# Interop 2027 proposal selection process Interop 2027 is an effort to increase interoperability across browsers in key technical areas that are of high priority to web developers and end users. This effort is part of the [web-platform-tests](https://github.com/web-platform-tests/wpt) (WPT) project — an automated test suite for web standards — and run by a team of representatives from companies that make substantial contributions to browser rendering engines (including Apple, Google, Igalia, Microsoft, and Mozilla). Please see the [Interop 2026 Dashboard](https://wpt.fyi/interop-2026) and [Interop 2026 README](https://github.com/web-platform-tests/interop/blob/main/2026/README.md) for the current iteration of the project. Each iteration of the project starts with an open call for proposals, followed by a selection and prioritization process by each participating organization. Final decision on the inclusion of a proposal is made by [consensus](https://github.com/web-platform-tests/interop/blob/main/charter.md#:~:text=The%20team%20makes%20decisions%20based%20on%20consensus.%20A%20decision%20has%20consensus%20if%20it%20has%20support%20from%20at%20least%20two%20participating%20organizations%20and%20no%20opposition). For Interop 2027, the timeline and the selection process is as described below. ## Timeline This is the general timeline for the Interop 2027 proposal selection process. The dates are centered on the Interop team meeting (Thursdays). Please note that the timelines are subject to change. * Proposal submission window (~3 weeks): September 3rd, 2026 to September 23rd, 2026 * Proposal selection: Before December 10th 2026 * Scope of the Interop 2027 project published: February 4th, 2027. ## Proposal selection process The aim of the proposal selection process is to generate a shared understanding of the merits of each proposal, and converge on a decision about the most impactful areas in which we can improve interop on the web over 2027. As in previous iterations of Interop, details of proposal selection and ranking remain participant confidential throughout the process. Final decisions will be published as the Interop team. Confidentiality does not prevent participating organizations from sharing their own priorities or roadmaps, as distinct from positions in the proposal selection process. ### Prior to Proposal Submission **Timeline**: Before September 3rd 2026 The Interop team will develop a non-exhaustive set of signals/criteria that are considered important when assessing proposals. These will be shared with proposal authors so they can make their proposals stronger, and used later in the process when championing and assessing different proposals. However they are not binding on any specific participant i.e. participants are free to consider additional criteria (such as individual resource constraints) and weigh the shared criteria as they choose. ### Proposal Submission **Timeline**: September 3rd to September 23rd Members of the web community, including participants, will be invited to submit proposals for Interop 2027. These will take the form of issues on the Interop GitHub repository. Issue templates and documentation will be provided to guide proposers towards proposals that meet the formal criteria (e.g. around testability) and which can be assessed according to the agreed criteria. Items from Interop 2026 which have not yet reached full interoperability will be automatically resubmitted, and will go through the process as for any other proposal. In addition new proposals can be submitted that extend the scope of existing focus areas (whether or not they have reached full interoperability). As in previous years proposals can either be for focus areas or investigations. For simplicity the remainder of this document will only refer to focus area proposals, but this also covers proposals for investigation efforts. ### Champion Selection **Timeline**: September 23rd, October 1st, October 8th Interop participants propose focus areas, consisting of one or more proposals, that they would like to champion. Proposals will initially be shared in time for the meeting on October 1st, and champions finalised on October 8th. Where more than one participant wants to champion the same focus area proposal a single champion must be nominated for the remainder of the process. There is no assigned limit to the number of proposals one participant may champion. In case different focus areas are put forward with overlapping sets of proposals, the participants are encouraged to work out a way to divide the proposals into focus areas in a way that satisfies everyone. If this is impossible then carrying forward multiple competing focus area proposals is permitted, but final selections will only allow each proposal to appear in a single focus area. Any proposal without a champion will not be carried forward. ### Champion Evidence Gathering **Timeline**: October 8th, 15th Champions gather evidence of the impact of their proposals, using the rubric developed earlier. Specific participants may also be asked to provide (publicly available) information for all proposals where that participant has ownership of the information (e.g. standards positions, use counter data). ### Focus Area Proposal Presentation **Timeline**: October 22nd (double-length meeting) Each participant gets 15 minutes of meeting time to present the proposals they are championing, and make the case that they should be considered a priority for inclusion in Interop 2027. ### Proposal Ranking **Timeline**: Before November 19th Participants rank each proposal as P1 (highest priority) to P3 (lowest priority), or veto. There is no preset limit on how many proposals each participant may assign each rank. Initial rankings are submitted in time for the November 19th meeting. ### Focus Area Selection **Timeline**: December 3rd, 10th and 17th Focus areas with any vetoes are eliminated. Proposals that have strong positive consensus (e.g. majority P1 rankings, no P3 rankings) are adopted. Proposals with a strong consensus of low priority (e.g. many P3 ranking and no P1 ranking, or many P3 and P1 only from the champion) are dropped. Proposals with mixed rankings are ordered according to the number of P1 rankings, followed by the number of P2 rankings, followed by the number of P3 rankings. Starting from the top of the ordered list participants who ranked the proposal lower are given an opportunity to explain their concerns, and suggest any adjustments that would change their perspective. Proposal champions get final say on whether to adjust their proposals in response to this feedback. Following each meeting participants may adjust their rankings for the remaining proposals up or down in response to discussions, any agreed changes to the proposals, or the overall composition of the project, and the process repeats in the following meeting. Before the end of the December 18th meeting there's a final decision on any proposals without a clear resolution, and formal call for consensus on the set of selected focus areas. ### Communication and Publication **Timeline**: December 17th - February 4th 2027 Launch date is finalized. Focus area tests are labeled. Feedback for proposal authors written. ### Launch **Timeline**: February 11th 2027 The Interop 2027 dashboard is published. Proposal authors are provided with feedback and the original GitHub issues are closed. Participants publish announcements of the launch.