Ably vs Realtime.co

As we have datacenters globally, we can ensure that your users always experience the lowest possible latency by connecting to the closest datacenter, and have complete availability by connecting to alternative healthy datacenters when necessary.

Realtime.co approximately 3-6 datacenters spread across three geographical locations, Europe, US East and US West. Customers that are not close to those datacenters may experience some latency.

Both Ably and Realtime.co offer latency based routing that ensures users anywhere in the world connect to the closest datacenter available to them.

Encoding messages in binary format is faster. It reduces bandwidth to send and receive messages, and streamlines the processing time for clients and servers when encoding and decoding messages.

Realtime.co does not support binary encoded messages.

The Ably platform is designed with no single point of failure and to be self-healing. All our customers benefit from their apps running on all of our datacenters providing resilience, reliability and low latencies globally.

Ably's servers are located in 7 datacenters covering 4 continents with each datacenter designed to operate as part of the global cluster when available, but operate autonomously when necessary.

Ably stores every message in at least two datacenters and separate geographical regions. This ensures that an outage in any datacenter or region cannot result in data loss.

Realtime.co does not persist messages so any message lost in transit is never recovered.

Ably provides guaranteed message delivery and continuity across disconnections. Publishers only receive an ACK when data is persisted in two locations, and subscribers never lose data during brief disconnections as we maintain connection state for each client on our servers.

With Realtime.co, if a message is published whilst a client is briefly disconnected (such as going through a tunnel or changing networks), then the message will never arrive to that client.

Ably offers varying levels of uptime guarantees depending on your needs. For all of our enterprise customers we provide a 99.999% uptime SLA.

Realtime.co offer an SLA only for corporate customers on custom packages.

Data published into Ably's realtime system can be moved into traditional message queues for realtime or batch processing.

Realtime.co does not offer message queuing features or a means to distribute data using once-only pattern to your server workers.

Ably's Webhooks provide a means to get messages, channel lifecycle and present events pushed to your servers over HTTP. Both Ably and Realtime.co support Webhooks.

Ably can trigger serverless functions on any third platforms such as Amazon Lambda, Microsoft Azure or Google Function.

Realtime.co recommends the use of a generic Webhook to be delivered to an API Gateway that in turn triggers a function.

Presence allows you to subscribe to events when users or devices enter or leave channels. This is a useful feature for collaborative apps, games and chat rooms.

Realtime.co supports a maximum of 100 members per channel. Ably supports 200 by default and far more upon request.

Ably's message history feature provides a means for clients or servers to retrieve messages that were previously published on a channel.

Realtime.co does not support message history.

Stream your realtime data published within the Ably platform directly to another streaming or queueing service such as Amazon Kinesis, Apache Storm or Kafka.

Ably ensures that messages are delivered to persistently connected subscribers in the order they were published on each channel.

Realtime.co does not provide these guarantees.

Both Realtime.co and Ably offer push notifications.

Data published into Ably's realtime system can be moved into traditional message queues for realtime or batch processing.

Realtime.co does not offer any message queuing features or ways to distribute data using once-only pattern to your server workers.

Ably supports custom domains for our Enterprise customers allowing them to connect to Ably using a CNAME such as "realtime.your-company.com".

Realtime.co does not provide support for custom CNAME endpoints.

Both Ably and Realtime.co offer a considerable range of client libraries for every popular platform.

Using our protocol adapters, our customers can use the large selection of PubNub embedded client libraries for low energy and other embedded devices.

Realtime.co has a small set of client libraries suitable for embedded devices.

The Ably platform is designed to be protocol-agnostic and ensure protocol interoperability. Ably supports MQTT./p>

Realtime.co does not support MQTT.

The Ably platform is designed to be protocol-agnostic and ensure protocol interoperability. That's why we support SSE. Realtime.co does not support SSE.

Ably provides continuity for clients that become disconnected for reasons such as going through a tunnel or changing networks. Ably stores the connection state for each client on its servers so that clients that reconnect within two minutes can resume their connection and receive all messages published whilst they were disconnected.

With Realtime.co, if a message is published whilst a client is not connected, then the message is effectively lost and will never be delivered to that client. Realtime.co expects the developer to handle data loss due to loss of connectivity.

WebSockets are widely regarded as the most efficient HTTP compatible transport for full duplex realtime communication between devices.

Whilst most modern devices support WebSockets, there are situations where the device or the network environment requires use of HTTP transports.

Both Ably and Realtime.co offer TLS connections ensuring that all data in transit is encrypted.

Token based authentication ensures your private key is never shared and instead a short-lived token is used to authenticate.

Ably and Realtime.co allow configurable policies to be embedded in a token ensuring you have complete control over what actions your users can perform such as limiting which channels they can subscribe or publish to.

Using JWT allows for easy integration with your existing authentication systems, along with ensuring your private key is never shared.

Ably allows for not only Ably Tokens to be embedded within JWTs, but also for JWTs to be signed by Ably API keys and used themselves for authentication.

Realtime does not support JWT.

Ably provides support for private API keys with configurable permissions including restrictions on channels or operations.

Realtime.co does not support configurable permissions for keys.

Ably provides channel rules providing you with the flexibility to maintain control of your channels, such as requiring SSL/TLS or only identified authenticated clients on a channel.

Realtime.co does not provide channel configuration rules.

Ably's AES encryption allows messages to be encrypted using the provided private key before they are published to Ably. As a result, messages are practically impossible to intercept and view for anyone including Ably. For very sensitive data, this ensures you can safely use us knowing your payloads are always secure and opaque.

Realtime.co does not provide payload encryption in their client libraries.