AMP Cache Updates

The following was originally posted on the Google Developers Blog by John Coiner, Software Engineer, Google.

Today we are announcing a change to the domain scheme of the Google AMP Cache. Beginning soon, the Google AMP Cache will serve each site from its own subdomain of This change will allow content served from the Google AMP Cache to be protected by the fundamental security model of the web: the HTML5 origin.

No immediate changes are required for most publishers of AMP documents. However, to benefit from the additional security, it is recommended that all AMP publishers update their CORS implementation in preparation for the new Google AMP Cache URL scheme. The Google AMP Cache will continue to support existing URLs, but those URLs will eventually redirect to the new URL scheme.

How subdomain names will be created on the Google AMP Cache

The subdomains created by the Google AMP Cache will be human-readable when character limits and technical specs allow, and will closely resemble the publisher’s own domain.

When possible, the Google AMP Cache will create each subdomain by first converting the AMP document domain from IDN (punycode) to UTF-8. Every “-” (dash) will be replaced with “–“(2 dashes) and every “.” (dot) will be replaced with a “-” (dash). For example, will map to Where technical limitations prevent a human readable subdomain, a one-way hash will be used instead.

Updates needed for hosts and service providers with remote endpoints

Due to the changes described above, CORS endpoints will begin seeing requests with new origins. The following updates will be required:

  • Expand request acceptance to the new subdomain: Sites that currently only accept CORS requests from and the publisher’s own origins must update their systems to accept requests from https://%5Bpub-com],, and the AMP publisher’s own origins.
  • Tighten request acceptance for security: Sites that currently accept CORS requests from https://* as described in the AMP spec, can improve security by restricting acceptance to requests from https://%5Bpub-com],, and the AMP publisher’s own origins. Support for https://* is no longer necessary.
  • Support for new subdomain pattern by ads, analytics, and other technology providers: Service providers such as analytics and ads vendors that have a CORS endpoint will also need to ensure that their systems accept requests from the Google AMP Cache’s subdomains (e.g., in addition to their own hosts.

Retrieving the Google AMP Cache URL

For platforms that display AMP documents and serve from the Google AMP Cache, the best way to retrieve Google AMP Cache URLs is to continue using the Google AMP Cache URL API. The Google AMP Cache URL API will be updated in Q1 2017 to return the new cache URL scheme that includes the subdomain.

You can use an interactive tool to find the Google AMP Cache subdomain generated for each site over at


Timing and testing resources

Google Search is planning to begin using the new URL scheme as soon as possible and is monitoring sites’ compatibility.

In addition, a developer testing sandbox is available at to help ensure a smooth transition. After making the updates described above, please use the sandbox to test accessing your site via Google Search. The sandbox loads AMP pages using the new domain scheme, so if you spot CORS-related errors in this configuration, these issues should be addressed to avoid errors when the domain scheme change is fully rolled out.

AMP Cache Updates

Teads brings AMP’d mobile video inventory to premium publishers

Editor’s note: The following was originally posted on Teads’ Blog by Eric Shih, Global Senior Vice President of Business Development

Video has more power to engage, educate, and entertain than any other medium. But it needs to be done right, especially when used as an advertising tool. A successful video ad brings the needs of the user, brand, and publisher into alignment. It’s useful, not intrusive. Complementary, not distracting. It needs to be viewable, high-quality, and of course, mobile-optimized.

This mobile-first approach led us to become one of the first ad technology companies to join the Accelerated Mobile Pages (AMP) Project, an open-source initiative to build a better, faster mobile web for everybody. The AMP HTML format empowers publishers to easily create mobile-optimized content that loads in a flash, offering a great user experience on every screen and platform. For technology companies like Teads, the AMP Project offers the opportunity to participate in a growing performance-based ecosystem as an advertising platform for a faster web.

As the inventor of outstream video advertising and the leading video advertising marketplace in the world, according to comScore, we knew it was important to follow the latest developments in technology. For us, that meant adapting our products to work with AMP HTML. This included updating our pioneering inRead format, which opens up vast quantities of premium video inventory by placing ads within the heart of editorial content. Instead of expanding into view and then collapsing away as the user scrolls, the video would always remain open in AMP HTML, ensuring a consistent page layout and seamless reading experience.

The updated format worked great, and it still had the advantage of being viewable while remaining subject to user control. Results were so positive, in fact, that we adopted AMP HTML’s behavior everywhere our ads appear – on desktop, mobile web, and in mobile apps.

Like us, many of our exclusive publisher partners have been part of the AMP Project since the very beginning. Now nearly 100 of them are telling great stories and sharing important ideas on fast-loading pages that meet users’ need for speed. These include Trinity Mirror, L’Express, Ouest-France, Público, Rodale, and Mashable, to name just a few.

“AMP HTML delivers our most optimal mobile browsing experience,” Amir Malik, programmatic director for Trinity Mirror, told us. “Being able to marry this with native video advertising allows us to not only make revenue from the fastest-growing area of digital but to do so while respecting our users.”

Along with these publishers, we’ve been delighted to see that video ads perform significantly better on AMP’d pages than on the traditional mobile web. Completion rates are 15% higher, clickthrough rates have jumped by 200%, and our ads appear 18% more frequently. This tells us that faster performance and relevant, respectful ads don’t just prevent abandonment and ad blocking — they also increase engagement.

If you’ve ever waited impatiently for your favorite site to load, only to watch an annoying pop-up take over your smartphone screen, you can probably understand why user engagement decreases. That type of experience doesn’t unlock the full potential of video advertising. We need a better approach, and the AMP Project is central to Teads’ mission of providing one.

Posted by Eric Shih, Global Senior Vice President of Business Development

Teads brings AMP’d mobile video inventory to premium publishers