PROPOSED Web Fonts Working Group Charter

The mission of the Web Fonts Working Group is to develop specifications that allow the interoperable deployment of downloadable fonts on the Web.

Join the Web Fonts Working Group.

This proposed charter is available on GitHub. Feel free to raise issues.

Charter Status See the group status page and detailed change history.
Start date [dd monthname yyyy] (date of the "Call for Participation", when the charter is approved)
End date [dd monthname yyyy] (Start date + 2 years)
Chairs Vladimir Levantovsky (W3C Invited Experts)
Garret Rieger (Google)
Team Contacts Chris Lilley (0.16 FTE)
Meeting Schedule Teleconferences: 1-hour calls will be held weekly or as needed
Face-to-face: we will meet during the W3C's annual Technical Plenary week; additional face-to-face meetings may be scheduled by consent of the participants, usually no more than 3 per year.


The problem

WOFF 1.0 and 2.0 are widely implemented W3C Recommendations. However, for fonts with many glyphs (such as are typically used for Chinese and Japanese, for example), even with the compression provided by WOFF 1 or 2, download sizes are still too large. Static subsetting runs the risk of malformed rendering of complex scripts, missing glyphs, or some text being rendered in a fallback font. Dynamic subsetting can mean poor use of CDNs or intermediate caches.


Early API experiments by Adobe and Monotype demonstrated the feasibility of a font enrichment API, where a server delivers a font with minimal glyph repertoire and the client can query the full repertoire and request additional subsets on-the-fly. The API takes care of progressively enriching the downloaded font, without requiring cumbersome CSS manipulations or multiple, separate font files. This API could be implemented as a script library, or as a native browser API.

In other experiments, the Brotli compression used in WOFF 2 was extended to support shared dictionaries and patch update. This avoids the need for a new API or a new transport protocol. It still requires the browser to implement dynamic patching and refresh of in-use font resources.

Some, but not all, solutions break layout features across text segments; this is undesirable.

The Web Fonts WG is developing a technology, Incremental Font Transfer, which allows a web page to download a small subsetted font to display that page, and then to incrementally request updates to that font as more pages are visited. Two variants are under investigation; one gives very high performance but requires an intelligent font server, the other is less performant but can be deployed to any standard HTTP server.


The Web Fonts WG will develop Recommendation-track specifications for Incremental Font Transfer as listed under deliverables; track emerging implementations, and maintain communications with the typography, Web design and implementor communities.

Out of Scope

The following features are out of scope, and will not be addressed by this Working group.

  • Changes to the Open Font Format or OpenType specifications


Updated document status is available on the group publication status page.

Draft state indicates the state of the deliverable at the time of the charter approval. Expected completion indicates when the deliverable is projected to become a Recommendation, or otherwise reach a stable state.

Normative Specifications

The Working Group will deliver the following W3C normative specifications:

In addition, Working Group maintains the following W3C normative specifications:

Non-normative Specifications

Other Deliverables

Other non-normative documents may be created such as:

  • Use case and requirement documents;
  • Test suite and implementation report for the specification;
  • Primer or Best Practice documents to support web developers when designing applications.


  • Mar 2023: Updated WD of Incremental Font Transfer
  • Mar 2024: CR Snapshot of Incremental Font Transfer

Success Criteria

In order to advance to Proposed Recommendation, each normative specification is expected to have at least two independent, interoperable implementations of every feature defined in the specification, where interoperability can be verified by passing open test suites, and two or more implementations interoperating with each other. In order to advance to Proposed Recommendation, each normative specification must have an open test suite of every feature defined in the specification.

There should be testing plans for each specification, starting from the earliest drafts.

To promote interoperability, all changes made to specifications in Candidate Recommendation or to features that have deployed implementations should have tests. Testing efforts should be conducted via the Web Platform Tests project.

Each specification should contain sections detailing all known security and privacy implications for implementers, Web authors, and end users.

Each specification should contain a section on accessibility that describes the benefits and impacts, including ways specification features can be used to address them, and recommendations for maximising accessibility in implementations.


For all specifications, this Working Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG. Invitation for review must be issued during each major standards-track document transition, including FPWD. The Working Group is encouraged to engage collaboratively with the horizontal review groups throughout development of each specification. The Working Group is advised to seek a review at least 3 months before first entering CR and is encouraged to proactively notify the horizontal review groups when major changes occur in a specification following a review.

Additional technical coordination with the following Groups will be made, per the W3C Process Document:

W3C Groups

CSS Working Group
The Cascading Style Sheets (CSS) Working Group maintains CSS Fonts, which defines the WebFont linking mechanism.

External Organizations

The Web Fonts WG will, if needed, coordinate with SC29/WG11 regarding the Open Font Format (OpenType) specification. Changes to Open Font Format (OpenType) are out of scope of the WebFonts WG, although requirements may be communicated to SC29/WG11 if needed via the existing Class C liaison between W3C and SC29.


To be successful, this Working Group is expected to have 6 or more active participants for its duration, including representatives from the key implementors of this specification, and active Editors and Test Leads for each specification. The Chairs, specification Editors, and Test Leads are expected to contribute half of a working day per week towards the Working Group. There is no minimum requirement for other Participants.

The group encourages questions, comments and issues on its public mailing lists and document repositories, as described in Communication.

The group also welcomes non-Members to contribute technical submissions for consideration upon their agreement to the terms of the W3C Patent Policy.

Participants in the group are required (by the W3C Process) to follow the W3C Code of Ethics and Professional Conduct.


Technical discussions for this Working Group are conducted in public: the meeting minutes from teleconference and face-to-face meetings will be archived for public review, and technical discussions and issue tracking will be conducted in a manner that can be both read and written to by the general public. Working Drafts and Editor's Drafts of specifications will be developed in public repositories and may permit direct public contribution requests. The meetings themselves are not open to public participation, however.

Information about the group (including details about deliverables, issues, actions, status, participants, and meetings) will be available from the Web Fonts Working Group home page.

Most Web Fonts Working Group teleconferences will focus on discussion of particular specifications, and will be conducted on an as-needed basis.

This group primarily conducts its technical work on GitHub issues. The public is invited to review, discuss and contribute to this work.

The group may use a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and members of the group, for member-only discussions in special cases when a participant requests such a discussion.

Decision Policy

This group will seek to make decisions through consensus and due process, per the W3C Process Document (section 5.2.1, Consensus). Typically, an editor or other participant makes an initial proposal, which is then refined in discussion with members of the group and other reviewers, and consensus emerges with little formal voting being required.

However, if a decision is necessary for timely progress and consensus is not achieved after careful consideration of the range of views presented, the Chairs may call for a group vote and record a decision along with any objections.

To afford asynchronous decisions and organizational deliberation, any resolution (including publication decisions) taken in a face-to-face meeting or teleconference will be considered provisional. A call for consensus (CfC) will be issued for all resolutions (for example, via email, GitHub issue or web-based survey), with a response period from one week to 10 working days, depending on the chair's evaluation of the group consensus on the issue. If no objections are raised by the end of the response period, the resolution will be considered to have consensus as a resolution of the Working Group.

All decisions made by the group should be considered resolved unless and until new information becomes available or unless reopened at the discretion of the Chairs or the Director.

This charter is written in accordance with the W3C Process Document (Section 5.2.3, Deciding by Vote) and includes no voting procedures beyond what the Process Document requires.

Patent Policy

This Working Group operates under the W3C Patent Policy (Version of 15 September 2020). To promote the widest adoption of Web standards, W3C seeks to issue Web specifications that can be implemented, according to this policy, on a Royalty-Free basis. For more information about disclosure obligations for this group, please see the licensing information.


This Working Group will use the W3C Software and Document license for all its deliverables.

About this Charter

This charter has been created according to section 3.4 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Charter History

The following table lists details of all changes from the initial charter, per the W3C Process Document (section 4.3, Advisory Committee Review of a Charter):

Charter Period Start Date End Date Changes
Initial Charter, WOFF 1.0 17 Mar 2010 31 March 2012 none
Charter Extension 29 May 2012 30 Sep 2012 none
Rechartered 24 Oct 2012 31 May 2015

Investigation of improved font compression schemes for WOFF, and a new Recommendation-track deliverable, WOFF 2.0

Charter Extension 8 Apr 2015 31 May 2017 none
Charter Extension 10 Jul 2017 31 Aug 2017 none
Charter Extension 11 Jan 2018 30 Apr 2018 none
Rechartered 13 Dec 2018 13 Sept 2022 Investigation of progressive font enrichment options, and a new Recommendation-track deliverable for the chosen solution. 2020-11-10: Garret Rieger (Google) appointed as group co-chair.
Rechartered 15 December 2020 13 September 2022 New Patent Policy. 2021-01-28: Vladimir Levantovsky (W3C Invited Experts) re-appointed as group co-chair
This charter Update to latest charter template.

Change log

Changes to this document are documented in this section.