WhatsApp vs Arattai: Technical and Feature Comparison for Indian Users and Developers

Compare WhatsApp and Zoho Arattai side by side: their technical stacks, UI/UX features, security, business APIs, and Indian market share. Learn why to use or avoid each, and how to build a chat app like them.

The Indian messaging landscape is evolving fast. WhatsApp has dominated with its massive global user base, but homegrown apps like Zoho’s Arattai are now gaining traction thanks to privacy concerns and local support. In this article, we compare WhatsApp and Arattai deeply and technically, addressing both general users and developers. We’ll cover everything from backend infrastructure and encryption to UI/UX features like calls, chats, and file sharing. We’ll also explain why you might choose or avoid each app, explore the developer ecosystems (Business APIs, SDKs, integrations), and outline how to build a chat app like WhatsApp or Arattai – including recommended tech stacks, encryption practices, scalability options, and cost estimates. Finally, we’ll look at their market share in India and future roadmaps.

Arattai Technical Architecture & Infrastructure

Backend Stack and Cloud Infrastructure

WhatsApp’s backend is legendary for its simplicity and scalability. It is built primarily in Erlang, a language known for handling massive concurrency (Source). WhatsApp servers use this to manage millions of chat connections (each incoming TCP session is an Erlang process). The backend is split into many isolated clusters (over 40) for different services (chat routing, groups, media, etc.). In contrast, Zoho hasn’t publicly detailed Arattai’s stack, but Zoho products often use a mix of Go, Python/Deluge, and their own frameworks. Given Zoho’s focus on scale, it likely uses containerized services and may leverage Erlang or Go for messaging.

Cloud vs Local Data Centers: WhatsApp runs on Meta’s global infrastructure (data centers around the world), so user data can be stored internationally. Arattai, however, is fully hosted in India to comply with local data rules (Source). This means Arattai’s servers and databases reside in Indian data centers. Zoho is rapidly expanding Arattai’s capacity – after a 100× surge in traffic, it urgently added servers to handle new users. In the near term, both apps use cloud-like backends: WhatsApp on Facebook’s infrastructure, Arattai on Zoho’s (or possibly public cloud) but with promised data localization.

Server Locations & Scalability

WhatsApp’s architecture can handle huge scale: a single WhatsApp chat server can support over one million concurrent connections. Meta’s team designed it for resilience under load, using asynchronous messaging and process isolation so failures stay local. WhatsApp also recently introduced a new multi-device architecture allowing up to 4 companion devices per account (Source). Each device syncs independently with end-to-end encryption; messages are delivered by a “client-fanout” approach, encrypting each copy per device. Arattai also supports multi-device sync (around 5 devices including desktop and even Android TV apps (Source)), but details on how it syncs are scarce. Both apps need to scale: Arattai notably faced SMS OTP delays and login lags when millions joined, as Zoho hurriedly expanded infrastructure.

Encryption and Security

WhatsApp uses the Signal Protocol for true end-to-end encryption (E2EE) on all one-to-one chats and groups (Source). That means text, media, and calls are locked with unique keys that only the sender and recipient devices hold; even WhatsApp’s servers can’t read message content. By default, every private or business chat is secured this way unless a user or business opts into an optional cloud service.

Arattai’s approach is different today. According to Zoho’s public FAQs, only voice and video calls are E2EE; text messages are encrypted in transit and at rest on the server, but are not fully end-to-end (Source). In other words, Arattai encrypts data while moving and stores it securely, but it temporarily decrypts messages server-side for routing. Zoho says it is actively developing full message-level E2EE for Arattai (Source). For now, both apps use modern encryption: WhatsApp extends Signal’s double-ratchet with authentication, while Arattai uses strong encryption for calls and server storage. As of 2025, WhatsApp has stronger chat privacy, whereas Arattai is “almost there” on call security.

APIs and Developer Tools

WhatsApp and Arattai both offer ways for developers and businesses to integrate with them. The WhatsApp Business Platform provides an API for large-scale messaging. Businesses can send customer-initiated or template messages, use chatbots, and even embed commerce in chats. WhatsApp’s API supports text, images, location, list and reply buttons, and product catalogs for e-commerce. Meta also offers the WhatsApp Cloud API or on-premises API for self-hosting, complete with webhooks, templates, and support for notifications and authentication.

Arattai’s ecosystem is still growing. Zoho has built open APIs and SDKs into its platform: Arattai can integrate with Zoho Cliq (team chat) and with Zoho Flow for workflows (Source) (Source). For example, you can automate a Zoho Flow task to send a message to an Arattai channel; Zoho Flow advertises “Arattai integrations” with 1000+ apps. A third-party article confirms “Open API & SDK – Developers can embed Arattai into their apps or build custom connectors” (Source). In practice, Arattai leverages Zoho’s suite: it can post messages into channels, link chats to CRM records, and trigger actions from chat commands. As a result, businesses already using Zoho CRM, Desk, or other apps can seamlessly tie messaging into their workflows.

In summary, WhatsApp’s developer ecosystem is broad and mature: it has an official Business API, many third-party libraries, and integrations (e.g. marketing, bots) via partners. Arattai’s ecosystem is emerging: it currently uses Zoho’s own integration tools (Cliq and Flow) and promises more APIs and SDKs as it matures.

UI/UX and Feature Comparison

Let’s compare what users see and use. Both apps have the expected basics, but differ on details:

• Chats and Messaging: Both support one-to-one and group chats with text, emojis, voice notes, and media. WhatsApp’s interface is very polished and familiar worldwide. Arattai’s UI is clean and reportedly performs well even on older phones (Source). Arattai includes a unique “Pocket” feature (a private notes/memo pad) and an “Until I reach” location sharing, which WhatsApp doesn’t have. WhatsApp has a “Favorites” section (starred messages) and a “Delete for Everyone” feature; Arattai similarly allows editing and deleting chats. Both allow customizing profile photos and statuses.

Above: Screenshot of Zoho Arattai’s chat interface on a smartphone. Users see familiar elements like chat bubbles, file share icons, and a top bar with search. Arattai and WhatsApp both offer end-to-end encrypted voice and video calls with HD quality. WhatsApp has recently expanded group calls to up to 32 participants. Arattai supports group calls (voice/video) and conference mode, though its exact participant limit isn’t widely published. Both apps compress media to save data. On Android and iOS, WhatsApp and Arattai have very similar calling UI.

• Group Chats: WhatsApp allows up to 1024 members per group. Arattai currently caps group size at 1000 users (with phone numbers hidden in group contexts for privacy). This is comparable for most users. Both let admins broadcast announcements; Arattai calls them “Channels” for one-way updates, similar to WhatsApp’s Channels/Broadcasts.
• Media Sharing: WhatsApp lets users send all kinds of files and has a 2 GB file size limit. Arattai has a 1 GB limit, still generous. Both apps allow sending images, videos, audio, documents, and location. WhatsApp offers live location sharing. Arattai offers traditional location sharing and a neat “Till I reach” mode that automatically updates your moving location, a small plus for safety.
• Stories / Status: Both support ephemeral stories. WhatsApp’s Status lets you post text or pictures for 24 hours to all your contacts. Arattai calls them “Stories” and works similarly. Neither app publishes users’ stories publicly by default; they appear only to contacts or followers.
• Device Sync & Backup: WhatsApp originally required your phone to stay connected (until multi-device update). Now it allows using the app on 4 non-phone devices (PC, tablet) simultaneously, all synced via end-to-end encryption. WhatsApp also offers chat backup (on Google Drive or iCloud) – optionally encrypted with a user-defined key. Arattai similarly supports multiple devices: you can install it on phones, tablets, desktops, and even Android TV. It syncs contacts and messages across them (though a few users reported initial sync delays under heavy load). Arattai’s backup solution isn’t detailed publicly yet, but as a Zoho app it may leverage Zoho cloud storage for backups. Both apps now allow scanning QR codes on desktop to link devices.
• Unique Features: Some smaller features stand out. WhatsApp has Status highlights, group invite links, live photo/video calling with filters, and QR codes to add contacts. Arattai has built-in language support for many Indian languages, and an emphasis on running well on low-end devices and poor networks. It also hides group participants’ phone numbers to improve privacy. WhatsApp, being global, includes third-party integrations like payments (WhatsApp Pay in some countries) and business catalogs; Arattai’s strength is integration with Zoho’s productivity suite (for example, you can turn a chat into a CRM lead or send a chat message as an email via Zoho Flow).

The table below summarizes key differences:

Why Use WhatsApp

• Ubiquity and Network Effect: Almost everyone in India uses it – India alone has ~600 million WhatsApp users (Source). That means all your contacts and family are already there. It’s entrenched in daily life (personal chat, social groups, education, business communication).
• Mature Features: Years of development have made it stable and smooth. It has rich emoji/sticker support, location sharing, message editing/deletion, business catalogs, and global calling.
• Strong Encryption by Default: End-to-end encryption on by default for all chats and calls gives great privacy (except optional business cloud cases). Advanced privacy tools (like the 2025 “Advanced Chat Privacy” to block export) keep evolving.
• Global Ecosystem: Lots of integrations (WhatsApp Pay in India, chatbots, CRM plugins). Large developer community and third-party tools. Official Business API and many partners for customer engagement.
• Multi-Device Support: Now works offline with 4 companion devices; you can use on desktop, tablets, and the phone seamlessly.
• Free and Ad-Lite: No subscription or ads in the chat.

Why Use Arattai

• Data Privacy & Sovereignty: Arattai is “spyware-free, made-in-India”. It promises no user data mining and conforms to India’s privacy rules. Its servers are in India, so data doesn’t automatically go abroad. For privacy-focused users, this is a big plus.
• Optimized for India: Supports many Indian languages and works well on low-end phones and slow networks. If you have an older Android or limited bandwidth, Arattai is designed to perform.
• Seamless Zoho Integration: For businesses using Zoho tools, Arattai can link chats to CRM, support tickets, or projects. You can automate tasks via Zoho Flow (e.g. send alerts in Arattai when a support ticket is updated). This tight enterprise integration is unique.
• Modern UI and Features: It already offers core features – chat, group chat, HD calls, media sharing, stories, and channels (broadcasts). It even has an Android TV app. With endorsements from officials, early adopters describe it as polished and user-friendly (even calling it “India’s WhatsApp killer”).
• No Ads or Hidden Agenda: Zoho is profit-neutral on Arattai. There are no ads and the app is free. For users wary of Meta’s business model, Arattai’s straightforward privacy stance is appealing.

Why Not Use WhatsApp

• Privacy Concerns: Meta collects metadata on usage (who you message, when, from where) which it can use for ads. Some users worry about Facebook’s access (even if content is encrypted, data like your contacts and usage patterns are visible to Meta). This concern drives interest in local alternatives.
• Dependency on Phone: Although improving, WhatsApp still ties your identity to a phone number. If you lose your SIM or number, account recovery can be tricky. (Arattai also uses phone numbers, but its local backing may ease some concerns.)
• Regional Feature Gaps: WhatsApp channels or payments may not yet be available everywhere. It also can be heavy on low-end devices and data plans.
• Less Customization: WhatsApp has limited built-in workflows. Businesses need the paid Business API and external tools; in-app automation is minimal.

Why Not Use Arattai

• Smaller Network: Arattai is new and few people use it yet. If none of your contacts are on it, you’ll need to convince friends/family to switch. WhatsApp’s network effect is a huge moat.
• Encryption Still Evolving: As of 2025, Arattai lacks end-to-end encryption for text chats. Privacy-minded users may hold off until full E2EE is implemented. Zoho says it’s coming, but it’s not there yet.
• Feature Gaps: Arattai is still adding features. For example, it doesn’t have payment integration or a super-streamlined business API. Occasional bugs and sign-up lags were reported during its first popularity wave. Early users had to endure OTP delays and server hiccups as Zoho ramped up.
• Perception and Marketing: Some may distrust a “government-endorsed” app or worry it’s experimental. Arattai is currently in a “beta feel” phase. If Zoho can’t keep improving, users might lose interest.

Developer Ecosystem & Integration

WhatsApp Business API: Enterprises can apply for WhatsApp’s Business Platform. The API supports automated customer service, two-way auth, appointment reminders, and promotions via interactive message templates. There are SDKs and libraries (Java, Node.js, Python) available. Developers must follow Meta’s business messaging policy and opt users in before messaging them. Popular CRM and ticketing systems (Zendesk, HubSpot, etc.) offer built-in WhatsApp connectors.

Arattai Integration: While Zoho hasn’t released a public developer API (in 2025), it has provided connectors within its ecosystem. Zoho Flow enables no-code workflows: for instance, you can automate sending an Arattai message when a Google Sheet is updated, or vice versa. Zoho Cliq (chat) has an Arattai widget allowing messages to flow between Arattai and Cliq. A third-party article notes Arattai’s “Open API & SDK” that lets developers embed its chat into custom apps. Expect Zoho to expand this: they plan to publish messaging protocols and support interoperability, which implies more open API access.

Integration Tools: WhatsApp also offers integration via WhatsApp Business API (on-prem or cloud) and is compatible with automation platforms like Twilio or Zapier. Arattai currently integrates into Zoho’s suite. Zoho Flow supports Arattai triggers/actions (e.g. “Post message to channel” action exists). This means a company using Zoho CRM can push updates into Arattai or react to Arattai messages with CRM updates.

Comparison: For developers, WhatsApp is a stable, well-documented platform – though it has usage costs and policies. Arattai is newer, but if your stack is already in Zoho/JavaScript/Node, integrating through Flow and Cliq may be simpler and possibly free. As Arattai opens up more, it could offer REST APIs similar to Zoho’s other services. For now, though, developers should view Arattai as “in its infancy” but promising, especially in Indian enterprise contexts.

How to Build a Chat App Like WhatsApp or Arattai

Drawing from both architectures, here’s our advice for building a similar messaging app:

• Frontend: Use native SDKs for best performance (e.g. Swift for iOS, Kotlin/Java for Android). For quick development, React Native or Flutter can work. Use reliable UI libraries for chat bubbles. Implement real-time communication using WebSockets (or Socket.IO) for instant message delivery (Source). Use APNs/FCM for push notifications. Keep the UI simple and responsive, and support local languages for India.
• Backend Language: Choose a language built for concurrency and scalability. WhatsApp uses Erlang (and FreeBSD OS). Modern alternatives include Elixir (on Erlang VM), Go, Rust, or Node.js with clustering. Whichever you pick, design it to handle many socket connections.
• Protocol: You can use existing protocols: XMPP (Ejabberd) is one option (WhatsApp historically used Ejabberd). Or use a custom TCP-based protocol optimized for speed. For encryption, integrate a Signal Protocol library (like libsignal) to secure messages like WhatsApp. Always encrypt messages in transit (TLS) and consider E2EE for content.
• Database & Storage: Use a combination of databases: an in-memory or fast key-value store (Redis, Mnesia) for online session state and message queues, and a persistent DB (Cassandra, PostgreSQL, MongoDB) for storing chat history and metadata. Store media files (photos, videos) in blob storage (AWS S3, Google Cloud Storage or on-prem Object Storage). Use CDN for media caching.
• Infrastructure & Scalability: Host on cloud (AWS, GCP, Azure) in local regions (Mumbai/Delhi) for Indian users. Use auto-scaling groups and load balancers. Partition services by function (e.g. chat server cluster, media server cluster). Consider using containers or Kubernetes for orchestration. For quick notification delivery and message queuing, use a message broker (Kafka, RabbitMQ, or MQTT).
• Encryption Practices: Use AES-256 for media and files at rest. For message encryption, implement end-to-end key exchange via Diffie-Hellman (as in Signal protocol). Keep private keys off the server. Secure connections with TLS. In India, end-to-end encryption is a plus for privacy-conscious users.
• Cost & Timeline: A simple chat app (text chat, basic groups) can be built in 2-3 months with a small team, often costing $25K–35K (₹20–30 lakh) (Source). Adding features like voice/video calls, encryption, multi-device sync, and admin tools can extend it to 6–12 months and $50K+. Note costs vary greatly by team location and scope. Using open-source messaging servers can cut costs. You’ll also need budget for cloud hosting (which can scale up as users grow) and for maintenance.
• Cloud vs Local Data Center: For India-focused apps, consider using an Indian cloud region (AWS Mumbai, Azure Central India, etc.) or even a local data center to comply with data localization laws. This can add cost, but it earns user trust. Compare it to using a global cloud: local deployment can have higher setup cost, but offers latency and legal benefits.

In summary, building a WhatsApp/Arattai-like app requires solid real-time architecture, robust encryption, and continuous iteration. With the right tech stack and investment, it’s feasible. Many startups choose proven stacks like Node.js + WebSocket + Redis/Cassandra + React Native or Elixir + Phoenix Channels + PostgreSQL. From our experience at Make An App Like, focus on the fundamentals (reliable messaging, good UX, privacy by design), then add features.

Market Share and Adoption in India

WhatsApp’s dominance in India is enormous. As of late 2024, India had over 500 million monthly WhatsApp users (some sources even estimate ~600M or higher). That’s roughly half the country’s population on one chat app! It outstrips any other service in India by a wide margin. WhatsApp’s messages and calls power everything from family chats to government bulletins in India.

Arattai’s footprint is tiny by comparison, but it’s growing. Launched in January 2021, Arattai had only a small user base initially. By October 2025, Zoho claimed it crossed 1 million total users. At its peak buzz in Sept 2025, Sensor Tower reported 400,000 downloads in one month versus only ~10,000 the month before. Daily sign-ups jumped from ~3,000 to 350,000 in a few days after official endorsements. The narrative of a “Made-in-India” chat app boosted adoption. However, even 1–2 million users is a rounding error next to WhatsApp’s base.

In business and institutional use, WhatsApp Business (including the UPI-integrated payments) is widely used in India, despite regulatory challenges. Arattai is mainly seeing usage in education and government communications right now. Its long-term market share will depend on whether it can convert downloads into regular use and attract communities (education, SMEs, public sector) to migrate.

Future Outlook and Planned Updates

WhatsApp Outlook: WhatsApp continues evolving. In 2025 it introduced Advanced Chat Privacy (to block chats from being forwarded or used by AI). Future updates are expected to include more encryption and privacy tools, cross-app interoperability (via Meta’s unified messaging), and possibly localized features. In India specifically, WhatsApp might further integrate local payments or commerce features when regulations allow. Meta’s annual roadmaps hint at more business-friendly features, improved backups, and AI-driven smart replies.

Arattai Outlook: Zoho is actively investing in Arattai’s roadmap. They plan to open up their messaging protocols – aiming for interoperability with other apps (like UPI did for payments). This suggests Arattai might eventually link up with other Indian messengers. Crucially, Zoho is working on full end-to-end encryption for text (which they’ve confirmed is coming). They’re also likely to expand local language support, offline capabilities, and user growth features. Zoho’s 25-year R&D culture means they’ll add features steadily. Importantly, Zoho can leverage its AI and SaaS expertise: expect things like AI chatbots in Arattai (respecting privacy) or deeper CRM integration. As they scale, they’ll focus on stability (handling millions reliably).