Blue bubbles are best.

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Apple’s new iOS 26.5 update delivers “a new milestone for secure cross‑platform messaging,” the mobile standards agency GSMA said last week. The RCS upgrade that has now come to both iPhone and Android will “improve privacy and security.” So, why does Apple say iMessage and not RCS is still “best.”

GSMA says that for smartphone users, the RCS upgrade benefits are simple. “E2EE RCS messages can’t be read by anyone but the sender and receiver when they’re being sent between Apple and Android devices, even by Apple or Google.”

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This should provide users "with the highest level of privacy and security while messaging." But there’s a catch. That only happens , GSMA acknowledges, “once enabled by supporting mobile network operators." Only then will all those users “recognize the newly encrypted conversations via a padlock icon.”

GSMA is “now encouraging our members to leverage these new capabilities and enable more secure RCS messaging for personal and business users worldwide.” But that won’t happen quickly. It will be patchy. And that’s the issue.

Apple says that in contrast, “iMessage was built with privacy in mind and has always been end-to-end encrypted.” Every message flagged by those a blue bubble is secure. “It remains the best way to communicate between Apple devices.”

All RCS and MMS/SMS messages, regardless of encryption, “appear in green text bubbles on your device,” Apple says. “Learn how to have blue bubbles instead.”

GSMA describes the RCS encryption upgrade “as a collaborative industry effort involving Apple, Google and the GSMA to strengthen modern mobile messaging standards.” The reality, though, is that Apple never seemed that keen.

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This is much more critical to Google. The Android-maker came much later to the E2EE party with Google Messages, a platform it (ironically) used to drive adoption of RCS across Android, having grown frustrated with a slow carrier rollout.

We don’t yet know how fast this will actually happen, there’s a very complex global cellular ecosystem that must upgrade for this to really be “end-to-end.” Until then, Apple is clearly right. Blue bubbles remain the only certainty in its walled garden.