Two managed realtime platforms with real delivery guarantees. The differences are pricing shape, per-channel ceilings, and scope.
Ably is the most engineering-serious platform in this space, with delivery guarantees documented to a depth few vendors attempt. Foony makes similar guarantees with a deliberately smaller surface. What genuinely separates them is how usage is billed and where the ceilings sit.
When Foony fits
One meter, much cheaper. Foony’s subscription tiers include generous limits. You’re only billed for message overages (in and out). Ably bills you multiple times: once for subscription capacity, once for every message, for connection minutes, channel minutes, and data transfer.
No per-channel rate ceiling. Ably caps every channel at 50 messages a second on every tier including Enterprise, so a hot channel must be sharded. Foony’s rate limit is per app, one busy channel may use all of it.
Presence storms fit in the allotment. Ably documents the n-squared cost itself: 200 clients cycling a presence channel is roughly 80,400 billable messages. Foony bills presence the same way, as plain messages, but they land against one meter with 100M included.
Bigger messages on paid plans: 1 MB versus 256 KiB on Ably Pro.
Included volume: $19/month covers 100M messages. Ably Standard is $29 plus usage at $2.50 per million message units. On average, this works out to about a 10x lower bill.
When Ably fits
Protocol breadth: MQTT, SSE, AMQP, and STOMP adapters at no extra charge, which matters for IoT fleets and EventSource-only clients.
An official SDK for nearly every language: Java, Swift, Python, Ruby, .NET, Flutter and more. Foony ships JavaScript and Go, plus Pusher-protocol clients.
Contractual 99.999% SLA and dedicated clusters on Enterprise, with multi-region message redundancy documented in detail.
Longer paid retention when you need it: up to 365 days on Pro versus Foony’s 30.
Guarantees
Foony
Ably
Delivery
Effectively exactly once (idempotent publish, client dedup)
Exactly once semantics via idempotent publish with a 2-minute dedup window
Ordering
Guaranteed per channel, serial-numbered
Guaranteed per publisher over realtime connections
History
Per-prefix channel rules, up to 30 days
2 minutes by default, 24 h to 365 days via channel rules by tier
Encryption
End-to-end AES-GCM, key never leaves your clients
Client-side AES-CBC, keys never reach Ably
Limits and pricing
Foony
Ably
Billing meters
Messages, in and out
Messages per delivery in 5 KiB chunks, connection minutes, channel minutes, data transfer
Competitor numbers last checked July 2026. If something has drifted, tell us and we will fix it.
Moving over
Ably’s channels, presence, history, and token auth all have direct Foony equivalents, so a migration is mechanical: channels keep their names, capabilities translate to Foony capabilities, and history cursors become serial cursors. Channel sharding built to dodge the 50 messages-a-second cap can usually be deleted.
Try it on the free tier
9M messages a month, presence, history, and the Pusher-compatible API are all on the free plan. No card required.