Tuesday, August 18, 2020
Signed Exchanges (SXG) is a subset of the emerging family of specifications called Web Packaging, which enables publishers to safely make their content portable, while still keeping the publisher's integrity and attribution. In 2019, Google Search started linking to signed AMP pages served from Google's cache when available. This feature allows the content to be prefetched without loss of privacy, while attributing the content to the right origin.
Today we are happy to announce that sites implementing SXG for their AMP pages will be able to understand if there are any issues preventing Google from serving the SXG version of their page using the Google AMP Cache.
Use the AMP report to check if your site has any SXG related issues - look for issues with 'signed exchange' in their name. We will also send emails to alert you of new issues as we detect them.
To help with debugging and to verify a specific page is served using SXG, you can inspect a URL using the URL Inspection Tool to find if any SXG related issues appear on the AMP section of the analysis.
You can diagnose issues affecting the indexed version of the page or use the "live" option which will check validity for the live version currently served by your site.
To learn more about the types of SXG issues we can report on, check out this Help Center Article on SXG issues. If you have any questions, feel free to ask in the Webmasters community or the Google Webmasters Twitter handle.