Ably vs PubNub

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

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 PubNub?

PubNub is a developer API platform that powers the realtime infrastructure in apps to build engaging Virtual Spaces where online communities can connect. It can serve as the foundation for online chat, live events, geolocation, remote IoT control, and realtime updates.

Compare Ably and PubNub

Let’s compare Ably and PubNub, looking at key dimensions such as their core features, pricing, integrations & interoperability, quality of service, performance & availability and security & compliance.

Disclaimer: This comparison was created based on documentation and resources freely available online about Ably and PubNub. The content was last updated on 30 Apr 2025 for Ably and on 30 Apr 2025 for PubNub. 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 If you do find anything incorrect or out of date, then please let us know.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 Ably

“

The 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

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“

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

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“

Ably copes easily with big loads. We don’t have to worry about stability, even when we get huge traffic spikes.”

Johan Bengtsson

CTO

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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

Get started for free Read our docs

	Ably	PubNub	Why this matters
Core 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.	PubNub Yes	Reduces communication code complexity, simplifying the process of building highly functional and architecturally complex realtime apps.
Chat capabilities	Accelerates the time to implement rich chat experiences with features such as read receipts, typing indicators, and more.	Ably Yes Ably Chat provides dedicated APIs for building out a scalable chat solution. We support individual and group messaging, typing indicators, room reactions, and more. Learn more about Ably Chat	PubNub Yes But the Chat SDK lacks some advanced features. See PubNub Chat Docs	Accelerates the time to implement rich chat experiences with features such as read receipts, typing indicators, and more.
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	PubNub Partial PubNub's collaboration capabilities are largely powered by its Presence feature. There is no dedicated collaboration SDK.	Enables you to quickly integrate realtime collaborative features like live cursors, member location, avatar stacks, and component locking.
State sync capabilities	Enables realtime data synchronization across devices and users, ensuring a cohesive and up-to-date user experience.	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	PubNub Yes	Enables realtime data synchronization across devices and users, ensuring a cohesive and up-to-date user experience.
Presence	Maintaining a view of which users are connected, and their associated metadata, enables their online status to be updated in realtime.	Ably Yes	PubNub Yes Read more	Maintaining a view of which users are connected, and their associated metadata, enables their online status to be updated in realtime.
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	PubNub Yes PubNub's Presence API allows developers to access and integrate occupancy information into their applications. Read more	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.
Message interactions	Enables interaction with previously-sent messages, facilitating the implementation of features like message reactions and threads.	Ably Partial Message interactions are natively supported in ably-js. There is not currently any API support for retrieving messages and their interactions efficiently from the Realtime service (under development). Learn more	PubNub Yes	Enables interaction with previously-sent messages, facilitating the implementation of features like message reactions and threads.
Message history	Enables clients to catch up on missed messages when inactive, ensuring a user doesn’t miss any important messages.	Ably Yes	PubNub Yes	Enables clients to catch up on missed messages when inactive, ensuring a user doesn’t miss any important messages.
Push notifications	Cross-platform push notifications make it possible to deliver important and timely messages to users even when they’re inactive.	Ably Yes Support for Android and iOS push notifications. Improved web-push for browsers currently in progress.	PubNub Yes	Cross-platform push notifications make it possible to deliver important and timely messages to users even when they’re inactive.
Message delta compression	Minimizes bandwidth and can reduce latency, particularly in scenarios where continuous updates are sent.	Ably Yes Broadcast changes efficiently with our binary deltas, reducing bandwidth consumption by typically up to 95%.	PubNub No	Minimizes bandwidth and can reduce latency, particularly in scenarios where continuous updates are sent.
Programmatic management	Enables the automation of provisioning, management, and testing of service resources, simplifying integration with existing development workflows such as CI.	Ably Yes	PubNub Yes	Enables the automation of provisioning, management, and testing of service resources, simplifying integration with existing development workflows such as CI.
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.	Ably Yes	PubNub Yes	With a free plan, you can test the service’s functionality and compatibility with your project before committing to a paid plan.
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.	PubNub PubNub offers Free, Starter, and Pro packages. Their support packages, separate from their standard plans, also include an Enterprise option. Their pricing model is based on monthly active users (MAUs). See the pricing page	The pricing model should align with your project's expected load, usage patterns, and budget in order to be cost-effective and efficient.
Pricing plans	The pricing plans offered by cost.	Ably The free and paid plans are: Free plan: Up to 6 million monthly messages and 200 concurrent connections Standard plan ($29/month): Up to 10k concurrent connections and channels, and 2.5k messages/second Pro plan ($399/month): Up to 50k concurrent connections and channels, and 10k messages/second Enterprise plan: For committed use, with custom pricing Learn more	PubNub Starter: $98/month/MAU: Up to 1000 MAUs, and up to 3000 transactions per MAU. Pro packages: Custom pricing Their support packages, separate from their standard plans, also include an Enterprise option. Overages apply: $0.15 per additional user $43 per additional 1M transactions	The pricing plans offered by cost.
Integrations & interoperability
SDKs	Supporting multiple languages and platforms offers greater flexibility when building cross-platform realtime apps.	Ably Java Javascript (browsers) React Native React Hooks Android Clojure Cordova / Phonegap Flutter Go iOS Objective-C iOS Swift Kotlin Laravel (PHP) MacOS Mono NativeScript .NET Node.js PHP (REST only) Scala Python Ruby (REST only) tvOS Unity Xamarin + Xamarin.forms	PubNub REST API Asyncio C-Core C-Sharp Cocoa Objective-C Cocoa Swift Dart FreeRTOS Go Java JavaScript Kotlin Lua Mbed MQTT Objective-C PHP POSIX C POSIX C++ Python React Redux Ruby Rust Swift Unity Windows C Windows C++ Source: SDKs	Supporting multiple languages and platforms offers greater flexibility when building cross-platform realtime apps.
Supported realtime protocols	Support for multiple protocols provides the flexibility to choose a protocol that best suits your project’s requirements.	Ably WebSockets MQTT Server-Sent Events (SSE) Fallback to Comet (XHR) and Long Polling for older browsers	PubNub HTTP MQTT Fallback to Comet (XHR) and Long Polling for older browsers PubNub uses HTTP as the transport for their client libraries. A WebSocket compliant interface is provided in some libraries, however this is just a wrapper around an underlying HTTP transport.	Support for multiple protocols provides the flexibility to choose a protocol that best suits your project’s requirements.
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 AWS Lambda Microsoft Azure Functions Cloudflare Workers Google Cloud Functions	PubNub PubNub operates its own serverless architecture through its feature called PubNub 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.
Streaming & queueing	Provides a dependable method to reroute messages from the service to third-party streams and queues for further processing.	Ably Egress: Kafka Kinesis AMQP SQS Pulsar Ably-hosted queues Ingress: Kafka Connector Postgress (via Database Connector) 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.	PubNub Egress: AWS Kinesis AWS SQS Apache Pulsar RabbitMQ AMQP Kafka Ingress: Kafka	Provides a dependable method to reroute messages from the service to third-party streams and queues for further processing.
Observability services	Enables realtime monitoring and troubleshooting by offering insights into service behavior directly in your observability platform of choice.	Ably Yes	PubNub Yes PubNub provides integrations with Datadog and NewRelic.	Enables realtime monitoring and troubleshooting by offering insights into service behavior directly in your observability platform of choice.
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.	Ably Terraform Control API + SDKs	PubNub PubNub provides a Command Line Interface (CLI) specifically for managing and deploying PubNub Functions.	Makes it possible to provision and configure service infrastructure as part of a CI or CD pipeline, enabling repeatable and reliable deployments.
Quality of Service
Scalability	Scalability is vital as it ensures the service can handle increased data load or users without compromising performance.	Ably <50 ms median global latency 2 trillion+ monthly transactions 1 billion monthly device connections 99.999% uptime SLA Unlimited throughput capacity at system level, limitless channel churn rate	PubNub 2 trillion monthly transactions 800 million device connections monthly Under 100 milliseconds delivery 99.999% reliability Source: Edge messaging solutions page	Scalability is vital as it ensures the service can handle increased data load or users without compromising performance.
Guaranteed message delivery	Ensures messages are never lost during transmission, even in the presence of network disruptions.	Ably Yes	PubNub No	Ensures messages are never lost during transmission, even in the presence of network disruptions.
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	PubNub No	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.
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	PubNub No	Guarantees that each message is processed exactly once, preventing data inconsistencies that can arise from duplicate processing or missing messages.
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%.	PubNub PubNub offers a 99.999% uptime SLA for its users.	An uptime guarantee instills confidence in the reliability of the service and protects your business from the negative impacts of downtime.
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 11 geographically-distributed core routing datacenters by default. Ably's network of 700+ edge acceleration points-of-presence is growing day by day.	PubNub Yes	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.
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	PubNub Yes PubNub supports multi-region data replication across different points of presence except for file sharing. Read more	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.
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	PubNub No	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.
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	PubNub <100 milliseconds delivery.	Low latency is crucial for realtime apps as it ensures swift and efficient data transmissions, providing a smoother and more responsive user experience.
Security & compliance
API key authentication	Simplifies the authentication code on trusted servers compared to requesting, managing, and refreshing tokens.	Ably Yes	PubNub Yes	Simplifies the authentication code on trusted servers compared to requesting, managing, and refreshing tokens.
Token-based authentication	Provides a means to securely authenticate user devices against your user management system.	Ably Yes	PubNub Yes	Provides a means to securely authenticate user devices against your user management system.
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	PubNub Yes PubNub implements SAML SSO authentication.	SSO streamlines login processes, boosts security by minimizing password use, and meets compliance needs for secure data access management.
Rules for permissions and operations	Provides control over which users can subscribe and publish to certain channels.	Ably Yes	PubNub Yes PubNub supports rules for permissions and operations through its Access Manager. See Access Manager docs	Provides control over which users can subscribe and publish to certain channels.
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	PubNub Yes PubNub uses AES256 encryption for end-to-end encryption of messages and files. Read more	Ensures that the data transmitted between the client and the API server remains confidential and secure while in transit.
Encryption at rest	Ensures data stored by the service is secure and compliant, while also mitigating the risks of a data breach.	Ably Yes	PubNub Yes	Ensures data stored by the service is secure and compliant, while also mitigating the risks of a data breach.
Compliance	Compliance with regulations can impact your ability to meet legal obligations in your industry.	Ably SOC 2 certified HIPAA compliant EU GDPR compliant Ably also offers EU and US-only data storage.	PubNub PubNub is compliant with five policies for the security and privacy of its services: ISO 27001 SOC 2 Type II HIPAA GDPR CCPA PubNub FAQ page	Compliance with regulations can impact your ability to meet legal obligations in your industry.