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Pusher vs Socket.IO

Discover how Pusher compares to Socket.IO, and understand which is right for your use case, based on dimensions such as core features, pricing, reliability, and scalability.

What is Pusher?

Pusher is a first-generation pub/sub messaging service that provides bi-directional hosted APIs for adding realtime features to applications. Pusher offers two products: - Channels - Build scalable realtime features - Beams - Programmatic push notifications

Suitable for:

  • Realtime charts
  • Location tracking
  • Notifications
  • In-app chat

Not suitable for:

  • Audio and video

Pros:

  • Great developer experience

Cons:

  • Not reliable at scale or spikes
  • Must choose one data center to locate apps
  • Bigger message latencies for clients further away from data center
  • No message delivery guarantees

What is Socket.IO?

Socket.IO is a library created in 2010 that provides realtime, bi-directional communication between clients and servers. It allows the management of connections, sending and receiving messages, and more. Built on top of the WebSocket protocol, it provides additional capabilities compared to raw WebSockets. WebTransport (a WebSocket alternative) is also supported.

Suitable for:

  • Chat and messaging
  • Dashboards
  • Mulitplayer games

Not suitable for:

  • Audio & video

Pros:

  • Multiplexing and data broadcast support
  • Disconnection detection and automatic reconnections
  • Adapters for horizontal scaling
  • Fallback support

Cons:

  • Message ordering guarantees are at most once / least once only
  • Memory leakage issues
  • Not multi-region

Compare Pusher and Socket.IO

Let’s compare Pusher and Socket.IO, looking at key dimensions such as their core features, pricing, integrations, QoS, performance, and security and compliance.

Disclaimer:This comparison was created based on documentation and resources freely available online about Pusher and Socket.IO. The content was last updated on 10 Jun 2024 for Pusher and on 10 Jun 2024 for Socket.IO. Be sure to double-check everything before you make any decisions. If you do find anything incorrect or out of date, then please contact us.

Core features
Pub/Sub messaging

Reduces communication code complexity, simplifying the process of building highly functional and architecturally complex realtime apps.

Pusher

Yes

Socket.IO

No

Need to rely on a third party - e.g. use a Redis adapter to broadcast events to clients through the Redis pub/sub mechanism.

Read more
Chat capabilities

Accelerates the time to implement rich chat experiences with features such as read receipts, typing indicators, and more.

Pusher

No

Pusher has channels which enable read receipts, but no SDK, reactions, or read-receipts built in.

Read more
Socket.IO

Partial

As it's a library, you need to create the chat capabilities yourself. But this can be done using Socket.IO.

Collaboration capabilities

Enables you to quickly integrate realtime collaborative features like live cursors, member location, avatar stacks, and component locking.

Pusher

No

Socket.IO

Partial

As it's a library, you need to implement collaboration capabilities yourself. But you can do this using Socket.IO itself.

State sync capabilities

Enables realtime data synchronization across devices and users, ensuring a cohesive and up-to-date user experience.

Pusher

No

Pusher has 'cache channels', but this is just persist-last.

Read more
Socket.IO

No

The library does not support this. You would need to create a bespoke state sync capability or integrate a third party library to get state synchronisation.

Presence

Maintaining a view of which users are connected, and their associated metadata, enables their online status to be updated in realtime.

Pusher

Yes

Socket.IO

Partial

It is the duty of your application to link a Socket.IO connection to a user account.

Read more
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.

Pusher

No

Socket.IO

Partial

Rooms are available. It is possible to query for rooms and SIDs.

See more
Message interactions

Enables interaction with previously-sent messages, facilitating the implementation of features like message reactions and threads.

Pusher

No

Socket.IO

Partial

You would need to build the message interaction functionality yourself on top of Socket.IO.

Learn more
Message history

Enables clients to catch up on missed messages when inactive, ensuring a user doesn’t miss any important messages.

Pusher

No

Pusher does not offer any message history functionality. But Cache Channels stores the last event sent to the channel - it is stored for a max of 30 min or until a new event arrives. This can be useful in some use cases.

Socket.IO

No

The Socket.IO server does not store messages. Your application has to persist messages somewhere for the clients that are not currently connected.

Learn more
Push notifications

Cross-platform push notifications make it possible to deliver important and timely messages to users even when they’re inactive.

Pusher

Yes

Pusher's product Beams is a cross-platform push notifications API.

Socket.IO

No

Socket.IO not support Push notifications. You would need to build this capability yourself and/or use another library.

Learn more
Message delta compression

Minimizes bandwidth and can reduce latency, particularly in scenarios where continuous updates are sent.

Pusher

No

Socket.IO

No

Programmatic management

Enables the automation of provisioning, management, and testing of service resources, simplifying integration with existing development workflows such as CI.

Pusher

No

Socket.IO

Yes

The Socket.IO server is initialised in code. It is possible to configure the socket.IO server's configuration in code as well.

Learn more
Pricing
Free plan

With a free plan, you can test the service’s functionality and compatibility with your project before committing to a paid plan.

Pusher

Partial

Only in 'sandbox', which is a free plan which gives you 200,000 messages and up to 100 concurrent connections per day.

Socket.IO

Yes

Open Source framework that uses the MIT license.

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.

Pusher

Free, Flexible pricing plans and Enterprise

See more information
Socket.IO

Open Source framework that uses the MIT license.

Integrations & interoperability
SDKs

Supporting multiple languages and platforms offers greater flexibility when building cross-platform realtime apps.

Pusher
  • Android (uses Java library)
  • AngularJS (uses JavaScript library)
  • iOS: Swift and Objective-C
  • Java
  • JavaScript
  • .NET
  • Unity
  • Flutter
  • React Native
Socket.IO

Client and Server APIs only.

  • C++
  • Swift
  • Java
  • Javascript
  • Typescript
  • Node.js
  • Python
  • Golang
  • Rust
  • Dart
  • .NET
  • Kotlin
Supported realtime protocols

Support for multiple protocols provides the flexibility to choose a protocol that best suits your project’s requirements.

Pusher
  • WebSockets
  • Fallback to Comet (XHR) and Long Polling for older browsers
Socket.IO
  • WebSocket
  • WebTransport
  • HTTP
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.

Pusher
  • Own serverless functions
Socket.IO

No

It is not possible to trigger serverless functions with Socket.IO on it's own.

See this Reddit post for more info
Streaming & queueing

Provides a dependable method to reroute messages from the service to third-party streams and queues for further processing.

Pusher

No

Socket.IO

No

Socket.IO does not offer native queues and streaming.

Observability services

Enables realtime monitoring and troubleshooting by offering insights into service behavior directly in your observability platform of choice.

Pusher

Yes

Pusher provides Datadog and Librato integrations.

Socket.IO

Yes

The Socket.IO admin UI can be used to have an overview of the state of your Socket.IO deployment.

CI/CD tools

Makes it possible to provision and configure service infrastructure as part of a CI or CD pipeline, enabling repeatable and reliable deployments.

Pusher

No

Socket.IO

No

Quality of Service
Scalability

Scalability is vital as it ensures the service can handle increased data load or users without compromising performance.

Pusher

No scalability metrics published.

Socket.IO

No published metrics. Socket.IO servers don’t communicate between them, so you need a way to route events to all clients, even if they are connected to different servers. This is made possible by using adapters, of which the Redis adapter seems to be the most popular choice.

Guaranteed message delivery

Ensures messages are never lost during transmission, even in the presence of network disruptions.

Pusher

No

Socket.IO

Partial

By default, Socket.IO provides an "at most once" guarantee of delivery. From the client side, you can achieve an at least once guarantee with acknowledgements and timeouts.

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.

Pusher

No

Socket.IO

Yes

Socket.IO guarantees ordering, no matter which low-level transport is used.

Read more
Exactly-once message delivery

Guarantees that each message is processed exactly once, preventing data inconsistencies that can arise from duplicate processing or missing messages.

Pusher

No

Socket.IO

No

At least once or at most once only.

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.

Pusher

Channels SLA: API will be made available with an Annual API Uptime Percentage of 99.95%.

Pusher will use commercially reasonable efforts to make Pusher Beams available with an Annual Uptime Percentage of > 99.95%.

Read more
Socket.IO

No

It is a library, not a platform.

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.

Pusher

No

Socket.IO

No

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.

Pusher

No

Pusher apps are located in a single data center rather than distributed across multiple data centers. Any latency issues that occur in that data center will affect all apps hosted there.

Socket.IO

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.

Pusher

No

Pusher apps are located in a single data center rather than distributed across multiple data centers. If that data center goes offline then all apps hosted there are affected.

Socket.IO

No

As Socket.IO is a library, the implementation of it dictates points 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.

Pusher

Not shared. Because apps exist in only one region, message latencies increase for clients the further they are from your chosen data center.

Socket.IO

Unknown

Security & compliance
API key authentication

Simplifies the authentication code on trusted servers compared to requesting, managing, and refreshing tokens.

Pusher

Yes

Socket.IO

No

Token-based authentication

Provides a means to securely authenticate user devices against your user management system.

Pusher

Yes

Socket.IO

No

No native Token based auth. It is possible to use middlewares.

Single Sign-On (SSO) authentication

SSO streamlines login processes, boosts security by minimizing password use, and meets compliance needs for secure data access management.

Pusher

Partial

For GitHub and Google.

Socket.IO

No

No native SSO. It is possible to use middlewares.

Rules for permissions and operations

Provides control over which users can subscribe and publish to certain channels.

Pusher

Partial

Requires you to implement an endpoint they will call to check if operation is allowed.

Socket.IO

No

End-to-end encryption

Ensures that the data transmitted between the client and the API server remains confidential and secure while in transit.

Pusher

Yes

Socket.IO

No

Encryption at rest

Ensures data stored by the service is secure and compliant, while also mitigating the risks of a data breach.

Pusher

No

Socket.IO

No

Compliance

Compliance with regulations can impact your ability to meet legal obligations in your industry.

Pusher

EU GDPR compliant

Socket.IO

None.

Alternatives to Pusher and Socket.IO

Whilst both Pusher and Socket.IO are worth considering as options for realtime experiences, they aren’t without their limitations. We suggest evaluating them against the following alternatives to make sure you find the right solution for your needs.

Alternatives to Pusher

PubNub is a developer API platform that powers the realtime infrastructure in apps to build engaging Virtual Spaces where online communities can connect.

Socket.IO is a library that provides realtime, bi-directional communication between clients and servers. It allows the management of connections, sending and receiving messages, and more.

Ably is the definitive realtime experience platform of the internet. Serving more WebSocket connections than any other pub/sub platform on earth. Businesses trust us to power their critical applications - reliably, securely and at serious scale.

Alternatives to Socket.IO

Azure-hosted, fully managed realtime framework built on top of an open-source software library for Microsoft ASP.NET.

PubNub is a developer API platform that powers the realtime infrastructure in apps to build engaging Virtual Spaces where online communities can connect.

Pusher is a first-generation pub/sub messaging service that provides bi-directional hosted APIs for adding realtime features to applications.

Discover how Pusher and Socket.IO stack up against Ably

Ably is the definitive realtime experience platform of the internet. See how we compare to Pusher and Socket.IO on key dimensions such as core features, pricing, integrations, QoS, performance, and security and compliance.

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