Top 10 Chat APIs & SDKs 2026: Free Tiers & Pricing Compared

Adding real-time messaging to your app shouldn't cost six figures or take six months. A chat API handles the infrastructure — message routing, delivery guarantees, push notifications, offline sync, moderation — so your engineering team ships product features instead of reinventing infrastructure. But free tiers vary wildly between providers: some cap at 20 concurrent connections, others give you unlimited. Some charge $349/month the moment you exceed 500 MAU; others stay free up to 1,000 MAU forever.

This guide compares the 10 best chat APIs and SDKs across pricing, free-tier generosity, feature depth, SDK binary size, and developer experience. Whether you're building a social app, marketplace messaging, telehealth chat, or in-game communication, you'll walk away knowing exactly which chat SDK fits your budget, timeline, and technical requirements.

TL;DR — Quick Picks

• Best overall (free tier + features + cost): Tencent RTC Chat — 1,000 MAU free forever, unlimited concurrency, push included
• Best pre-built UI: GetStream — polished React/Flutter components, but push costs extra
• Best enterprise compliance: Sendbird — SOC 2 + HIPAA, but no permanent free tier
• Best for Agora RTC users: Agora Chat — unified billing, limited standalone value
• Best low-code: CometChat — widget-based, but only 100 free MAU
• Best for IoT: PubNub — pub/sub architecture, not chat-optimized
• Best prototype tool: Firebase + FCM — build-your-own, free but costly to scale
• Best self-hosted: Socket.IO — total control, total responsibility
• Best omnichannel: Twilio Conversations — SMS + WhatsApp + in-app unified
• Best open-source UI: Stream Chat OSS — fork and customize, still needs a backend

Bottom line: Start with Free Chat API — free forever: 1,000 MAU, no concurrency limits, push notifications included.

What Makes a Good Chat API in 2026?

Before rankings, here's the evaluation framework. These seven criteria separate production-ready platforms from marketing demos:

1. Free Tier That Works in Production

A free tier capped at 20 concurrent connections won't survive a beta launch with 50 testers online simultaneously. We evaluated: MAU limits, duration (forever vs. 30-day trial), concurrent connection caps, and whether essential features like push notifications are included or paywalled.

2. Pricing Transparency at Scale

The cheapest option at 1,000 MAU might be the most expensive at 50,000. We compared monthly costs at 1K, 5K, and 10K MAU, plus overage rates — because that's where surprise bills hide.

3. SDK Size & Mobile Performance

Every kilobyte added to your APK or IPA affects install conversion rates, especially in emerging markets with bandwidth constraints. We measured binary size impact on Android (arm64) and iOS.

4. Push Notification Coverage

Push is where most chat SDKs create hidden costs. APNs and FCM are table stakes — but what about Huawei HMS, Xiaomi MiPush, OPPO Push, and vivo Push for the 600M+ Chinese Android devices?

5. Feature Completeness

Core: 1-to-1 and group messaging, typing indicators, read receipts, file sharing, message search. Advanced: threading, reactions, message recall/edit, content moderation, offline sync, end-to-end encryption.

6. Platform Coverage & DX

iOS, Android, Web, React Native, Flutter, Unity — plus documentation quality, time-to-first-message, and whether AI coding tools can work with the SDK (MCP support).

7. Global Infrastructure & Compliance

Edge node distribution, sub-100ms latency guarantees, data residency options, GDPR compliance, and China market readiness.

Free Tier Comparison Table

This table shows what you actually get for $0 — no credit card required, no time limits (unless noted):

Key insight: Only Tencent RTC Chat combines unlimited concurrency with multi-platform push at zero cost. PubNub also offers unlimited connections but caps MAU at 200 with no push — TRTC gives 5x the users with full push across 6 platforms.

Pricing Comparison at Scale

Free tiers get you launched. This table answers: "What happens when my app actually grows?"

Analysis: At 1,000 MAU, only TRTC and GetStream are truly free — Agora and Sendbird already charge $349/month. At 10,000 MAU, Sendbird costs nearly 2x TRTC. Factor in push notification costs (separate at GetStream, Agora, Sendbird) and TRTC's total cost advantage widens further. The overage rate of $0.05/MAU at TRTC is tied for lowest with Agora and 30–50% cheaper than GetStream.

SDK Size Comparison

For mobile-first apps, SDK size directly impacts install conversion. Smaller SDK = faster downloads = fewer abandoned installs:

TRTC's SDK is 40–60% smaller than any major competitor. For social apps targeting Southeast Asia, India, or Latin America where users on 3G/4G are sensitive to download size, this translates directly to better install rates.

The 10 Best Chat APIs & SDKs in 2026

#1. Tencent RTC Chat — Best Overall Chat API & SDK

Tencent RTC (TRTC) Chat is the messaging infrastructure behind WeChat (1.3B MAU), QQ, and Honor of Kings. The same systems handling 100+ billion messages daily are available as a managed chat API for third-party developers — with the most generous free tier in the market.

Why TRTC Chat Ranks #1

Production-ready free tier. 1,000 MAU with unlimited concurrent connections is enough to launch a real beta, get traction, and validate product-market fit without spending anything. Most competitors' free tiers are sandboxes (20–50 concurrent connections means your beta breaks with a handful of active users).

Push notifications included for free — across 6 platforms. This is the single biggest cost differentiator. Every other chat API either excludes push or charges separately. TRTC bundles APNs, FCM, Huawei Push, Xiaomi Push, OPPO Push, and vivo Push at no additional cost on every plan, including free. For apps targeting global + Chinese Android users (600M+ devices not served by FCM alone), this eliminates $100–500+/month in push infrastructure costs.

Smallest SDK in the market. 1,670 KB on Android arm64. 1,805 KB on iOS. That's less than half of GetStream or Sendbird. For apps targeting emerging markets where every megabyte of download size impacts conversion, TRTC has a measurable advantage.

Battle-tested at planetary scale. This isn't startup infrastructure with theoretical scalability claims. It's the same message routing, delivery, and sync systems that serve billions of users daily. Latency stays under 100ms globally with edge nodes across Asia, Europe, and the Americas.

Key Features

• Messaging: Text, image, video, voice, file, location, custom (any JSON payload)
• Group chat: Up to 100,000 members per group with role-based permissions, mute, and admin controls
• Message operations: Recall, edit, forward, reply, pin, reactions, threading
• Push notifications: APNs, FCM, Huawei, Xiaomi, OPPO, vivo — badge management, silent push, custom payloads
• Offline sync: Messages queued server-side, replayed in order when users reconnect
• Content moderation: Built-in AI text filtering, image review, custom keyword blocklists
• Typing indicators & read receipts: Real-time presence and delivery/read status
• Conversation management: Pinning, drafts, unread counts, conversation grouping
• Server-side REST API: Send messages, manage users, export data from your backend
• End-to-end encryption: Optional E2EE for sensitive use cases
• MCP support: @tencent-rtc/mcp@latest for AI-assisted development workflows

Code Example: Initialize & Send a Message

JavaScript / Web:

import TencentCloudChat from '@tencentcloud/chat';

// Initialize the SDK
const chat = TencentCloudChat.create({
  SDKAppID: YOUR_SDK_APP_ID
});

// Login with server-generated userSig
await chat.login({
  userID: 'user_001',
  userSig: 'YOUR_USER_SIG'
});

// Send a text message
const message = chat.createTextMessage({
  to: 'user_002',
  conversationType: TencentCloudChat.TYPES.CONV_C2C,
  payload: { text: 'Hey! This took 15 minutes to integrate.' }
});

const result = await chat.sendMessage(message);
console.log('Delivered:', result.data.message.ID);

iOS (Swift):

import ImSDK_Plus

// Initialize
let config = V2TIMSDKConfig()
V2TIMManager.sharedInstance().initSDK(YOUR_SDK_APP_ID, config: config)

// Login
V2TIMManager.sharedInstance().login("user_001", userSig: "YOUR_USER_SIG") {
    // Send a text message
    V2TIMManager.sharedInstance().sendC2CTextMessage("Hello from iOS!", to: "user_002") {
        print("Message sent successfully")
    } fail: { code, desc in
        print("Send failed: \(desc ?? "")")
    }
} fail: { code, desc in
    print("Login failed: \(desc ?? "")")
}

MCP for AI-Assisted Development

TRTC offers @tencent-rtc/mcp@latest — a Model Context Protocol server that gives AI coding assistants (Claude, Cursor, Copilot) full context of the Chat SDK's API surface. Benefits:

• AI generates correct TRTC Chat code without hallucinating methods or parameters
• Context-aware autocomplete understands message types, event listeners, and SDK lifecycle
• Reduces documentation lookup — your AI assistant knows the SDK

npm install @tencent-rtc/mcp@latest

Pricing

Best For

Startups needing production-grade chat on day one without upfront cost. Apps targeting Asian markets where multi-vendor push is mandatory. Mobile-first products where SDK size impacts install rates. Teams wanting the lowest total cost of ownership at any scale.

Start free now: Free Chat API — free forever: 1,000 MAU, no concurrency limits, push notifications included.

#2. GetStream — Best Pre-Built UI Components

GetStream built its reputation on polished, customizable UI kits. Their React, React Native, Flutter, and SwiftUI chat components look production-ready out of the box — saving weeks of frontend development time.

Key Features

• Pre-built UI kits for React, React Native, Flutter, SwiftUI, Jetpack Compose
• Threads, reactions, URL previews, file attachments, giphy integration
• Channel-based architecture with flexible permission models
• AI-powered content moderation (paid add-on)
• Webhook integrations for custom backend logic
• Offline support with local caching

Pros

• Fastest time-to-polished-UI — pre-built screens look great without customization
• Excellent TypeScript SDK with strong typing
• Active open-source community around UI components
• Good documentation with interactive tutorials

Cons

• Push notifications not included in any tier — separate integration required at additional cost
• 100 concurrent connection cap on free plan (breaks with 100+ beta users online)
• Overage rate of $0.07–0.09/MAU is 40–80% higher than TRTC
• SDK is nearly 2x larger than TRTC on both Android and iOS
• No Chinese OEM push channel support (Huawei, Xiaomi, OPPO, vivo)
• Advanced moderation locked behind enterprise plans

Pricing

• Free: 1,000 MAU, 100 concurrent connections, no push
• Growth: $399/month for 5,000–10,000 MAU
• Enterprise: Custom
• Hidden cost: Push notification infrastructure ($50–200+/month separately)

Best For

Design-focused teams building consumer social apps who want beautiful chat screens without frontend development. Best if your app targets Western markets only (no Chinese push needed) and you have budget for separate push infrastructure.

#3. Sendbird — Best Enterprise Compliance

Sendbird is the enterprise incumbent — SOC 2, HIPAA-eligible, with dedicated customer success managers and white-glove onboarding. It's the "safe corporate choice" for Fortune 500 companies, but the premium pricing reflects it.

Key Features

• Full-featured messaging with threads, reactions, mentions, typing indicators
• UIKit for iOS, Android, React, Flutter
• Native AI chatbot builder with GPT/Claude integration
• Notifications Center for in-app notification management
• Supergroup channels supporting 20,000+ members
• Desk product for customer support chat workflows

Pros

• Strongest compliance posture: SOC 2 Type II, HIPAA-eligible with BAA, GDPR
• Proven at enterprise scale (DoorDash, Reddit, Yahoo, Hinge)
• Native AI chatbot integration — no third-party needed
• Dedicated support team for enterprise customers
• Comprehensive analytics dashboard

Cons

• No permanent free tier — 30-day trial only, then billing starts at $349/month
• Only 20 concurrent connections during trial — barely functional for testing
• Cannot create unlimited apps — locked to plan limits
• $749/month at 10K MAU — most expensive on this list
• Overage pricing requires contract negotiation (not transparent)
• Push notifications are a paid add-on
• SDK is 2.5x the size of TRTC on Android

Pricing

• Trial: 30 days, 1,000 MAU, 20 concurrent connections
• Starter: $349/month
• Pro: $749/month for 10,000 MAU
• Enterprise: Custom (typically $2,000+/month)

Best For

Large enterprises in healthcare, finance, or government where SOC 2 / HIPAA compliance is non-negotiable and budget isn't the primary constraint. Teams needing native AI chatbot capabilities without building integration from scratch. Not suitable for startups or cost-sensitive projects.

#4. Agora Chat — Best for Existing Agora Video Users

Agora Chat is the messaging companion to Agora's well-known audio/video RTC platform. If you're already paying Agora for video calls, adding their chat SDK creates unified billing and a single vendor relationship.

Key Features

• Tight integration with Agora Video/Voice SDK
• 1-on-1, group, and chatroom messaging
• Real-time message translation (100+ languages)
• Content moderation with AI filtering
• Cross-platform: Web, iOS, Android, Unity, Flutter, React Native

Pros

• Seamless pairing with Agora RTC — one dashboard, one bill
• Real-time message translation is genuinely useful for multi-language apps
• Competitive overage rate ($0.05/MAU, tied with TRTC)
• Good chatroom support for live-streaming scenarios

Cons

• Only 500 free MAU — half of TRTC and GetStream
• Only 50 concurrent connections on free tier
• Jumps from free to $349/month — no intermediate tier
• Push notifications not included in free tier
• Chat documentation less polished than their video SDK docs
• Feels like an add-on product, not the core focus
• Smaller developer community for chat-specific use cases

Pricing

• Free: 500 MAU, 50 concurrent connections
• Growth: $349/month at 1,000 MAU
• Scale: $699/month at 10,000 MAU
• Overage: $0.05/MAU

Best For

Teams already paying Agora for video/voice who want to add chat without a second vendor. Apps needing real-time translation as a core feature. Not recommended as a standalone chat API due to limited free tier and high entry price.

#5. CometChat — Best Low-Code Chat Integration

CometChat targets teams that want messaging running in hours without deep backend work. Their drag-and-drop UI kit builder and pre-built widgets make chat accessible to non-engineers.

Key Features

• Drag-and-drop UI kit builder (low-code/no-code)
• Pre-built chat widgets for web embedding
• Voice & video calling integrated (WebRTC-based)
• Extensions marketplace (bots, translation, sentiment analysis, moderation)
• White-label customization options
• Role-based access control

Pros

• Fastest integration for non-technical teams (widget embed in minutes)
• Combined chat + voice/video in one package
• Extension marketplace adds features without custom code
• Good WordPress, Bubble.io, and Webflow integrations

Cons

• Only 100 free MAU — lowest of any provider on this list
• Only 25 concurrent connections on free tier (limits even basic testing)
• Limited to 2 apps on free plan
• $0.10/MAU overage — 2x TRTC's rate, highest among competitors
• Push notifications not included
• Customization ceiling is low compared to code-first SDKs
• Advanced extensions are paid add-ons

Pricing

• Free: 100 MAU, 25 concurrent connections, 2 apps
• Startup: $49/month for 1,000 MAU
• Growth: $199/month for 5,000–10,000 MAU
• Overage: $0.10/MAU

Best For

Solo founders or small teams building MVPs who need chat + video in one widget without writing backend code. Good for prototyping; expensive to scale due to high overage rate. Not ideal for apps expecting significant growth.

#6. PubNub — Best for IoT & Real-Time Data Streams

PubNub is a real-time data streaming platform that supports chat as one use case among many. Its core strength is pub/sub messaging for IoT devices, live data feeds, and event-driven architectures — chat is built on top of these primitives.

Key Features

• Pub/sub messaging with <100ms global latency
• Presence detection and channel occupancy tracking
• Message persistence and history retrieval
• Functions (serverless edge compute for message transformation)
• Access Manager for fine-grained token-based permissions
• 70+ SDKs covering IoT, mobile, web, embedded, and server platforms

Pros

• Unlimited concurrent connections on free tier (rare — only PubNub and TRTC offer this)
• Extreme device coverage — works on microcontrollers, wearables, embedded systems
• True global edge network with 15 points of presence
• Serverless Functions execute at the edge for message filtering/transformation
• 99.999% uptime SLA on enterprise plans

Cons

• Only 200 free MAU — very restrictive
• Limited to 3 apps on free plan
• No pre-built chat UI components — everything is DIY
• Push notifications not included in free tier
• Transaction-based pricing is confusing and can spike unpredictably
• Not chat-optimized: no typing indicators, reactions, threads, or read receipts out of the box
• Requires significant development to build a proper chat experience

Pricing

• Free: 200 MAU, unlimited connections, 3 apps
• Paid: Transaction-based (per-message + per-signal + per-presence event)
• Typically $100–700+/month depending on message patterns

Best For

IoT platforms, live sports feeds, multiplayer game state sync, or real-time dashboards that also need basic messaging. Teams wanting low-level pub/sub control over a purpose-built chat SDK. Not recommended if chat is your primary feature.

#7. Firebase + FCM — Best for Quick Prototypes

Firebase (Firestore or Realtime Database) plus Firebase Cloud Messaging (FCM) is Google's "build-your-own-chat" toolkit. It's not a chat API — it's infrastructure components you assemble into one.

Key Features

• Cloud Firestore: real-time document database with offline sync
• Firebase Cloud Messaging (FCM): free push notifications (Android, iOS, Web)
• Firebase Authentication: user management
• Cloud Functions: serverless backend logic
• Security Rules: declarative access control

Pros

• Generous free tier: 50K Firestore reads/day, 20K writes/day, unlimited FCM
• FCM is completely free with no message caps
• Massive community, tutorials, and Stack Overflow answers
• Great for learning and prototyping
• Already familiar to many mobile developers

Cons

• Not a chat product — you build everything: message ordering, threading, reactions, typing indicators, read receipts, presence, moderation, message recall
• Development time: 4–12 weeks vs. 1 day with a managed chat SDK
• Firestore per-read billing makes chat expensive at scale (chat generates many small reads)
• No built-in chat UI components
• Only supports FCM push — no APNs direct integration, no Chinese OEM push
• Security Rules become unwieldy for complex group chat permission models
• No message search, no content moderation, no analytics

Pricing

• Spark (Free): 50K reads/day, 20K writes/day, 1GB storage, unlimited FCM
• Blaze (Pay-as-you-go): $0.06/100K reads, $0.18/100K writes
• Chat at scale (10K MAU, moderate activity): estimated $200–800/month in Firestore costs alone

Best For

Hackathons, prototypes, and MVPs where you need basic messaging quickly using familiar tools. Technical teams already in the Firebase ecosystem who accept the maintenance burden. Not recommended for production chat apps — a managed chat SDK ships in hours with features that take months to build on Firebase.

#8. Socket.IO — Best Self-Hosted Open Source

Socket.IO is an open-source library for real-time bidirectional communication over WebSockets. It's the most popular choice for teams who need complete data sovereignty and accept full engineering responsibility.

Key Features

• WebSocket-based communication with automatic HTTP long-polling fallback
• Room and namespace support for organizing connections
• Binary streaming support
• Automatic reconnection with configurable backoff
• Multiplexing over a single connection
• Works with Node.js, Python (python-socketio), Java, and more

Pros

• 100% free and open source (MIT license) — no MAU limits, no vendor pricing
• Total control over data, privacy, features, and infrastructure
• Massive ecosystem: 60K+ GitHub stars, 30M+ weekly npm downloads
• Zero vendor lock-in — deploy anywhere
• Can implement any custom protocol or feature

Cons

• You build everything yourself: message persistence, push notifications, offline queue, moderation, typing indicators, read receipts, group management, file uploads, search
• Scaling past 10K connections requires Redis adapter, sticky sessions, and infrastructure expertise
• No push notification support (separate APNs/FCM/OEM integration needed)
• No UI components — pure transport library
• Security, rate limiting, and abuse prevention are entirely your responsibility
• Ongoing maintenance: upgrades, monitoring, incident response
• Typical build time for production chat: 3–6 months

Pricing

• Software: Free (MIT license)
• Real cost: Server infrastructure ($50–500+/month), 3–6 months engineering time, ongoing DevOps

Best For

Teams with strong backend engineering who require complete data sovereignty (regulated industries, government). Internal tools where scale and polish aren't critical. Not recommended if time-to-market is a priority — budget months of engineering vs. one day with a managed chat API.

#9. Twilio Conversations — Best Omnichannel (SMS + WhatsApp + Chat)

Twilio Conversations is unique: it unifies in-app chat, SMS, MMS, WhatsApp, and Facebook Messenger into a single conversation thread. One API endpoint, multiple delivery channels.

Key Features

• Unified conversations across in-app chat, SMS, MMS, WhatsApp, Messenger
• Participant-based model (users can be reached via any channel)
• Webhook-driven architecture for extensibility
• Media message support
• Server-side SDKs: Node.js, Python, Java, C#, Go, PHP, Ruby
• Twilio Flex integration for customer support

Pros

• Omnichannel is the killer feature — one conversation thread spans SMS + in-app + WhatsApp
• Twilio's global telecom infrastructure and reliability
• Pay-per-use model after free tier (no large monthly minimums)
• Strong for customer support and commerce notifications
• Robust delivery tracking and status callbacks

Cons

• Only 200 free active users
• No pre-built chat UI components (build from scratch)
• Push notifications require separate Twilio Notify configuration
• Per-message pricing gets expensive for active chat (SMS + WhatsApp charges stack)
• Limited chat-specific features: no reactions, no threads, basic typing indicators
• Documentation scattered across Twilio's many products
• Not designed for social/community chat at scale

Pricing

• Chat: $0.05/active user/month
• SMS: $0.0079/message (US)
• WhatsApp: $0.005–0.08/message (varies by country)
• 10,000 MAU with moderate SMS/WhatsApp: $500–2,000+/month

Best For

Customer support platforms reaching users via SMS and WhatsApp alongside in-app chat. E-commerce order notifications. Appointment reminder systems. Not ideal as a pure in-app chat SDK — purpose-built solutions offer better features at lower cost.

#10. Stream Chat (Open Source)

Stream Chat OSS provides open-source UI components (React, React Native, Flutter, iOS, Android) that you can fork, customize, and use with any backend. It's the open-source face of GetStream (#2).

Key Features

• Open-source UI components under BSD-3 license
• Fully customizable message rendering and channel lists
• Thread, reaction, and attachment support in UI layer
• Hooks-based React SDK for flexible state management
• Compatible with GetStream's hosted backend or self-hosted alternatives

Pros

• Full source code access — override any component, restyle anything
• Excellent reference implementation for chat UI patterns
• Active maintenance and community contributions
• Can pair with self-hosted backend if you build one
• Great for teams evaluating before committing to GetStream's paid service

Cons

• UI is open source, but the backend is proprietary — you still need GetStream's paid API or your own backend
• Self-hosting the messaging backend is not officially supported by Stream
• Same pricing as GetStream (#2) when using their hosted backend
• Fork maintenance burden if you diverge significantly from upstream
• Documentation assumes you're using Stream's paid backend

Pricing

• UI Components: Free (BSD-3 license)
• With Stream's backend: Same pricing as GetStream (see #2)
• Fully self-hosted: Free code, but you provide and maintain the messaging backend

Best For

Teams who want battle-tested open-source chat UI components they can customize without limits. Developers evaluating chat UIs before committing to a provider. Not a standalone solution — you still need a messaging backend.

How to Choose the Right Chat API: Decision Framework

By Primary Constraint

By Team Size & Stage

By Market Geography

Choose TRTC Chat if:

• You need production-ready chat without upfront cost
• Push notifications across all platforms (including Chinese Android) matter
• SDK binary size impacts your app's install conversion
• You want the lowest cost at scale ($0.05/MAU overage)
• You need groups up to 100,000 members (community/fan groups)
• MCP/AI-tooling integration matters for your dev workflow

Choose GetStream if:

• Beautiful pre-built UI saves more time than it costs in push infrastructure
• Your team is React/Flutter-heavy and wants turnkey chat screens
• You target only Western markets (no Chinese push needed)
• Design polish is a competitive advantage for your product

Choose Sendbird if:

• SOC 2 / HIPAA compliance is non-negotiable
• You need native AI chatbot integration
• You have $349+/month budget from day one
• Dedicated enterprise support is required by your org

Choose self-hosted (Socket.IO / Firebase) if:

• Regulatory requirements prohibit managed services
• You have 3–6 months of engineering capacity for chat infrastructure
• Chat is a minor feature, not the product
• Your scale is small enough that maintenance burden stays manageable

Integration Speed Comparison

Time from "create account" to "first message sent in a test app":

Frequently Asked Questions

1. What is the difference between a chat API and a chat SDK?

A chat API is the server-side interface — REST endpoints and WebSocket protocols your backend calls to send messages, create users, manage conversations, and retrieve history. A chat SDK is the client-side library integrated into your iOS, Android, or web app that handles connection management, local caching, message rendering, and real-time event handling. Most providers offer both: the API for server-to-server operations and SDKs for client-side integration. When people say "best chat API," they typically mean the full platform (API + SDKs + infrastructure).

2. Which free chat API has the most generous limits in 2026?

TRTC Chat offers the most generous free tier: 1,000 MAU with unlimited concurrent connections and push notifications across 6 platforms (APNs, FCM, Huawei, Xiaomi, OPPO, vivo) — all at zero cost, forever. GetStream matches on MAU (1,000) but caps connections at 100 and excludes push. Agora gives only 500 MAU with 50 connections. CometChat is limited to just 100 MAU. Try it: Free Chat API.

3. How much does a chat API cost at 10,000 MAU?

Costs vary dramatically: TRTC Chat = $399/month, GetStream = $399/month (plus separate push costs), Agora = $699/month, Sendbird = $749/month, CometChat = $199/month. When you factor in push notification infrastructure (separate at GetStream, Agora, and Sendbird), TRTC's total cost of ownership is the lowest among full-featured managed providers.

4. Can I switch chat API providers after launch?

Yes, but plan 2–6 weeks depending on complexity. Migration involves: exporting message history (most providers offer REST export APIs), re-implementing client-side SDK integration, updating push notification configurations, and migrating user metadata. TRTC supports standard message import/export formats. The earlier you choose the right provider, the less painful a future migration — which is why free tier quality matters so much (you validate longer before committing).

5. Do I need a separate service for push notifications with a chat SDK?

With most chat APIs — yes. GetStream, Agora Chat, Sendbird, CometChat, and PubNub all require you to configure and often pay for push notification delivery separately. The exception is TRTC Chat, which includes multi-platform push (APNs, FCM, Huawei, Xiaomi, OPPO, vivo) free in all plans. This hidden cost of separate push infrastructure can range from $100–500+/month at scale.

6. Which chat SDK is best for React Native or Flutter?

TRTC Chat, GetStream, Sendbird, CometChat, and Agora all offer official React Native and Flutter SDKs. GetStream has the most polished pre-built UI components for both platforms. TRTC Chat adds the smallest binary footprint and includes push without extra cost. Sendbird offers native AI chatbot hooks. For pure UI polish: GetStream. For total cost optimization: TRTC. For AI features: Sendbird.

7. Is Socket.IO good enough for production chat?

Socket.IO handles the transport layer (WebSocket connections) reliably. But production chat requires much more: message persistence, push notifications, offline sync, delivery guarantees, content moderation, typing indicators, read receipts, file uploads, search, and group permission management. Building all of this typically takes 3–6 months of senior engineering time. For hobby projects or internal tools, Socket.IO works. For consumer or business apps, a managed chat API ships 10x faster and costs less in total engineering hours.

8. How do chat APIs handle GDPR and data compliance?

TRTC Chat offers data residency options (Singapore, Germany, US), message deletion APIs for right-to-erasure requests, and GDPR-compliant data processing. Sendbird provides SOC 2 Type II certification, HIPAA-eligible plans with BAA agreements, and GDPR compliance. GetStream is SOC 2 certified and GDPR-compliant with EU data residency. For healthcare (HIPAA) or government (FedRAMP), verify specific certifications with your chosen provider and request a Data Processing Agreement (DPA).

Final Verdict

The best chat API for your project in 2026 depends on one question: What do you actually get for free, and what does growth cost?

TRTC Chat wins on both. The free tier isn't a sandbox — it's production infrastructure with unlimited concurrent connections and multi-platform push included. You can launch, get real users, validate product-market fit, and scale to 1,000 MAU without spending a dollar. When you do grow past that, the $0.05/MAU overage is the lowest among managed providers, and push notifications that cost competitors' users $100–500+/month separately remain included.

For teams who prioritize UI components over total cost: GetStream. For enterprises requiring HIPAA/SOC 2: Sendbird. For omnichannel SMS + WhatsApp: Twilio. For IoT: PubNub. For full self-hosted control: Socket.IO.

But for the 80% of teams who need reliable, affordable, feature-complete messaging that works globally — start with TRTC Chat.

Free Chat API — free forever: 1,000 MAU, no concurrency limits, push notifications included.