Signal just got a big upgrade that beats WhatsApp

The Signal app logo displayed on an iPhone, with a screenshot of the Signal app in use displayed on a monitor in the background.
(Image credit: DANIEL CONSTANTE/Shutterstock)

Signal Private Messenger, the encrypted messaging app, just got a notable feature upgrade that tops WhatsApp, at least in terms of numbers.

Thanks to a new service that was developed in-house, Signal now supports up to 40 participants on an end-to-end-encrypted group video call, while WhatsApp is stuck at a maximum of eight.

"There is no off-the-shelf software that would allow us to support calls of that size while ensuring that all communication is end-to-end encrypted, so we built our own open source Signal Calling Service to do the job," wrote Signal's Peter Thatcher in a company blog post yesterday (Dec. 15).

The rest of Thatcher's post gets into the technical details, which we'll leave out here. (As Signal is an open-source project, the code for the Signal Calling Service  is available on GitHub for anyone's use.)

But as Android Police's Manuel Vonau  points out, Signal could support only five participants when the service added group video calls a year ago, so this is a huge ramp-up. 

It certainly leaves WhatsApp in the dust, as that Facebook-owned — sorry — Meta-owned service can handle only eight end-to-end-encrypted video-call participants at once. Both are way ahead of Telegram, which is slowly rolling out group video calls that have a current limit of 30 participants but are not end-to-end encrypted.

That means that while the video-call transmissions are encrypted between each participant and Telegram's servers, Telegram can still see what's going on. 

WhatsApp and Signal, on the other hand, can't — because the call content is visible only to persons on either end of the transmissions.

If you don't mind the possibility that the hosting service might be able to see what you say online — and provide recordings to the authorities, if warranted — then Telegram is a fine option, given that it has so many other features to offer. But if you'd rather not anyone else know your business, then Signal or WhatsApp it will have to be.

Check out our list of the best encrypted messaging apps for more information.

Paul Wagenseil

Paul Wagenseil is a senior editor at Tom's Guide focused on security and privacy. He has also been a dishwasher, fry cook, long-haul driver, code monkey and video editor. He's been rooting around in the information-security space for more than 15 years at, SecurityNewsDaily, TechNewsDaily and Tom's Guide, has presented talks at the ShmooCon, DerbyCon and BSides Las Vegas hacker conferences, shown up in random TV news spots and even moderated a panel discussion at the CEDIA home-technology conference. You can follow his rants on Twitter at @snd_wagenseil.