Platform/Roadmap2026

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Platform 2026 Roadmap

Warning: This is page is actively in-progress and is incomplete.

Related Links:

• Firefox Release Calendar (future)
• Firefox release notes for developers (past)
• Pocket Guide: Shipping Firefox

These are areas of work planned for Gecko in 2026 for the Web Platform.

For current web platform documentation of these areas, see the subsections at:

• https://developer.mozilla.org/en-US/docs/Web/

HTML

• popover=hint (1867743)\
• alpha & colorspace attributes in <input type=color&gt; elements (1919718)
• ...

CSS

• units: rcap, rch, rex, ric (1740584)
• <attr-type> values in attr() function (1986631, 1998245)
• color-mix() function multiple color arguments (2007772)
• shape() function on by default (1982941)
• :buffering, :muted, :paused, :playing, :seeking, :stalled, :volume-locked allow you to style <audio> <video> elements (1707584, 2014512)
• ::before and ::after on replaced elements (1931309)
• ::marker pseudo-element support counter-increment, counter-reset, counter-set, quotes properties (2000404)
• @container style() queries (2014404)
• CSS Anchor Positioning (1988225)
  • align-items, align-self, justify-items, justify-self, place-items, and place-self properties support anchor-center value (1909339)
  • position-anchor property supports value none (1999972)
• overflow, overflow-x, overflow-y properties supported on replaced elements (1999100)
• position-try-order (2008537)
• shape-outside property support xywh() and rect() functions (1983187)
• vertical-align as shorthand property for alignment-baseline, baseline-shift, and baseline-source properties (1830771)
• CSS properties and rendering of <fieldset> and <legend> (1935129)
  • margins, generated content, custom display values
• View transition types (2001878)
• ...

WebCompat:

• -webkit-perspective property (1362499)
• ...

CSSOM

• CSS Typed Object Model Level 1 (1278697)
• ...

SVG

• SVG URL media fragments (1999989)
• ...

Rendering

WebGPU:

• ...

Media

• JPEG XL Rust decoder prototype (1986393)

Media-related APIs like WebRTC

• HTMLMediaElement.captureStream() (2017708)
• WebRTC MediaStreamTrackProcessor (1749532)
• WebRTC VideoTrackGenerator (1749533)

DOM

• more characters for element and attribute names in methods (1773312)
  • Document.createAttribute(), Document.createAttributeNS(), Document.createElement(), Document.createElementNS()
  • Element.toggleAttribute(), Element.setAttribute(), Element.setAttributeNS()
  • DOMImplementation.createDocument()
  • customElements.define(), customElements.whenDefined()
• CloseWatcher interface (1966073)
• Document.execCommand() "paste" command in web content (1998195)
• HTMLSelectElement.showPicker() support list of options in <datalist> (1998668)_
• ...

JS

• CSS module scripts (1986681)
• islamic-umalqura calendar support in Intl (2011505)
• Iterator.concat() method (1986672)
• Iterator.zip() and Iterator.zipKeyed() static methods (2003333)
• ...

APIs

• CompressionStream and DecompressionStream support Brotli compression (1921583)
• Document.activeViewTransition property (2001836)
• Document Picture-in-Picture API (1858562)
• HTML Sanitizer API (1650370)
  • setHTML()
• Location.ancestorOrigins property (1085214)
• Navigation API (1997962)
  • NavigationPrecommitController.addHandler() (2009004)
• options.resizeQuality parameter support in Window.createImageBitmap() and WorkerGlobalScope.createImageBitmap() (2010125)
• pointerrawupdate event movementX and movementY properties (1987671)
• Reporting API (1976074, 2008916)
  • CSPViolationReport and IntegrityViolationReport objects using a ReportingObserver, can be filtered on type "csp-violation" or "integrity-violation"
• Trusted Types API (1994690)
• ...

Add-on gated:

• WebSerial API (926940)
• ...

Add-ons

• split view support (1993037)
• tabId parameter support in action.isEnabled and browserAction.isEnabled (2013477)
• ...

WebDriver

• browser.setDownloadBehavior command (1989022)
• browsingContext.getTree command now accepts the vendor specific moz:scope (1944568, 1944570)
• input.fileDialogOpened event (1855045)
• emulation.setScreenSettingsOverride command (2000651)
• script.realmCreated and script.realmDestroyed events (1936770)
• ...

Marionette:

• Reporting:GenerateTestReport command (1909662)
• implicit and pageLoad timeouts supported in line with script timeout; null values to disable the timeouts (2008345)
• ...

Protocols

HTTP

• ...

Security

• ...

Interop

Interop 2026 (2018559)

• Our announcement blog post: https://hacks.mozilla.org/2026/02/launching-interop-2026/

Interop Focus Areas for implementation:

• 2017321: CSS Anchor Positioning
• 2017328: CSS attr()
• 2017330: CSS contrast-color
• 2017331: Container style queries
• 2017332: Custom highlights
• 2017335: Dialogs and Popovers
• 2017337: Fetch
• 2017340: IndexedDB
• 2017341: JSPI for WASM
• 2017344: Navigation
• 2017353: Scoped custom element registries
• 2017354: Scroll-driven animations
• 2017355: scroll-snap
• 2017356: CSS shape
• 2017359: View transitions
• 2017360: zoom
• 2017361: Web compat
• 2017363: WebRTC
• 2017364: WebTransport

Prototyping

We have plans to prototype the following but no commitment (nor official "intent") to ship yet. Alphabetical, no indication of ordering of implementation or consideration for shipping.

• Fullscreen Keyboard Lock (700123)
• ...

Add-on gated:

• Web Bluetooth API (2022433)
• WebUSB API (2022432)
• ...

Specifications and Notes

Edit and publish new and updated specifications and notes. See Standards for our ongoing work in this area.

• ...

See Also

• Platform
• Previously: Platform/Roadmap2025
• Next: Platform/Roadmap2027