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Long polling and WebSockets are two common techniques for delivering realtime data. While both have been used successfully in production systems, they differ significantly in how they perform, scale, and integrate into modern architectures. This guide compares long polling vs WebSockets to help engineering teams and technical decision-makers choose the right approach for delivering realtime experiences reliably and at scale.

We’re excited to announce Ably LiveObjects, launched with a radical vision: to enable any application to work with live, shared data that synchronizes instantly for users everywhere. Shared access to live data is no longer a nice-to-have - it’s becoming a foundational building block of every realtime digital experience.

Not every message in a realtime app needs to be available in message history, like in the rewind backlog or in persistent storage. Ably is introducing ephemeral messages to let you deliver transient updates - like reactions, typing indicators, or cursor positions - which are only delivered to clients that are connected at the moment the message is published.

As your user base expands, so does the volume and variety of push notifications you need to send. Whether it’s transactional alerts, updates, or personalized messages, publishing notifications for thousands - or even millions - of users can quickly become a bottleneck. The more you grow, the more important it becomes to have a scalable, efficient push strategy.

At Ably's February fan engagement event, Sam Renouf, CEO of the Professional Triathletes Organisation (PTO), captured the essence of impactful fan engagement with an observation about motorsports: Sam's insight points to a transformation across sports, and fan experiences more generally: that effective engagement now depends on meaningful realtime data storytelling.

Fan engagement strategies are evolving rapidly. But how do organizations ensure they are delivering realtime data with real meaning to their customers? As a veteran of the sports media industry with 35 years of experience at Deltatre, Carlo De Marchis (A Guy With a Scarf) recently gave a keynote at Ably’s fan engagement summit in February, and explored exactly this question - what should companies actually be trying to achieve when building a fan engagement strategy? His answer was concise.

High-scale, high-frequency messaging and burst activity can lead to significant costs and performance challenges for realtime applications. To help with this, we’ve introduced server-side batching and conflated subscriptions—two powerful optimizations in Ably Pub/Sub that significantly reduce message count, lower bandwidth usage, and optimize processing overhead. These features allow you to process high-frequency updates more efficiently without sacrificing accuracy, reliability, or latency.

For some realtime applications, the latest state matters more than the full stream of updates. If you’re tracking stock prices, monitoring live sports scores, or displaying GPS locations, you don’t need to process and transmit every intermediate update—just the most recent one. To help you minimize bandwidth usage, processing costs, and system load, we’ve introduced conflated subscriptions to Ably Pub/Sub.

Motorsports have always been synonymous with speed, precision, and innovation—both on the track and in the way they engage fans. In an era where digital experiences define audience expectations, realtime data has become the driving force behind deeper, more immersive fan engagement.

Realtime features make apps feel modern, collaborative, and up-to-date. The features predominantly require sharing changes triggered by one user to other users, as the changes are happening. This typically means your server needs to send data to some set of clients, where those clients don’t know they are missing the data. These patterns rely on a connection between the client and the server, where the server can notify the client of some data.