Ably vs Stream
Discover how Stream compares to Ably, and understand which is right for your use case, based on dimensions such as scalability, pricing, security, and their chat features.
What is Ably?
Ably is a realtime experience platform that provides APIs and SDKs to power realtime functionality - with no realtime infrastructure to build and maintain. Our application building blocks and integrations enable developers to quickly create live experiences from live chat and data broadcast, to collaborative UXs and notifications.
What is Stream?
Stream is a platform for building scalable, realtime chat and activity feed applications. It provides APIs and SDKs to easily integrate messaging, video calls, and social feeds into apps.
Compare Ably and Stream
Let’s compare Ably and Stream, looking at key elements of their offering such as their scalability, pricing, security and chat feature set.
| Scalability | |||
Concurrent connections | Number of users that can be supported in a single chat. | Ably | Stream 2500 users supported in a single chat. Supported within Start and Elevate packages. Overages apply if you exceed plan quota - $0.79 per additional concurrent user. Read more |
Connections | Number of connections that can be handled across the platform. | Ably | Stream |
Channels / rooms | Number of channels or rooms that can be handled across the platform. | Ably | Stream Unlimited. |
Messages | Number of messages that can be handled across the platform. | Ably Unlimited. See pricing for details | Stream Unlimited. |
Message throughput | Number of messsages that can be published per second. | Ably From:
| Stream 5 messages per second. When concurrent connections exceeds 100 in a group messages are throttled to 5 per second. |
| Data integrity | |||
Guaranteed message delivery | Ensures messages are never lost during transmission, even in the presence of network disruptions. | Ably Yes | Stream No |
Guaranteed message ordering | Maintains the sequence of messages as they were sent. This is particularly important in apps where the chronological order of messages is essential for meaningful communication. | Ably Yes | Stream No |
Exactly-once message delivery | Guarantees that each message is processed exactly once, preventing data inconsistencies that can arise from duplicate processing or missing messages. | Ably Yes | Stream No |
| Performance & availability | |||
Uptime Guarantee | An uptime guarantee instills confidence in the reliability of the service and protects your business from the negative impacts of downtime. | Ably 99.999% | Stream
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Global edge network | By bringing servers (Points of Presence, or PoP) geographically closer to the devices of end users, and routing requests to the nearest PoP, global latency is reduced to a minimum. | Ably Yes All Ably customer data runs across all our 7 geographically-distributed core routing datacenters by default. Ably's network of 385 edge acceleration points-of-presence is growing day by day. | Stream Yes Stream has data centers located around the world, including:
|
Multi-region data replication (message durability) | By replicating data across multiple regions, the risk of data loss or downtime is greatly mitigated since if data is lost or a server fails in one region, the information can be retrieved from another. | Ably Yes | Stream No |
No single point of failure or congestion | Having no single point of failure means a system is resilient and can continue to operate even if one part fails. Avoiding a single point of congestion ensures messages flow efficiently across the system and avoids bottlenecks that could lead to performance issues under load. | Ably Yes | Stream Yes Stream's chat infrastructure does not rely on a single data center due to global edge network support, thus avoiding a single point of failure and congestion. |
Latency | Low latency is crucial for realtime apps as it ensures swift and efficient data transmissions, providing a smoother and more responsive user experience. | Ably <50ms round trip latency for the 99th percentile; <35ms latency once traffic arrives within AWS | Stream Stream does not provide a global latency figure. However, it achieves a region-based average roundtrip latency of 170 ms between Amsterdam and the US East. |
Server-side batching | Reduces the overall message count, lowers costs, and mitigates the risk of hitting rate limits during high-throughput scenarios. | Ably Yes | Stream |
Connection state recovery | Automatically re-establish failed connections and replay missed messages. | Ably Yes | Stream Yes Stream SDKs automatically attempt to recover the connection and ensure that a connection to Stream chat is always kept alive. That chat state is recovered when the user's internet connection comes back online. |
| Ecosystem support | |||
Supported realtime protocols | Support for multiple protocols provides the flexibility to choose a protocol that best suits your project’s requirements. | Ably
| Stream WebSocket. |
Supported languages | Supporting multiple languages and platforms offers greater flexibility when building cross-platform realtime apps. | Ably
| Stream
|
| Chat room types | |||
Multi-type chat support (group, DM, supergroups) | Enables chat experiences to be tailored to various user needs, from one-on-one to large, scalable group discussions. | Ably
| Stream Stream provides the following chat room types:
|
| Chat room management | |||
Presence | Maintaining a view of which users are connected, and their associated metadata, enables their online status to be updated in realtime. | Ably Yes | Stream Yes |
Occupancy | High-level metrics about the clients currently connected to a channel make it simple to show things such as connected user count, or display which channels are the most popular. | Ably Yes | Stream No |
Typing indicators | Show when others are typing in a chat room, enhancing realtime communication flow. | Ably Yes Ably Chat provides typing indicators to show when users are composing messages. | Stream Yes Stream supports typing indicators, which appear on the channel list item where someone is typing or in the chat channel view. |
Room reactions | Customize the chat environment with reactions and other shared room states. | Ably Yes Ably Chat supports room-level reactions with a variety of emojis. Ephemeral reactions are not counted or aggregated. | Stream No |
| Chat message attributes | |||
Message edits and deletes | Allow users to modify or remove messages. | Ably Yes Ably Chat supports soft deletion of messages and message edits. | Stream Yes |
Message reactions & emoticons | Boost engagement by enabling users to quickly express emotions or feedback on messages. | Ably Yes Ably Chat supports reactions at the room level and message level. | Stream Yes |
Rich text support | Enhance messages with rich text formatting in chat. | Ably Yes | Stream Yes Stream SDKs offer markdown formatting for channel messages. |
Media attachments | Support for sharing images, videos, and files in chat. | Ably Partial Links are supported. | Stream Yes |
| Chat application and user state | |||
In-app notifications | Notify users of important events from other chat rooms without them leaving the current chat, keeping them engaged and informed. | Ably Yes In-app notifications supported via Ably Pub/Sub. | Stream Partial Stream only supports in-app notification feeds. |
Role-based permissions | Control user roles and permissions to ensure proper access and moderation. | Ably No Ably Chat doesn't current support role-based permissions, but will soon. | Stream Yes |
UI kit | Customizable UI elements for a seamless chat integration. | Ably No Ably Chat doesn't currently offer a UI kit. | Stream Yes Stream offers UI kits for social media design and chat interfaces. |
| Storage and history | |||
Synchronous - automated moderation | Detect and manage harmful content automatically, before the message is broadcast to participants. | Ably Yes Ably Chat supports synchronous moderation using Hive AI. You can also integrate with a third-party moderation provider. | Stream Yes |
Asynchronous - automated moderation | Detect and manage harmful content automatically, after the message is broadcast to participants. | Ably Yes Ably Chat supports asynchronous moderation using Hive AI. You can also integrate with a third-party moderation provider. | Stream |
Manual moderation via dashboards | Tools for moderators to detect harmful messages and manage them effectively. | Ably Yes Ably Chat supports manual moderation through Hive Dashboard. | Stream Yes Stream offers manual moderation capabilities through its Chat Dashboard, which allows you to do standard moderation tasks. Read more |
Ban users | Remove problematic users from the chat to maintain a healthy environment. | Ably Partial Ably Chat doesn't support banning users outright, but you can approximate user banning by revoking user access tokens. | Stream Yes |
| Dev tools | |||
Programmatic management | Enables the automation of provisioning, management, and testing of service resources, simplifying integration with existing development workflows such as CI. | Ably Yes | Stream Yes |
| Pricing | |||
Pricing model | The pricing model should align with your project's expected load, usage patterns, and budget in order to be cost-effective and efficient. | Ably Ably offers a per-minute, consumption-based pricing model. This gives granular control over your costs, eliminating the need to pay for peak users or connections. | Stream Stream's pricing plan is based on MAUs. Overages apply for additional MAU's and peak concurrent connection - over set quota. Read more |
Pricing illustration | An example price based on 5 live streaming chat events and 50K attendees. | Ably $1029.95 Cost of messages = $1026.95 Cost of connection minutes = $2.00 Cost of channels = $1 Explore the pricing estimator tool | Stream $22,186.50.
Note: Assumes same users attend each event, to keep MAU at minimum. |
Free plan | With a free plan, you can test the service’s functionality and compatibility with your project before committing to a paid plan. | Ably Yes | Stream Yes Offers:
|
Pricing plans | The pricing plans offered by cost. | Ably The free and paid plans are:
| Stream
Overages:
|
| Support for additional realtime features | |||
Pub/Sub messaging | Reduces communication code complexity, simplifying the process of building highly functional and architecturally complex realtime apps. | Ably Yes Ably provides robust pub/sub messaging capabilities over serverless WebSockets. | Stream No |
Collaboration capabilities | Enables you to quickly integrate realtime collaborative features like live cursors, member location, avatar stacks, and component locking. | Ably Yes The Spaces SDK provides an opinionated set of abstractions for collaborative environments including live cursors, avatar stacks and component locking. Learn more | Stream No |
Database sync capabilities | Database sync capabilities enable realtime updates between your database and UI, ensuring the UI reflects changes in the database instantly, with data consistency, and without the need for polling. | Ably Yes Ably provides a self-hostable and managed database connector to stream updates over our serverless WebSocket platform. Ably also provides the Models SDK for seamless connector interactions. Learn more | Stream No |
Notifications | Send notifications directly to users screens, from chat responses to news alerts, or game updates, whether or not an application is open and running. | Ably Yes Support for Android and iOS push notifications. Improved web push for browsers currently in progress. | Stream Yes |
Asset tracking | State-of-the-art asset tracking across last mile logistics, food delivery applications, and urban mobility services. | Ably Yes | Stream No |
| Integrations & interoperability | |||
AI models | Allows you to integrate AI models, like GPT, into your app. | Ably Yes Ably Chat supports the integration of AI models for automatic sync moderation. | Stream Yes Stream supports integration with AI models from OpenAI, HuggingFace, Claude, or any LLM for its chat and voice AI SDKs. |
Serverless functions | Enables integration with third-party cloud providers by facilitating the execution of custom code against messages to perform business logic like on-the-fly translation. | Ably
| Stream No |
Streaming & queueing | Provides a dependable method to reroute messages from the service to third-party streams and queues for further processing. | Ably Egress:
Ingress:
The Database Connector is designed for any database in the SQL-family, but at the moment only supports Postgres. Please contact us if you want support in other databases. | Stream No |
Observability services | Enables realtime monitoring and troubleshooting by offering insights into service behavior directly in your observability platform of choice. | Ably Yes | Stream No |
| Security & compliance | |||
API key authentication | Simplifies the authentication code on trusted servers compared to requesting, managing, and refreshing tokens. | Ably Yes | Stream Yes Stream uses API keys for authentication. You must include an API key when sending an authenticated request to Stream. |
Single Sign-On (SSO) authentication | SSO streamlines login processes, boosts security by minimizing password use, and meets compliance needs for secure data access management. | Ably Yes | Stream Yes Stream offers Single Sign-On (SSO) authentication through GitHub Organizations and SAML 2.0. The SSO is available to organizations on Stream's Enterprise Chat or Feeds plan. Read more |
Rules for permissions and operations | Provides control over which users can subscribe and publish to certain channels. | Ably Yes | Stream Yes Stream applications offer customizable built-in roles. Users receive a role with permissions for the whole app and can also have channel-specific roles for single or multiple channels of the same type. |
End-to-end encryption | Ensures that the data transmitted between the client and the API server remains confidential and secure while in transit. | Ably Yes Ably offers SSL/TLS encryption and 256-bit AES encryption using private keys. Message payloads can only be decrypted by other clients that share your secret key. Learn more about Ably's encryption | Stream No Stream does not natively implement E2EE. It encrypts messages in transit using TLS 1.2 and at rest with AES256. Read more |
Compliance | Compliance with regulations can impact your ability to meet legal obligations in your industry. | Ably
Ably also offers EU and US-only data storage. | Stream Stream is compliant with five standards and regulations to ensure the security and privacy of its users' data:
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Disclaimer: This comparison was created based on documentation and resources freely available online about Ably and Stream. The content was last updated on 30 Apr 2025 for Ably and on 1 May 2025 for Stream. Be sure to double-check everything before you make any decisions. If you do find anything incorrect or out of date, then please let us know.
Hear from companies gaining their realtime advantage with AblyThe core infrastructure for delivering live sports data to our customers is Ably. We sleep easier at night knowing it can be relied on for consistent low latency and message integrity at scale.”
Gary Williams
IT Infrastructure Team Lead
Ably immediately solved our issues around the user experience and scale. It supports our customers’ stringent expectations as well as future product development.”
Max Freiert
Product Group Lead
Ably copes easily with big loads. We don’t have to worry about stability, even when we get huge traffic spikes.”
Johan Bengtsson
CTO
Try Ably for free to discover the benefits for yourself
Ably has built reliable realtime infrastructure so you don’t have to. On our free plan you benefit from:
- 6M monthly messages
- 200 concurrent channels
- 200 concurrent connections
