NoLag vs Ably
Ably is a mature, managed realtime platform known for pub/sub, presence, message history, and strong delivery guarantees. NoLag has the same pub/sub and presence foundation, but it is open-source software you run yourself: the Apache-2.0 kraken broker, plus client SDKs and blueprint SDKs for common app patterns.
Short version: if you want a battle-tested service with message history and rich delivery semantics, and you would rather not operate anything, Ably is a strong choice. If you want realtime on your own infrastructure with no vendor lock-in, and higher-level SDKs to ship common patterns quickly, NoLag is built for that.
At a glance
| NoLag | Ably | |
|---|---|---|
| Core model | Realtime pub/sub over WebSocket | Realtime pub/sub over WebSocket |
| Hosting | Self-hosted: one kraken container plus your auth | Managed service |
| High-level SDKs | Blueprints for chat, notify, feed, dashboards, tracking, sync, and more | Pub/sub, presence, history primitives |
| Delivery | Presence, acknowledged publishes, per-message QoS on an MQTT backend; no message history or replay | Presence, history, delivery guarantees |
| Authentication | Actor tokens with per-topic ACL; short-lived browser JWTs with @nolag/core | Token auth with capabilities, JWT support |
| SDKs | JavaScript/TypeScript (including React Native), Go, Python | Client and server libraries across many languages |
Where NoLag is different
- Open source, on your own infrastructure. kraken is Apache-2.0 and runs as a single container, so messages stay on your servers and there is no vendor lock-in. The trade is that you operate it.
- Blueprint SDKs. A domain-specific API for chat, notifications, dashboards, tracking, and more, so you skip the plumbing.
- Actor-based auth. Every credential resolves to a typed actor (such as user, device, service or session) whose permissions live server-side as per-topic ACL, not baked into each token. With @nolag/core, your backend mints short-lived browser JWTs signed with a project signing key, with no network call to issue one, so a leaked token expires on its own within minutes.
Where Ably is a strong fit
- A mature, widely trusted managed platform, with nothing for you to operate.
- Rich delivery semantics and message history out of the box.
- Broad official SDK coverage.
When to choose NoLag
- You want realtime on your own infrastructure, under an open-source licence.
- You want higher-level SDKs to ship common realtime patterns quickly.
- You already keep message history in your own database and want a messaging layer, not a store.
Try it
Follow the 5-minute quick start, read the self-hosting guide, then look at the high-level SDKs.