The Duo team began rolling out v26 today, but this one doesn't have any obvious changes, so it may be a service update. A teardown is also fairly sparse, mostly calling back to some older topics, including the upcoming feature for sending video messages when connections can't be made on the spot, the removal of some camera adjustments used in development, and the start of H.265 testing. Since there's not a lot of meat to most topics, they'll be kept pretty short. Of course, if you stumble across anything new, let us know in the comments!

What's New

Unofficial Changelog: (the stuff we found)

  • Dragable mirror button (from v25)

Mirror button

Alongside the release of v25.1, some UI changes were spotted rolling out to some users. This was immediately followed by the discovery that Duo could initiate calls to users without Duo installed. Later that same day, we were also tipped that the little floating view from your front facing camera, which I'm calling the mirror button, was no longer locked to the bottom left corner, but can now be dragged to different corners of the screen. It wasn't really a big enough change to warrant yet another post – we like to keep the noise level down – so we decided to wait until v26 to mention it.


Disclaimer: Teardowns are based on evidence found inside of apks (Android's application package) and are necessarily speculative and usually based on incomplete information. It's possible that the guesses made here are totally and completely wrong. Even when predictions are correct, there is always a chance that plans could change or may be canceled entirely. Much like rumors, nothing is certain until it's officially announced and released.

The features discussed below are probably not live yet, or may only be live for a small percentage of users. Unless stated otherwise, don't expect to see these features if you install the apk.

H.265 testing

I don't usually mention it, but the Duo developers have tested a few different streaming codecs in the past. Why mention it now? Mostly because there's something of a fanbase for h.265, which is well justified given that it's a widely supported standard on modern chipsets and delivers extremely good compression compared to h.264.

<string name="pref_h265x_title">Use H265x</string>
<string name="pref_h265x_dlg">Use H265x</string>
<string name="pref_h265x_key">h265x_preference</string>

from /xml/preferences.xml
<ListPreference android:entries="@array/autoOrBooleanValues" android:layout="@layout/settings_preference" android:title="@string/pref_h265x_title" android:key="@string/pref_h265x_key" android:defaultValue="@string/pref_value_auto" android:dialogTitle="@string/pref_h265x_dlg" android:entryValues="@array/autoOrBooleanValues" />

There's not a lot more to say about it than that. I've tried forcing h265 to be enabled and there's no discernable difference, at least not on my connection, so.... There ya go.

Follow-up: Videomail / Messaging

If you've read about the voicemail-like feature we've covered in previous teardowns, there's not much added in this version. The tl;dr is that Duo users will be able to send video messages to other contacts without connecting a call. Recipients will be able to watch these messages, save them for later, or delete them. The new lines don't add any new information to this, and most are basically redundant. Nevertheless, I point it out because there's still some movement on this topic and it looks like Duo will now also double-check for camera and microphone permissions before recording a message, just in case users didn't already grant it.

<string name="callee_is_unavailable">%s is unavailable. Leave a message.</string>
<string name="leave_message_text">Leave a message.</string>
<string name="stop_record_clip_button_text">Stop recording</string>
<string name="send_clip_button_text">Send</string>
<string name="camera_permission_clip_dialog_message">To send messages, give camera access first.</string>
<string name="microphone_permission_clip_dialog_message">To send messages, give microphone access first.</string>
<string name="send_message_error_notification_body">Tap to open Duo</string>
<string name="contact_item_description_clip">Play message from %1$s</string>
<string name="play_clip_button_text">Play message</string>
<string name="save_clip_button_text">Save</string>
<string name="close_clip_button_text">Close</string>
<string name="delete_clip_button_text">Delete</string>
<string name="notification_body_for_failed_message">Not enough device space to view message</string>
<string name="notification_title_for_failed_message">New message from %s</string>
<string name="snackbar_no_internet_connection">No internet connection</string>

Follow-up: Google sign-in

If you're waiting on Google sign-in to enable calling friends and contacts with their email address rather than a phone number, you'll probably have to wait a bit longer. On the plus side, there are still some tweaks and changes to strings, so there may still be some work remaining before it's ready to launch.

<string name="gaia_account_removed">%s signed out from this device</string>
<string name="gaia_account_signin">Sign in</string>
<string name="gaia_auth_error">Sign in to use Duo</string>
<string name="gaia_auth_error_details">Can't receive or make calls until you sign in</string>

I'm not going to say there's no new information in here, but one line does imply that you may now have to sign into a Google account to make or receive calls, whereas this was expected to be an optional step in the past. We'll have to wait and see if this actually becomes a requirement or not.

Follow-up: Camera adjustments removed

A few months ago, the Duo developers added some internal settings for adjusting the camera image. This began with color effects, white balance, and exposure controls. A couple months and four versions later, three more were added: Brightness, contrast, and saturation.

The following month saw those original settings removed, but the more recently added settings remained. And with this update, we've come full circle to see the brightness, contrast, and saturation settings removed. Since all of these were for internal use, it hardly impacts anybody directly, but it might hint that the developers have finished experimenting with these settings and there may be improvements or features coming as a result.


The APK is signed by Google and upgrades your existing app. The cryptographic signature guarantees that the file is safe to install and was not tampered with in any way. Rather than wait for Google to push this download to your devices, which can take days, download and install it just like any other APK.

Version: 26.0.182808076.DR26.1_RC09

Google Duo
Google Duo
Developer: Google LLC
Price: Free