Service Workers Working Group Charter

The mission of the Service Workers Working Group is to enable Web applications to take advantage of persistent background processing, including hooks to enable bootstrapping of web applications while offline.

Join the Service Workers Working Group.

Charter Status See the group status page and detailed change history.
Start date 14 February 2023
End date 31 January 2025
Chairs Jake Archibald, Google
Team Contacts Yves Lafon (0.1 FTE)
Meeting Schedule Teleconferences: topic-specific calls may be held.
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.


Web Applications traditionally assume that the network is reachable, which is not always the case. The Working Group will specify event-driven services between the network layer and the application, allowing it to handle network requests gracefully even while offline.


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. The Working Group intends to publish the latest state of their work as Candidate Recommendation (with Snapshots) and does not intend to advance their documents to Recommendation (no expected milestones).

Normative Specifications

The Working Group will deliver the following W3C normative specifications:

Service Workers

This specification defines an API to enable applications to take advantage of persistent background processing.

Draft state: Candidate Recommendation Draft

Expected completion: Candidate Recommendation Snapshots

Adopted Draft: Service Workers, 12 July 2022.

Exclusion Draft: Service Workers 1, 19 November 2019.

associated Call for exclusion started on 2019-11-19, ended on 2020/01/18

Exclusion Draft Charter:

Other Deliverables

The Service Workers Working Group will determine the next steps for the following WICG specification, and may by group decision adopt it as a deliverable:

Background Fetch

An API to handle large uploads/downloads in the background with user visibility.

Draft state: Adopted specification from WICG

Next steps for Background Fetch may include promotion to Working Group deliverable (with agreed changes).

The following specifications are in scope for discussion and incubation within the Working Group, but formal publication on the Recommendation track would require re-charter to get consensus and commitments:

Web Background Synchronisation

This specification defines an API that uses Service Workers to permit both one-off and periodic synchronisation of data, for applications that use non-local data storage.

Draft state: Adopted specification from WICG

Web Periodic Background Synchronisation

This specification describes a method that enables web applications to periodically synchronize data and content in the background.

Draft state: Adopted specification from WICG

Next steps for those documents may include promotion to Working Group deliverables (via a new charter), or deprecation.

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.

Success Criteria

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

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

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

All new features should be supported by at least two intents to implement before being incorporated in the specification.

If a critical mass of key stakeholders and implementers of this technology do not join the group, its charter should be re-examined by the W3C.


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

Web Applications Working Group
This group enables improved client-side application development on the Web, including application programming interfaces (APIs) for client-side development.
Web Performance Working Group
This group provides methods to measure and improve aspects of application performance of user agent features and APIs.
Web Application Security Working Group
This group develops security and policy mechanisms to improve the security of Web Applications, and enable secure cross-origin communication.

External Organizations

ECMAScript Standards Body
The Web Hypertext Application Technology Working Group (WHATWG) is a community of people interested in evolving the web through standards and tests.


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 Service Workers Working Group home page.

Most 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, 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 02 August 2017 30 June 2019 none
Charter Extension 02 August 2017 31 December 2019 none
Rechartered 27 January 2020 30 June 2020

Rechartering adding one potential new deliverables: Background Fetch.

Charter Extension 17 June 2020 31 December 2020 none
Charter Extension 1 January 2021 31 March 2020 none
Chairs change 5 February 2021 - Matt Falkenhagen (Google Inc.) replacing Jungkee Song (Microsoft Corporation).
Rechartered 19 May 2021 31 October 2022 none
Rechartered 14 February 2023 31 January 2023 none

Change log

Changes to this document are documented in this section.