Real-Time Communication

An Alibaba Cloud development platform that delivers real-time audio and video communication services worldwide

Real-Time Audio and Video Communication with High Quality

Real-Time Communication (RTC) uses cutting-edge audio and video encoding and decoding, real-time transmission, and network scheduling technologies to deliver highly available, high-quality audio and video communication services with ultra-low latency. RTC helps you develop multi-device, real-time applications for scenarios such as online education, video conferencing, interactive entertainment, and audio and video social networking.

RTC relies on the core technologies of ApsaraVideo, such as intelligent noise reduction algorithms, Narrowband HD™, and real-time transmission algorithms, to deliver high-quality communication services in noisy environments with unstable network connections and a packet loss rate of up to 80%.

Global Communication Services

Based on Global Real-Time Transport Network (GRTN), RTC allows you to access services in the nearest region. RTC uses intelligent scheduling, basic network optimization, and real-time transmission algorithms in combination with the network characteristics of major countries to provide you with low-latency communication services worldwide.

Real-Time Media Processing

Based on ApsaraVideo Global Real-Time Transcode Process (GRTP), RTC supports a variety of basic media processing features, such as stream mixing, transcoding, stream ingest, and recording. RTC uses cloud processing and rendering technologies based on real-time transmission to provide various features, such as rendering, effects, and streaming on the cloud. In addition, RTC relies on multimedia computing acceleration and hybrid resource scheduling technologies to provide cost-efficient real-time media services with high efficiency.

Secure Media Transmission

Your device must pass multiple admission verifications and multi-dimensional authentication of channel sessions to access services. Also, signaling and media data are encrypted and protected at the transport layer to ensure the transmitted audio and video data cannot be parsed externally. This ensures system security and data security during media transmission.

Scenarios of RTC

True-to-Life Meeting

The "Cloud ME" technology brings people, who cannot meet physically due to specific restrictions, closer together by using life-sized, true-to-life projection. You can enjoy immersive experience of real-time conversations and interactions.

Learn More about Alibaba "Cloud ME" >


  • Cloud ME Booth Setup with Ease

    Thanks to the power of cloud computing, a Cloud ME booth only needs typical studio equipment, such as a video camera and a computer used to capture the footage. The booth does not require additional onsite IT infrastructure or optimized Internet bandwidth to perform recording and transmission.

  • True-to-Life Projection

    After transcoding, rendering, scene reconstruction, and light and shadow processing based on cloud technologies, full-body images are projected to generate true-to-life hologram effects on a screen.

  • Immersive Interaction

    You can enjoy low-latency immersive interactions in true-to-life meetings with the same experience as daily conversions and interactions.

Live Show

RTC supports traditional video interactive streaming scenarios and features, such as cross-channel co-streaming, multi-player audio and video co-streaming, relayed livestreaming, and cloud-based recording. RTC enriches the content of live shows and fully mobilizes viewers to participate in live shows using various interactive methods. This improves the retention rate and conversion rate of viewers.


  • Stable and Reliable Services

    With network coverage in six continents, RTC allows devices to access services in the nearest region. RTC also provides comprehensive QoS policies to ensure the user experience in unstable network environments.

  • Comprehensive Features

    RTC supports features such as relayed livestreaming, cloud-based recording, basic retouching, and cross-channel streamer challenge.

Voice Chatroom

A voice chatroom is composed of the owner, streamer, and viewer roles. The owner and streamer can make real-time voice calls with each other, and viewers can participate in voice interactions.


  • Access from Multiple Platforms

    RTC supports access from multiple platforms, such as the web, Android, iOS, macOS, Windows, Linux, Unity, and mini programs.

  • High-Quality Audio Experience

    RTC supports binaural stereo audio and a full-band audio sampling rate at 48 kHz.

  • Support for Multiple Social Networking Features

    RTC provides special features, such as accompaniment music, sound effects, reverb effects, and voice changing.

Related Services

Online KTV

RTC simulates offline karaoke boxes and provides interactive features, such as solo, chorus, and listening to build online karaoke boxes.


  • Excellent Audio 3A Algorithm

    RTC uses technologies to perfectly reproduce your voice when you are singing, such as continuously evolved intelligent noise reduction and stable echo removal in multiple scenarios.

  • Dedicated Music Modes

    RTC prioritizes the quality of music and uses dedicated noise reduction algorithms to develop dedicated modes for music scenarios.

  • Ultra-low Latency

    RTC uses stable audio transmission technologies to offer low latency experiences.

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Online Board Gaming

RTC supports low-latency conversations in online board games, such as role-playing games. RTC can maintain high sound quality even in unstable network environments, ensuring the smoothness and stability of online board games and preventing players from being muted during the games.


  • Low-Latency Conversations

    RTC lowers the end-to-end latency to 250 milliseconds to ensure user experience in real-time conversations.

  • In-House ARWNT Algorithm

    RTC can resist a packet loss rate of up to 70% for audio data transmission and improve the transmission rate by 65% compared with counterparts in the same unstable network environment with the same packet loss rate.

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FM Broadcasting

RTC supports live audio broadcasts and allows listeners to interact with radio hosts using co-streaming. When you listen to the radio, you can enjoy high sound quality under background music.


  • Ultra-High Sound Quality

    RTC supports binaural stereo audio and a full-band audio sampling rate at 48 kHz. This ensures ultra-high sound quality.

  • Extensive Music Experience

    RTC supports special features, such as sound effects, background music, voice enhancements, voice changing, and reverb effects.

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One-to-One Online Teaching

RTC enables one-to-one online video teaching between a teacher and a student and supports cloud-based recording. This solution applies to scenarios, such as K-12 education, musical instrument training, and foreign language learning.


  • Stable and Reliable Network Services

    RTC provides comprehensive policies to handle unstable network connections and ensures the user experience in all network conditions with ultra-low latency of 250 milliseconds.

  • HD Image Quality

    RTC supports 1080p high definition (HD) image quality and real-time screen sharing to ensure face-to-face communication between teachers and students.

  • Real-Time Audio and Video Communication Services with Global Coverage

    Teachers and students in different cities and countries worldwide can access RTC services at any time.

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One-to-Many Small-Sized Classes

RTC allows a teacher to interact with 2-15 students at a time using online video teaching. Students can ask questions at any time during class. When the teacher stops lecturing, students can communicate and interact with each other. In addition, RTC supports features, such as screen sharing and audio and video recording. This solution applies to scenarios, such as K-12 education, foreign language learning, and musical teaching.


  • Real-Time Cloud-Based Recording

    The class can be recorded in real-time using cloud-based recordings, and students can watch the recorded videos after class.

  • Interactive Whiteboard Component

    An interactive whiteboard component is integrated to enhance the interaction between the teacher and students.

  • Adaptation to Thousands of Device Models

    Students can use different types of electronic devices to access the class with ease, including low-, middle-, and high-end PCs, mobile phones, and tablets.

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Super Small-Sized Classes

RTC allows a famous teacher to lecture students in more than 100 small-sized classes at the same time. Each class consists of 4-6 students. Students in the same class can communicate with each other using audio and video. Teaching assistants supervise the discipline during class and answer students' questions in real-time. This solution applies to scenarios featuring tutorials by famous teachers and parent experience classes.


  • Learning from Famous Teachers

    A famous teacher can lecture thousands of students at the same time. This allows students to learn from a famous teacher.

  • Real-Time Supervision by Teaching Assistants

    Teaching assistants can supervise the students in multiple classes and help students with their questions using co-streaming.

  • Cross-Channel Co-streaming

    The teacher, students, and teaching assistants can join multiple channels to interact with each other by using cross-channel co-streaming.

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Interactive Large-Sized Classes

RTC allows a teacher to lecture more than 10,000 students online. Students can interact with the teacher during class using co-streaming. This solution applies to scenarios, such as large-sized livestreaming classes, famous teachers' open classes, and vocational skill training.

  • Support for a Large Number of Viewers

    RTC ingests livestreams to a content delivery network (CDN) service provider for relayed livestreaming to ensure the online lecture can be watched by a large number of students.

  • Real-Time Interaction Using Co-Streaming

    Students can interact with the teacher during class using co-streaming.

Musical Training and Teaching

RTC enables music teachers to instruct students to play musical instruments using online video teaching. This solution applies to scenarios, such as musical instrument training and art test training.


  • High Sound Quality

    RTC supports binaural stereo audio and a full-band audio sampling rate at 48 kHz. This ensures ultra-high sound quality.

  • Excellent Noise Reduction Technology

    RTC provides the excellent audio 3A algorithm and noise reduction algorithms dedicated to music modes to ensure the perfect reproduction of music.

  • Musical Notation on a Whiteboard

    A whiteboard component is used to display musical notation and assist in musical instrument training.

Related Services

Co-Teaching with Two Teachers

RTC allows a famous teacher to interact with classes that reside in different regions and cooperate with teaching assistants in the classes to answer students' questions. This allows students in different regions to share a famous teacher. This solution applies to scenarios, such as postgraduate entrance examination teaching, civil service examination training, and offline co-teaching.


  • Combination of Software and Hardware

    RTC adapts to professional audio and video hardware and supports hardware coding to deliver a better performance.

  • Ultimate HD Experience

    RTC supports the encoding and decoding of 1080p ultra high definition videos to meet playback requirements on big screens in offline classrooms. This ensures a better visual experience.

  • Inputs from Multiple Video Sources

    RTC supports inputs from multiple video sources and switches between video sources.

Features of RTC

SDKs for Multiple Platforms

RTC provides device SDKs for multiple platforms, such as the web, Android, iOS, macOS, Windows, Linux, Unity, and mini programs, to be fully compatible with more than 6,000 mobile device models.

Voice Calls and Video Calls

After an SDK is integrated onto your device, you can make a voice call or video call to one or more people at a time.

Screen Sharing

You can share a window, the desktop, or a section with other users. This feature applies to scenarios, such as office collaboration, education and training, remote collaboration, and livestreaming for games.

Multimedia Features

An SDK provides features (such as sound effects, accompaniment music, in-ear monitoring, and local recording). You can also integrate different external multimedia components (such as external players, virtual background, and scene enhancement) to implement various interactive features (such as watching together, singing together, and virtual interaction).

Audio and Video Processing

RTC supports the input and output of raw data, small- and large-sized video streams, and supplemental enhancement information (SEI) transmission. Developers can integrate a wide range of custom audio and video interaction enhancements into device SDKs.

Media Effects

RTC supports a variety of audio effects such as voice beautification, voice changing, and reverb effects, and provides basic retouching and video filters free of charge. RTC also supports third-party retouching SDKs.

Recording and Playback

RTC allows you to record a single stream or mixed streams based on your business requirements. You can enable the audio or video recording feature by calling API operations or with simple configurations in the console. After streams are recorded, you can store the recorded content in your Object Storage Service (OSS) buckets. RTC provides an all-in-one on-demand video/audio streaming solution (in collaboration with ApsaraVideo VOD) that covers storage archiving, media editing, media resource management, automatic transcoding by using Narrowband HD™, video review and analysis, and delivery acceleration.

Relayed Livestreaming

You can ingest a single stream without transcoding or ingest mixed streams with transcoding based on the actual scenario. After RTC ingests live streams to ApsaraVideo Live in compliance with standard live streaming protocols, viewers can use CDN services to watch the streams.

Monitoring Dashboard

RTC collects and analyzes large amounts of audio and video quality data to monitor audio and video quality from multiple dimensions at multiple levels. You can use the Quality Monitor module of the console to implement features such as communication monitoring, usage statistics, exception diagnostics, and quality statistics.

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