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Ably vs Google Cloud Pub/Sub

Let us help you discover why Ably is clearly the better choice.

Easily build complete, trusted realtime functionality.

Take our APIs for a spin
Why it matters?
Global datacenters locations 7 56 zones

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.

Google Cloud Pub/Sub can rely on Google’s existing datacenters across the globe in the Americas, Asia and Europe.

Find out more about Ably's datacenters
Latency based routing

Our latency based routing ensures that users anywhere in the world connect through one of our 635 edge acceleration PoPs to one of our 7 Ably datacenters.

When a client connects to Google Cloud Pub/Sub the router will connect to the datacenter with the shortest network distance.

Find out more about Ably's latency based DNS
Binary encoded messages Limited

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.

Google Cloud Pub/Sub allow for binary encoding only over gRPC and protobuff.

Find out more about our binary protocol
Redundancy and Reliability
Mesh architecture / no central point of failure / self-healing cluster

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.

Google Cloud Pub/Sub use routing constraints to move traffic away from datacenters that are not functioning as expected.

Find out more about Ably's mesh architecture
Autonomous datacenters

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.

Google Cloud Pub/Sub operates servers located in 56 datacenters across 4 continents which can operate as part of a global cluster or autonomously when necessary.

Find out where Ably's servers are located
Data replicated in multiple regions

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.

Find out about Ably's QoS and message delivery guarantee
QoS & message delivery guarantee

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 Google Cloud Pub/Sub, a published message is stored in the Google Cloud service until the client reconnects, and confirms it has received the message with an ACK.

Find out about Ably's message delivery guarantee
Uptime SLA guarantees

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

Google Cloud Pub/Sub only offer a SLA up to 99.95% uptime.

Find out about Ably's uptime guarantees
Message and worker queues

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

Google Cloud Pub/Sub also supports this feature.

Find out more about Ably Queues

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

Both Ably and Google Cloud Pub/Sub support the use of Webhooks.

Find out more about Webhooks
Serverless cloud function invocation Limited

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

Google Cloud Pub/Sub only offer server-less functions on their own Google function thus limiting the choices available to you.

Find out more about Webhooks

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.

Google Cloud Pub/Sub does not support Presence, you can only check who is subscribed, not their status in an automated fashion.

Find out more about Presence
Message history Limited

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

Google Cloud Pub/Sub only allows you to obtain your subscription history if you’ve not yet ACK’d. Once you have retrieved your messages, you can no longer retrieve them again. Snapshots are a method that Google Cloud Pub/Sub use to remember certain parts of communication however.

Find out more about our History API
Realtime data firehose

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

Find out more about our Firehose
Reliable message ordering

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

Google Cloud Pub/Sub does not guarantee first order and instead publishes messages as fast as possible. This could cause issues with messages being received by subscribers in the wrong order; an issue that would not occur using Ably.

Find out more about reliable ordering
Push notifications

Ably supports Push notifications, whilst Google Pub/Sub does not innately support it.

Find out more about Push Notifications
Custom domain endpoint (CNAME)

Ably supports custom domains for our Enterprise customers allowing them to connect to Ably using a CNAME such as "".

Google Cloud Pub/Sub does not support the use of CNAME.

Find out more about our custom domains
Client libraries and protocol support
Native client libraries for every popular platform

Ably offer a considerable range of client libraries for every popular platform.

Google Cloud Pub/Sub has few libraries for client platforms, mainly focusing on server platforms.

View our client library SDKs
Continuity and connection state recovery

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.

Find out more about connection state recovery
1st class WebSocket support

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

Google Cloud relies primarily on gRPC.

View our supported transports
Fallback to Comet (XHR) and Long Polling for older browsers

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

Google Cloud Pub/Sub has HTTP as a secondary option to gRPC.

View our supported transports
TLS connection

Ably and Google Cloud Pub/Sub offer TLS connections ensuring that all data in transit is encrypted.

Find out more about SSL/TLS
Token based authentication

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

Ably allows configurable policies and an identity 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.

Google Cloud Pub/Sub only support the verification of messages from their servers using token authentication.

Find out more about Ably's authentication
Configurable private key permissions

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

Google Cloud Pub/Sub does not support configurable private key permissions.

Find out more about API keys
Configurable channel permissions

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.

Google Cloud Pub/Sub does not support configurable channel permissions.

Find out more about channel rules
Encrypted message payloads

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.

Google Cloud Pub/Sub does not provide encrypted message payloads in their client libraries.

Find out more about Ably's encryption

* All information regarding our competitors was obtained on or before May 2018. It is therefore possible that some of this information may now be out of date. If you believe that any of this information is incorrect, please get in touch with us so that we can correct it immediately.

Migrating to Ably

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