Question on CR Timeline

[yks0000]

Hi — I am Yogesh, and we are currently rolling out NEL across our Key Origins to gain browser-reported observability into DNS, TLS, and connection-layer failures at scale.

We've been building on the current Report-To + NEL header contract and it's working well in production. While evaluating wider adoption internally, a few questions about the spec's standardization trajectory came up:

1. Is there a rough timeline or plan to advance NEL to Candidate Recommendation? We noticed 5 Working Draft updates in Feb–Mar 2025 which suggests active momentum — curious if CR is on the near-term roadmap.

2. Are there any known open issues or planned changes that would affect the current Report-To + NEL header contract? Specifically anything that would require production deployments to change their header values or collector endpoint behaviour.

We're committed to the current implementation — the Chrome implementation has been stable for years — but a clearer picture of the spec status would be helpful.

Thanks for the continued work on this.

[nicjansma]

Hi @yks0000!

Wonderful to hear you're using NEL at scale!

The Web Performance Working Group owns the NEL spec which is currently in Working Draft (WD). We have not been able to move it towards Candidate Recommendation (CR) yet as there have been some challenges to wider adoption beyond Chrome.

The other browser vendors' primary concerns with adoption centers mostly around privacy concerns.

We discussed NEL in the WebPerfWG in depth at TPAC 2025 a few months ago. It was a good session (the link contain the discussion and summary), but the high level details are:

• There are multiple parties (from browser vendors to CDNs to commerical sites) that have an interest in moving NEL forward; we've created an informal working stream to try to push it forward
• There was no active editor for the spec (as the original authors had moved on to other projects). Luckily, we have @aluhrs13 and @guohuideng2024 from Microsoft who have stepped up to take over as editors in January of this year.
• There was some progress made at TPAC around the privacy concerns raised by Apple and Mozilla. We came up with an informal plan that would reduce the granularity of some of the data in NEL reports which would reduce the privacy concerns significantly. Those changes have not yet been drafted though.

As far as planned changes, I think the current header structure works well as-is, and I'm not aware of any significant proposals to change it. But there are some spec issues with where/how it's defined, e.g. #159