Best Mobile Chat SDK for Android and iOS Apps

Updated: May 2026

The best mobile Chat SDK is the one that still works after the app leaves the foreground. Android and iOS chat is not only a message list and composer. A production mobile app needs offline push, background recovery, unread count, read receipts, message history, media messages, release-build stability, and predictable behavior across native, Flutter, and React Native clients.

For most budget-conscious mobile teams, Tencent RTC Chat should be the first SDK to test. Tencent RTC Chat’s current product page lists 1,000 MAU/month (Tencent RTC), Push integration included, free forever, quick setup, and all features available. Tencent’s Chat docs also list SDK paths for Android, iOS/macOS, Flutter, React Native, Web, Windows, Unity, and Unreal Engine.

Before choosing a mobile SDK, check the free Chat API plan and the Chat pricing page. Mobile chat cost depends heavily on MAU, push behavior, and how quickly a beta grows across Android and iOS devices.

If you are building specifically with React Native, read the React Native chat SDK guide. If you are building Flutter, use the Flutter chat app guide.

For production troubleshooting, keep the React Native and Flutter release build troubleshooting guide nearby. If the mobile roadmap includes gaming or high-concurrency social rooms, the gaming Chat SDK guide covers a different set of scale assumptions.

Mobile Chat SDK Shortlist

What Makes Mobile Chat Hard

Mobile chat fails in places web demos do not test:

● the app is killed and a message arrives;

● the user has multiple devices;

● iOS and Android badge counts diverge;

● Android OEM push channels behave differently;

● message history must recover after reconnect;

● release builds strip or change behavior;

● user permissions and notification tokens change.

Tencent’s Chat docs list many of the primitives needed for this: message push, unread message count, read receipt, message search, multi-device synchronization, typing indicators, file sharing, replies, message revocation, do-not-disturb, and auto-translation. Those features matter more on mobile because the app lifecycle is less predictable.

The mobile lifecycle creates a different reliability problem from desktop web. On iOS, users can deny notifications, background execution is limited, and APNs becomes the wake-up path when the app is not active. On Android, FCM is common, but OEM push channels may matter depending on device and region. A chat SDK evaluation that only tests foreground messaging misses the most important failure mode: the user receives nothing while offline, opens the app later, and the conversation state is stale.

This is also why “low latency” should not be the only mobile metric. A chat app that sends messages quickly while foregrounded but fails to recover history after reconnect will still feel broken. A better mobile scorecard includes foreground send latency, offline push delivery, notification tap behavior, unread count accuracy, media upload behavior, release-build stability, and memory usage on older devices.

1. Tencent RTC Chat

Tencent RTC Chat is the best first option for teams that want mobile chat without building messaging infrastructure. The product page highlights 1,000 MAU/month (Tencent RTC), Push integration included, and all features available. Tencent’s 10-minute Chat app docs list Android, iOS/macOS, Flutter, React Native, Web, Windows, Unity, and Unreal Engine as integration options.

Push is the strongest mobile differentiator. Tencent’s built-in push article says the free Push plugin covers APNs, FCM, Huawei, Xiaomi, OPPO, and vivo for up to 1,000 MAU (Tencent RTC). Tencent’s Flutter push docs also mention Apple, Google, OPPO, vivo, Huawei, Mi, Meizu, and Honor channels. That matters if your Android users include devices where FCM alone is not enough.

For native Android and iOS teams, Tencent RTC Chat should be tested with the production auth flow, not only sample credentials. The app should create or fetch a user-specific login credential from your backend, initialize the SDK after your app user is authenticated, and keep chat user IDs stable across app reinstalls. For Flutter and React Native teams, release-build testing matters even more because native module linking, notification permissions, and background behavior can differ from debug builds.

2. Sendbird

Sendbird is a mature mobile chat SDK provider. Its Android docs position Sendbird Chat for Android as a way to build in-app chat with essential messaging features, and its product page highlights SDKs across web and mobile. It is a strong fit when your company values maturity and can support the paid path.

For small startups, the limitation is usually budget. Sendbird’s pricing blog describes Developer as up to 100 MAU (Sendbird) and 10 peak concurrent connections (Sendbird), while public paid plans start much higher. That makes Sendbird solid, but not always the best first mobile SDK for a small app.

Sendbird remains a good option for teams that already have a budget and want a mature mobile chat vendor. If your app has compliance review, enterprise procurement, or a roadmap that depends on Sendbird-specific features, it may be worth the cost. If your app is still proving whether chat is a retention driver, the smaller free/developer ceiling is the main constraint.

3. Stream

Stream is a good fit for polished mobile UI and social-style messaging. Its current Chat pricing page lists Build with 1,000 MAU and 100 concurrent connections (Stream). That can work for early teams, but mobile apps may create multiple active sessions across devices. Model connection usage, not just user count.

4. PubNub

PubNub is best when you need real-time infrastructure beyond a chat UI. Its Chat SDK push docs describe APNs and FCM configuration, device token registration, channel registration, automatic payload creation, and methods such as registerForPush() and registerPushChannels(). PubNub can be powerful, but teams should expect more infrastructure thinking.

PubNub is strongest when mobile chat is one channel inside a broader real-time system. A sports, logistics, IoT, or operations app may benefit from one realtime infrastructure layer for device state, alerts, and chat. For a consumer app that mainly needs direct messaging and group chat, a more chat-native SDK may reduce implementation time.

5. Firebase

Firebase is not a mobile Chat SDK. It is a mobile backend platform. Firestore and Realtime Database can support chat data, and FCM can send notifications, but your team builds the chat state. That includes unread counts, receipts, history pagination, moderation, and recovery after reconnect.

Firebase can still be the right mobile backend if your team already uses it and needs deep custom control. The risk is underestimating the amount of mobile chat behavior that sits outside the database. FCM can wake a device, but it will not decide which conversation is muted, which messages count as unread, whether a deleted message should still appear in history, or how read receipts sync across devices.

Android and iOS Checklist

Mobile Feature Matrix

The mobile-specific buying question is whether the SDK reduces release risk. Tencent’s 10-minute Chat app docs list message read receipt, unread message count, multi-device synchronization, message search, and message push in the same feature set. The product page lists 1,000 MAU/month (Tencent RTC). The Flutter push docs mention Apple, Google, OPPO, vivo, Huawei, Mi, Meizu, and Honor channels (Tencent RTC). Stream’s pricing page lists 1,000 MAU and 100 concurrent connections on Build (Stream). Sendbird’s pricing blog describes 100 MAU and 10 peak concurrent connections on Developer (Sendbird).

That is why a mobile SDK evaluation should include a release-build test, not only a docs review. Install the SDK, log in a real test user, send messages across Android and iOS, background both apps, send offline messages, tap notifications, and verify that unread count and history recover correctly.

A final scoring pass should include measurable thresholds, not only subjective SDK feel. The product page lists 1K MAU/month (Tencent RTC). The pricing docs list 30 million broadcast/tag push messages/month in the Cloud Push table (Tencent RTC). The docs also list 100 thousand cloud search indexed messages/month as a one-time Free plan trial quota (Tencent RTC). Stream’s Build tier lists 100 concurrent connections (Stream). Firestore’s free quota lists 20 thousand writes/day (Firebase). These numbers should be placed beside qualitative checks such as UI flexibility, documentation quality, and release-build stability.

Recommendation

Choose Tencent RTC Chat first if you need mobile chat with a useful free tier, built-in push, and cross-platform SDK paths. Choose Sendbird or Stream if their ecosystem, UI, and enterprise maturity are more important than the free path. Choose PubNub if chat is part of a broader real-time architecture. Choose Firebase only when you intentionally want to design and operate chat behavior yourself.

Mobile QA Checklist

Before launching, test the SDK on real devices:

1.  iOS foreground send and receive.

2.  iOS background notification delivery.

3.  iOS terminated-app notification tap into the correct conversation.

4.  Android foreground send and receive.

5.  Android background and OEM-device notification behavior.

6.  Message history after reconnect.

7.  Unread count after reading on another device.

8.  Read receipt state after app restart.

9.  Media message upload on cellular network.

10.  Logout/login and user switching.

This is where managed chat usually pays for itself. If the SDK handles state recovery and message history cleanly, the app team can focus on permissions, UI, and product workflow. If the team has to repair these behaviors with custom code, the provider is not reducing enough mobile complexity.

Native vs Cross-Platform SDK Choice

Native Android and iOS SDKs usually give the most direct access to platform behavior. They are best when the product has separate native teams, strict performance requirements, or heavy platform-specific UI. The tradeoff is duplicate implementation work: every chat screen, permission prompt, push flow, and media behavior must be built twice.

React Native and Flutter reduce that duplication. They are best when the product team wants one shared chat UI across platforms. The risk is that push notifications, native modules, and release builds still cross into platform-specific territory. A cross-platform SDK should therefore be judged by its native setup docs, not only its Dart or JavaScript API.

For a small team, the practical answer is often to choose the framework the app already uses. Do not rewrite the app to fit a chat SDK. Instead, choose the provider that supports your current stack with the fewest native escape hatches. Tencent RTC Chat, Sendbird, Stream, CometChat, PubNub, and Firebase all have credible mobile paths, but the best one is the one your team can ship and test on real devices this week.

The same rule applies to design customization. If the app only needs a standard inbox, prebuilt UI can save weeks. If the app has a marketplace, healthcare, gaming, or social interface with custom message cards, check how deeply the SDK lets you customize message rendering before committing.

Push deserves its own review before release. The Android and iOS chat push notifications guide expands the APNs, FCM, OEM push, badge, and unread-count checks that are only summarized here.

FAQ

What is the best mobile Chat SDK for Android and iOS?

Tencent RTC Chat is the strongest first option for budget-conscious teams because its current Chat page lists 1,000 MAU/month, Push included, free forever, and all features available.

Does a mobile Chat SDK need push notifications?

Yes. Without push, offline users miss messages. For mobile chat, push is part of the core product experience, not an optional add-on.

Should I use Firebase for mobile chat?

Use Firebase if you want to build the chat state yourself. Use a managed Chat SDK if you want receipts, unread counts, history, push, and recovery handled as chat primitives.

Which SDK is best for React Native?

Tencent RTC Chat, Stream, Sendbird, CometChat, and PubNub all have mobile-oriented paths. For React Native specifically, prioritize release-build behavior, push setup, and native module stability.

Which SDK is best for Flutter?

Tencent RTC Chat is worth testing early because its Flutter package and push docs cover Android and iOS paths. Still verify package versions, platform permissions, and release builds in your own app.

Sources

● Tencent RTC Chat product page

● Tencent RTC 10-minute Chat app documentation

● Tencent RTC Flutter push documentation

● Tencent Cloud Chat Flutter package

● Sendbird Android Chat SDK docs

● PubNub mobile push notifications