In Silicon Valley, WhatsApp is usually filed under “Meta’s other messenger.” In São Paulo, Mumbai, Jakarta, Lagos and Mexico City, it is the operating system of daily life. The green icon installed on roughly three billion phones is where families coordinate their weekends, where small businesses take orders, where doctors send prescriptions, where teachers share homework, where political campaigns are won and lost, and where wholesale price lists circulate among bricklayers and beauticians who would never call themselves online sellers. WhatsApp’s quiet ubiquity has made it, by some measures, the most influential application of the post-Facebook decade — and yet it remains the least talked about in tech-press cycles dominated by short-form video and generative AI.

The Numbers Behind the Quiet

WhatsApp passed two billion monthly active users in 2020. Meta’s own filings now put the figure at approximately 2.9 billion. In several large markets, the application has effectively saturated the smartphone population. According to a 2024 Statista snapshot, more than 96 per cent of Brazilian smartphone owners had WhatsApp installed; the corresponding figures for India and Indonesia were 90 and 85 per cent respectively. In Mexico, Argentina and Italy the share sat above 90 per cent. The contrast with the United States, where WhatsApp’s smartphone penetration hovers around 30 per cent, is stark, and helps explain why the app is so persistently underestimated in English-language coverage.

What makes the figures more remarkable is the contrast between WhatsApp’s growth and its monetisation. Meta only began earning meaningful revenue from the app in 2018 with the launch of WhatsApp Business and the subsequent Cloud API. Even today, the entire family-of-apps reporting segment that includes WhatsApp generates a small fraction of Meta’s advertising revenue. By any normal silicon-valley metric, WhatsApp is undermonetised. By any normal anthropological metric, it has become indispensable to the digital lives of more people than any other app on Earth.

From Jan Koum’s Apartment to Meta’s Board Room

The application was founded by Jan Koum and Brian Acton in 2009 in Mountain View, California. Koum, who had emigrated from Ukraine as a teenager, designed the product around a simple principle: messaging should be cheap, reliable and ad-free. He famously kept a Post-it note above his desk that read “No ads! No games! No gimmicks!” Facebook acquired the company in February 2014 for nineteen billion dollars, the largest software acquisition in history at the time, and committed in writing to keeping WhatsApp ad-free. Koum departed Meta in 2018 amid public reporting of disagreements over privacy and monetisation; Acton left a year earlier and went on to fund Signal.

The acquisition was widely mocked in 2014 as the most expensive purchase of a “free” SMS replacement. With hindsight, it is regarded as one of the most strategically important acquisitions in technology, comparable to Google’s purchase of YouTube or Microsoft’s purchase of LinkedIn. By 2017 WhatsApp’s message volume already exceeded the entire global SMS network. By 2023 it processed more than one hundred billion messages a day according to Meta’s internal figures.

End-to-End Encryption: The Quiet Revolution Inside the Pipes

In April 2016, WhatsApp completed the rollout of end-to-end encryption by default, using the Signal Protocol developed by Open Whisper Systems. Almost overnight, more than a billion people had cryptographic guarantees on their everyday conversations. The change altered the global landscape for both privacy advocates and law-enforcement agencies. It also set the technical baseline against which every subsequent messenger has been measured.

Encryption has been a recurring flashpoint with governments. The United Kingdom’s Online Safety Act, India’s IT Rules of 2021 and several Brazilian judicial orders have at various moments pressed WhatsApp to provide traceability of forwarded messages or to weaken encryption for child-safety reasons. Meta has resisted, arguing — backed by independent cryptographers — that any backdoor for one purpose becomes a vulnerability for all purposes. The political tug-of-war is unresolved and is likely to define the application’s next decade as much as features ever will.

The Rise of Forwarded-Message Misinformation

WhatsApp’s privacy strengths also make it harder to police misinformation than open platforms like Facebook or X. The 2018 elections in Brazil and India brought global attention to the role of viral forwarded messages — sometimes mass-mailed by political operations — in spreading false claims. In response, WhatsApp introduced a series of forwarding limits: messages forwarded more than five times are tagged as such, and “highly forwarded” messages can only be sent to one chat at a time. These changes reportedly reduced the spread of highly forwarded content by around seventy per cent according to a study from MIT.

The structural problem remains. A message moves through end-to-end encrypted pipes, leaving no public trace; the platform cannot read it and therefore cannot identify it as misleading without breaking the same guarantees that protect dissidents, journalists and ordinary citizens elsewhere. WhatsApp has invested instead in tip-line partnerships with fact-checkers in dozens of countries, allowing users to forward suspect content for human verification.

WhatsApp Business and the Birth of the Conversational Economy

The decisive product change of the last five years was the launch of WhatsApp Business in 2018 and the more permissive Cloud API in 2022. Together they turned the messenger into a commercial channel for tens of millions of small businesses. In Brazil alone, more than seventy per cent of small and medium enterprises now use WhatsApp Business for at least part of their customer interaction, according to PagBrasil’s annual survey. In India, the Reserve Bank of India’s UPI integration made it possible to take payments inside the chat. In Mexico, WhatsApp Pay has been piloted with selected banks since 2023.

For larger brands, the Cloud API made conversational commerce industrial. Airlines send boarding passes, banks notify of low balances and confirm transactions, ride-hail platforms send driver-arrival updates, and supermarket chains take orders entirely inside the chat thread. Meta charges a per-conversation fee that varies by category and country; the company disclosed in its 2024 earnings reports that messaging revenue had crossed the one-billion-dollar annualised run-rate. It remains a sliver of total Meta revenue but the curve is steep.

Channels, Communities and the Slow Pivot to a Broadcaster

For years, WhatsApp resisted becoming a publishing surface. The 2023 introduction of Channels — public broadcast streams from a chosen handle to followers — marked a meaningful break with that posture. By mid-2024, more than four hundred million users had subscribed to at least one channel, according to a Meta announcement, and many high-traffic accounts belonged to football clubs, government press offices, religious organisations and celebrity musicians. Brazil’s Confederação Brasileira de Futebol, Spain’s La Liga and India’s Bollywood studios are among the heaviest channel publishers.

Channels have a careful design. They are explicitly one-to-many. Subscribers do not learn each other’s identities and cannot reply within the channel itself. From a privacy standpoint, this is far less invasive than X or Telegram broadcast groups. From a publishing standpoint, it begins to approximate a closed-loop newsletter, with the world’s largest audience already on the platform.

WhatsApp Communities and Group-Chat Governance

In November 2022, WhatsApp launched Communities, a structural layer that lets administrators bundle related group chats under a single umbrella with announcement broadcasts at the top. The product was an explicit answer to Discord and Telegram’s popularity among schools, churches, neighbourhood associations and political organisations. By the end of 2024 over one hundred million people were members of at least one Community, according to internal figures shared at the F8 developer event.

Communities also acknowledged a problem that had long lurked in the application: group chats had become so central to daily life that their lack of governance tools — moderation, sub-threads, role-based permissions — was a liability. Communities introduced a hierarchical structure without breaking the privacy posture of the underlying groups.

Voice, Video and the Pandemic Pivot

WhatsApp’s voice and video calling, rolled out incrementally between 2015 and 2018, became essential during the COVID-19 pandemic. In April 2020, the application briefly increased the participant cap on video calls from four to eight, and later to thirty-two, after observing more than seven hundred million daily voice and video minutes during peak lockdowns. The product was decisive in markets where Zoom and Google Meet did not have meaningful brand awareness outside corporate environments. For many older users in Latin America, Africa and South Asia, WhatsApp video calls were the first internet-based call they ever made.

A Different Notion of Social Networking

One way to read WhatsApp’s rise is as the slow displacement of the broadcast social network — the model invented by Twitter and Facebook — by the small-group conversational network. WhatsApp groups are intimate by default. They are populated by people you already know. They produce a different sociology of online attention: less performative, more transactional, more emotionally laden.

Studies from Pew Research in the United States and from the Reuters Institute in Europe and Latin America have documented that for younger users, the centre of gravity of online socialising has moved decisively to group chats. Many under-25s now describe Instagram and TikTok as “for content” and WhatsApp as “for people.” The application’s competitor set is therefore not really Telegram or Signal — it is the daily routines of three billion people, with which it has already merged.

Meta AI Inside the Chat

The latest substantive product shift is the integration of Meta’s Llama-based AI assistant into WhatsApp, rolled out across most markets through 2024 and 2025. The assistant can be invoked inline within any chat, can search the web and can generate images. For a population for which the app is already the default touchpoint with the internet, embedding a generative model directly inside it changes who has access to those tools. A user in a small Indian town who has never visited a search engine now has access to a state-of-the-art assistant within their primary communication application.

The launch has not been frictionless. European regulators have asked questions about data-protection compliance under the GDPR. Meta has paused the assistant’s deployment in the European Economic Area while it negotiates terms with national supervisory authorities. In the rest of the world, the assistant has reached more than five hundred million monthly users within twelve months, according to Meta’s most recent earnings call.

The Quietest Super-App

The technology press regularly asks which application will become “the WeChat of the West.” The answer may already be visible. WhatsApp is unlikely to acquire the same vertical integration of payments, ride-hail and identity that WeChat enjoys inside China, because the regulatory environment outside China would not allow it. But the foundation — universal installation, end-to-end-encrypted messaging, business profiles, payments in select markets, channels, communities and embedded AI — increasingly resembles a super-app distributed across multiple national regulators rather than concentrated under one.

The remarkable thing is how unflashy the rise has been. WhatsApp has never had a viral marketing campaign comparable to TikTok’s, never launched a celebrity influencer push, never built an attention-trapping algorithmic feed. It simply became reliable, encrypted and free, and it kept being all three things long enough for most of the world to make it the centre of their digital lives. Whatever Meta’s strategic emphasis on the metaverse or AI commands the next earnings call, the company’s most important asset will continue to be a green icon that almost everyone, almost everywhere, opens dozens of times a day without thinking about it.