Ably vs Pusher vs Supabase Realtime: Real-Time APIs in 2026

You need a real-time service when your users expect instant updates without refreshing the page: live chat, collaborative editing, notifications, dashboards with live data, multiplayer features, or auction bidding. Building this infrastructure yourself means managing WebSocket servers, handling connection state across millions of clients, implementing reconnection logic, and ensuring message ordering and delivery guarantees.

Most teams should not build this from scratch. The engineering effort to build reliable real-time infrastructure (handling disconnections, reconnections, message ordering, and horizontal scaling) is 2 to 4 months of dedicated backend work. Managed services handle the hard parts and let you focus on your product logic.

The three leading options each take a different approach: Ably is enterprise-grade pub/sub with guaranteed message delivery, Pusher is the developer-friendly OG with the simplest API, and Supabase Realtime leverages PostgreSQL change streams for database-driven real-time features. Your choice depends on your reliability requirements, your existing stack, and your scale trajectory.

For a broader look at the underlying protocols and when to use each, check our WebSockets vs SSE comparison.

Ably positions itself as the most reliable real-time platform, and their architecture backs it up. Messages are replicated across multiple data centers with guaranteed delivery, ordering, and exactly-once semantics. If a client disconnects and reconnects, Ably automatically replays missed messages.

Key Features

• Message persistence: Messages are stored for 24 to 72 hours (configurable), enabling history retrieval and catch-up after disconnection
• Presence: Track which users are online in a channel with automatic enter/leave events
• Message ordering: Global ordering guarantees within a channel
• Protocol support: WebSocket, SSE, MQTT, and REST fallbacks
• Integrations: Webhook triggers, queue rules (push messages to SQS, Kafka, AMQP), and serverless function triggers

Pricing

Free: 6M messages/month, 200 concurrent connections. Standard: $29/month for 12.5M messages. Pro: $99/month for 50M messages. Enterprise: custom pricing. Messages are the billing unit, which can add up fast for chatty applications (a 100-user chat room sending 1 message/second generates 2.6M messages/month).

Best For

Fintech (trade execution, live pricing), IoT (device telemetry), and collaboration tools where message delivery guarantees are non-negotiable. If losing a single message has business consequences, Ably is the right choice.

Pusher has been in the real-time space since 2010 and remains the simplest option to integrate. Their Channels product handles pub/sub messaging, and their SDK is available in every major language. Most developers can go from zero to a working real-time feature in under 2 hours.

Key Features

• Channels: Public, private (authenticated), presence (track online users), and encrypted channels
• Client events: Peer-to-peer messaging between clients without hitting your server
• Webhooks: Notifications for channel activity (occupation, vacation events)
• Pusher Beams: Separate product for push notifications (iOS and Android)

Pricing

Free: 200K messages/day, 100 concurrent connections. Startup: $49/month for 500 connections, 1M messages/day. Business: $99/month for 2K connections, 4M messages/day. Pro: $299/month for 10K connections. Enterprise: custom. Connection-based pricing, which is more predictable than message-based for applications with variable message frequency.

Limitations

No built-in message persistence (messages are fire-and-forget). If a client is offline when a message is sent, they miss it. No message ordering guarantees across channels. The 10KB message size limit constrains large payloads. These limitations matter for applications that need reliability guarantees but are fine for notifications, live updates, and basic chat.

Best For

Startups that want the fastest integration, live dashboards, notification systems, and simple chat features. If your real-time needs are straightforward and you value developer velocity over enterprise features, Pusher is the pragmatic choice.

Supabase Realtime takes a fundamentally different approach. Instead of a general-purpose pub/sub system, it streams database changes to connected clients. Insert a row in PostgreSQL, and every subscribed client receives the new data instantly.

Key Features

• Postgres Changes: Subscribe to INSERT, UPDATE, DELETE events on specific tables with row-level security filtering
• Broadcast: General-purpose pub/sub for messages that do not involve database changes (typing indicators, cursor positions)
• Presence: Track online users with shared state (user typing, user viewing page)
• Row-level security: Real-time subscriptions automatically respect your PostgreSQL RLS policies, so users only receive updates they are authorized to see

Pricing

Part of the Supabase platform. Free: 200 concurrent connections, 2M messages/month. Pro ($25/month): 500 connections, 5M messages/month. Additional connections and messages available as add-ons. The pricing is competitive because real-time is bundled with your database, auth, and storage.

Limitations

Tied to the Supabase ecosystem. Real-time subscriptions are most useful when your data lives in Supabase's PostgreSQL. Broadcast and Presence work independently, but the core value proposition (streaming database changes) requires Supabase as your database. Message throughput is lower than dedicated real-time services at high scale. No message persistence or history replay.

Best For

Applications where real-time features are driven by database state: live dashboards, collaborative lists, real-time inventory, and multiplayer apps built on Supabase. If your data is already in Supabase, adding real-time features is nearly zero additional development effort. For building collaboration features specifically, check our collaboration tool guide.

Latency

Ably: 50 to 100ms globally (multi-region edge network). Pusher: 70 to 150ms (single-region with CDN). Supabase Realtime: 80 to 200ms (depends on your Supabase project region). For most applications, all three are fast enough. For latency-critical applications (live bidding, trading), Ably's edge network provides a measurable advantage.

Reliability

Ably: 99.999% uptime SLA on enterprise plans, with message delivery guarantees and automatic failover across data centers. Pusher: 99.997% historical uptime, but no formal delivery guarantees (messages can be lost during outages). Supabase Realtime: tied to Supabase's overall uptime (99.9% SLA on Pro), which is good but not enterprise-grade.

Scaling

Ably: handles millions of concurrent connections per account. Tested at 1B+ messages per day. Pusher: handles tens of thousands of concurrent connections per app. For higher scale, you need Enterprise. Supabase Realtime: handles hundreds of concurrent connections per project on Pro. Higher limits on Enterprise. For a chat app with 10K concurrent users, Ably and Pusher handle it natively. Supabase Realtime would need a Team or Enterprise plan.

Message Guarantees

This is the biggest differentiator. Ably guarantees message delivery and ordering. If a client disconnects for 30 seconds, reconnects, and Ably replays every missed message in order. Pusher and Supabase Realtime do not guarantee delivery: messages sent while a client is disconnected are lost. For notifications ("your order shipped"), this is acceptable. For financial transactions or collaborative editing, it is not.

SDK Quality

All three offer SDKs for JavaScript, React, Python, Ruby, Go, and other major languages. Pusher's JavaScript SDK is the most battle-tested and has the simplest API (3 lines to subscribe to a channel and receive events). Ably's SDK is more complex but exposes more features (connection state management, channel rewind). Supabase's SDK integrates real-time into their broader client library, which is convenient if you already use Supabase for auth and database.

Framework Integration

Supabase has the best React hooks integration (useRealtime, usePresence) because real-time is built into the Supabase client. Ably provides React hooks via their @ably/react package. Pusher requires slightly more boilerplate but has maintained React and Next.js examples for years.

Debugging and Monitoring

Ably: detailed dashboard showing message flow, connection states, channel statistics, and message history. You can replay individual messages for debugging. Pusher: dashboard with connection counts and message volume. The debug console shows real-time event streams but lacks message history. Supabase: real-time logs in the Supabase dashboard, plus PostgreSQL query logs for database change events. Less purpose-built monitoring than Ably.

Self-Hosted Alternative

If you want full control, Supabase's entire stack (including Realtime) is open-source and self-hostable. Ably and Pusher are proprietary with no self-hosted option. For teams that need data sovereignty or want to avoid vendor lock-in, Supabase's open-source nature is a significant advantage.

Here is the decision framework:

• Choose Ably if you need guaranteed message delivery and ordering, your application handles financial transactions, IoT telemetry, or critical notifications, you need multi-protocol support (MQTT for devices, WebSocket for web), or you are building at scale (1M+ concurrent connections).
• Choose Pusher if you want the fastest integration with the simplest API, your real-time needs are straightforward (notifications, live updates, basic chat), fire-and-forget messaging is acceptable, or you are building an MVP and want to ship real-time features in a day.
• Choose Supabase Realtime if your data already lives in Supabase, your real-time features are database-driven (live dashboards, collaborative CRUD), you want real-time plus database plus auth in a single platform, or you value the open-source and self-hostable option.

For most startups building their first real-time feature: start with Pusher for simplicity, or Supabase Realtime if you are already on Supabase. Migrate to Ably if your reliability requirements increase as you scale. The migration is not trivial (different APIs) but is manageable over a 2 to 4 week sprint.

Need help choosing or implementing real-time features for your product? Book a free strategy call and we will recommend the right approach based on your specific requirements and scale.