

HbbTV 2.0.5 is an incremental but significant update to HbbTV 2.0.4, marking the next step in the evolution of HbbTV. Published in March 2026, version 2.0.5 formalises capabilities that many devices already support, strengthens interoperability, and introduces new foundations for secure and advanced interactive services.

While this is not a complete architectural overhaul, it represents an important technical consolidation. The biggest change is the formal integration of DRM into the core specification, alongside WebAssembly support and strengthened web security requirements.

In addition, HbbTV 2.0.5 improves DVB-I integration, introduces support for new video codecs and HTTP/3 as optional features, and includes numerous corrections and simplifications.

Summary of key changes

HbbTV 2.0.5 introduces:

Three mandatory new features:

  • DRM (Digital Rights Management)
  • WebAssembly
  • Additional web security specifications (HSTS, CSP2, upgrade-insecure-requests)

Optional new features:

  • New video codecs (AV1 and VVC)
  • HTTP/3
  • New DVB-I application models (from DVB A177r7)

Other changes:

  • 75 errata corrections to HbbTV 2.0.4
  • Removals, simplifications and deprecations
  • Clarifications and improvements to DVB-I integration (Annex O)

DRM is now formally integrated

Perhaps the most important change in 2.0.5 is the formal integration of DRM into the core specification.

In practice, HbbTV devices have supported DRM for many years, most commonly Microsoft PlayReady and in some cases Google Widevine. However, DRM was not previously defined in the core HbbTV specification due to market sensitivities.

HbbTV 2.0.5 now:

  • Makes support for at least one of the DRM systems listed in the HbbTV DRM specification mandatory (PlayReady or Widevine).
  • Harmonises how DRM is implemented across devices.
  • Enables conformance testing for DRM as part of the HbbTV device test suite.
  • Provides a clear baseline for secure premium content delivery.

Importantly, HbbTV already provides an open-source DASH and DRM reference application and associated test content. HbbTV members can:

  • Access anonymised results from running the reference application across more than 100 TV models.
  • Re-use code from the reference implementation in their own developments.

This practical tooling significantly lowers integration barriers and improves interoperability across the ecosystem.

By formalising DRM in the core specification and integrating it into conformance testing, HbbTV 2.0.5 ensures a consistent, interoperable and future-proof approach to secure content delivery. This is essential for broadcasters, platform operators and rights holders delivering premium services while maintaining a seamless experience for viewers.

In October 2025 the HbbTV Association ran a webinar on DRM, covering the standards, market insight and information from real-world deployments.

WebAssembly (WASM) support

WebAssembly is now formally included in the specification.

Many HbbTV devices already include WebAssembly support through browser engines such as Chrome or WebKit, but this was not explicitly required before. HbbTV 2.0.5 makes WebAssembly part of the baseline platform.

WebAssembly enables:

  • Near-native execution performance within HbbTV applications.
  • Advanced functionality such as software decoding of auxiliary video streams.
  • Faster deployment of new features without requiring firmware updates from device manufacturers.

A notable example demonstrated by 3Cat at IBC 2025 and the HbbTV Symposium 2025 used WebAssembly to decode sign-language video streams efficiently.

By formalising WebAssembly, HbbTV enables innovation at application level, accelerating time-to-market for advanced features across the installed base.

In March 2025 the HbbTV Association ran a webinar on WASM, which looked forward to 2.0.5 and included background details on WASM, details on what was going to be included in 2.0.5 and a review of the use cases.

Enhanced web security requirements

HbbTV 2.0.5 strengthens web security by mandating additional specifications that were previously optional or inconsistently implemented.

New mandatory security features include:

  • HSTS (HTTP Strict Transport Security)
    Ensures HTTPS/TLS is used for secure communication.
  • CSP2 (Content Security Policy Level 2)
    Controls which resources a page can load and protects against cross-site scripting and other attacks.
  • upgrade-insecure-requests
    Automatically replaces HTTP URLs with HTTPS where possible.

Most implementations already supported these measures, but 2.0.5 ensures consistent baseline security across devices. This is particularly important as hybrid TV services become more sophisticated and increasingly integrated with online platforms.

New video codecs and a separate codec registry

HbbTV 2.0.5 introduces a separate “Registry of Video Codecs”.

This registry lists:

  • Supported codecs and HDR technologies, and where they are specified
  • How applications can test for codec support availability

The registry allows for new codecs to be added without changing the core HbbTV specification.

Support for AV1 and VVC is defined as optional in 2.0.5.

By separating codec evolution from the core specification, HbbTV creates a more flexible model that allows adaptation to future industry developments while maintaining stability in the core standard.

HTTP/3 support

HTTP/3 which is based on QUIC, has been added as an optional feature.

In earlier deployments, inconsistencies in HTTP/2 support across browsers, ISPs and servers led to unexpected service disruptions. By explicitly defining HTTP/3 in the specification and enabling test coverage, HbbTV reduces the risk of similar issues in future.

Making HTTP/3 part of the testable feature set improves robustness and predictability for application developers and service providers.

Improved DVB-I integration

HbbTV 2.0.4 introduced Annex O, defining integration with DVB-I. Version 2.0.5 builds on this with clarifications and corrections.

Notably:

  • Approximately 30 of the 75 errata relate to Annex O.
  • The 4 new DVB-I application models from DVB A177r7 are supported.
  • Applications can now be associated with entire service lists (types 4.1/4.2/4.3).
  • This enables platforms or service aggregators to obtain, renew GDPR consent, manage terms and conditions, and support single sign-on.
  • It enables applications to support users withdrawing consent.
  • Applications can also run in series with media presentation (type 1.3), for example to enable proactive DRM licence acquisition.

These changes strengthen the alignment between HbbTV and DVB-I and reflect practical implementation feedback from early deployments.

Removals and simplifications

HbbTV 2.0.5 also streamlines the specification by removing or simplifying features that are obsolete or rarely used:

  • Removal of Tiresias and specific font definitions.
  • Partial removal of MediaSync functionality that was complex and not used in practice. Synchronising video over broadcast and audio of broadband is complex to implement and no longer relevant, as it is now practical for both video and audio to be sent via broadband.
  • Removal of “Do Not Track”, this was specified for the wider web but was not widely adopted.
  • Making “Transport Stream over IP” optional (it contained support is primarily for backward compatibility with the oldest HbbTV device).

These changes reduce implementation complexity and improve interoperability.

Memory management and MSE

Managed Media Sources, an approved requirement concerning improved memory management for Media Source Extensions (MSE) has not been adopted outside of the Apple ecosystem and therefore is not included in the 2.0.5 specification.

The specification acknowledges that devices may evict buffered data when memory is low and notify applications via a bufferedchange event, potentially offering a better user experience than terminating applications.

75 errata corrections

HbbTV 2.0.5 includes 75 errata accumulated over approximately 18 months. Most came from HbbTV 2.0.4 but some were inherited from earlier versions.

Some corrections relate to accessibility features introduced in 2.0.4, while others address clarifications and technical refinements, particularly around DVB-I integration.

This consolidation significantly improves specification clarity and implementation stability.

Conclusion

HbbTV 2.0.5 is an incremental update, but an important one.

Its three mandatory new features: DRM, WebAssembly and enhanced web security. This formalises capabilities already present in many devices and create a harmonised, interoperable baseline.

Optional additions such as AV1, VVC and HTTP/3 prepare the ecosystem for next-generation services, while improvements to DVB-I integration reflect real-world implementation feedback.

Together, these changes demonstrate HbbTV’s continued evolution as a stable, open and future-ready platform for hybrid broadcast and broadband television.