Deep Technical Comparison: CometChat vs Stream Chat

CometChat is primarily offered as a SaaS platform and does not provide an official self-hosted version. All backend infrastructure and data storage are managed by CometChat’s cloud services. Teams requiring full self-hosting for compliance or data control purposes will need to consider alternative solutions or contact CometChat for enterprise options that might offer more control.

CometChat supports offline messaging by queuing messages on the server when recipients are offline and delivering them once they reconnect. The SDK provides local caching to ensure messages are available in the app even without a live connection, but full synchronization depends on the client reconnecting to the CometChat cloud backend. There is no built-in peer-to-peer offline mode.

Chat data stored in CometChat is owned by the customer using the service. CometChat provides APIs and dashboard tools to export chat histories and user data in standard formats. However, exporting large datasets may require use of their premium plans or contacting support for bulk export assistance. Data retention policies are configurable within plan limits.

CometChat enforces API rate limits based on the subscription tier to ensure service stability. Free and lower-tier plans have stricter limits on message throughput and concurrent connections, which can impact high-scale applications. The SDK supports all core messaging features, but some advanced capabilities like message translation or moderation require higher-tier plans. Detailed API limits are documented in their developer portal.

CometChat does not provide an automated migration tool, so teams typically export chat data from their existing platform and import it into CometChat using their REST APIs or SDKs. This process requires custom scripting to map user IDs, message formats, and metadata. Planning for downtime and data consistency is critical, and CometChat support can assist with best practices during migration.

Stream Chat is a fully managed SaaS product and does not offer a self-hosted version. All chat infrastructure, scaling, and maintenance are handled by Stream's cloud service. This means you cannot run the backend on your own servers, but you do get a scalable and reliable service without operational overhead.

Stream Chat SDKs provide offline support by caching messages locally and syncing with the server once the device reconnects. Messages sent while offline are queued and delivered automatically. However, real-time presence and typing indicators require connectivity. The SDKs handle conflict resolution and maintain message order upon reconnection.

All chat data stored in Stream Chat belongs to the customer using the service. Stream provides APIs to export message history and user data, but there is no built-in bulk export tool. Customers typically implement their own data export scripts using the REST API. Data retention and deletion policies can be configured per account.

Yes, Stream Chat enforces API rate limits based on your subscription plan to ensure fair usage and performance. Typical limits include requests per second per user and message size capped at 4KB per message payload. Exceeding limits results in HTTP 429 errors. Higher-tier plans offer increased limits and throughput.

Stream Chat does not provide a native migration tool, but you can import historical chat data by using their REST API to programmatically create channels and messages. This requires writing a custom migration script that respects Stream's data model and rate limits. Planning for user ID mapping and message timestamps is essential.