All accounts have limits described below.  Enterprise packages offer complete flexibility over any limits configured on an account.  Please get in touch if you would like to discuss a custom package for your business.


Before you get into the details of each limit, you may be interested to:


All account limits: 



Free packages
Paid Self-service & Business packages
 Enterprise packages
 Connections
 Peak connections (max number of concurrent connections used within a single month)
100
Configurable, see our pricing page
Custom or unlimited
 Hard limit on connections (account will block connections)
Yes, 100
Generally you only pay for your overages.
However, if you exceed your provisioned connections by more than 2.5x then we impose a hard limit.
Bespoke hard limits are designed to be unreachable.
 
 Messages
 Max messages per month (messages and presence published & received + history, find out more)
3 million
Configurable, see our pricing page
Custom or unlimited
 Max messages per hour (why are there hourly limits?)
41,700
Total monthly messages / 72. Read more here.
Custom or unlimited
 Max bandwidth per month (for all messages and presence events, find out more)
5.7GiB
Total monthly messages * 2KiB, see our pricing page (e
Custom or unlimited
 Max bandwidth per hour
0.08GiB
Total hourly messages * 2KiB
Custom or unlimited
 Hard limit if message or bandwidth exceeded (account will block publishing)
Yes
Generally you only pay for your overages.
However, if you exceed your provisioned messages or bandwidth by more than 2.5x then we impose a hard limit.
Bespoke hard limits are designed to be unreachable.
 Max message size
16KiB
64KiB
Custom, up to 256kb
Max message (publish & subscribe) rate per second
(why are there per second rate limits?)
35 per second
6.25x burst from your pre-paid hourly quota (equivalently: hourly quota / 576)
Custom or unlimited
 
 Rate & channel limits 




 Peak concurrent channels (max number of open & active channels used within a single month).
100
Configurable, see our pricing page
Custom or unlimited
 Hard limit if channels exceeded (account will block new channels)
Yes, 100
Generally you only pay for your overages.
However, if you exceed your provisioned connections by more than 2.5x then we impose a hard limit.
Bespoke hard limits are designed to be unreachable.
 Max subscribers on a channel. Find out more about subscribing to channels.
Unlimited
Unlimited
Unlimited
 Max members present on a channel.
 Find out more about why presence limits exist, and what happens when a presence limit is hit.
50
200
Custom
 Max publish rate on a realtime connection
15 per second
50 per second
Custom
 Max receive rate on a realtime connection
15 per second
50 per second
Custom
 Max per-channel message rate
15 per second
50 per second
Custom
 Max number of channels per connection. Find out more about this limit and how to deal with it
50
200
Custom
 API requests using the REST API (excluding any token requests)
20 per second
Min 50 per second
Scales up based on messages purchased
Custom
 Token requests             
50 per second
Min 125 per second
Scales up based on peak connections purchased
Custom
 
 Reactor Queue limits
 Find out more about the Ably Reactor
 Max queue size (total number of messages stored across all of your configured queues i.e. you could have two queues with capacity for 25k or one with capacity for 50k)
10,000
50,000
Custom
 Max queue message TTL (total time a message will exist in a queue before it's consumed)
1 hour
24 hours
Custom
 Max number of queues per account
5
50
Custom
 Max messages published into the queues from all pub/sub channels per second
100
200
Custom
 
 Reactor Events and Function limits
 Find out more about the Ably Reactor Events
 Max number of WebHook messages per second
50
100
Custom
 Max number of Function (AWS Lambda, Azure Functions, Google Cloud Functions etc) invocations per second
15
30
Custom
 Max concurrently-running Azure Function or Google Cloud Function invocations (note: limit does not apply to AWS lambda as lambda events use the async 'event' invocationType, so the request duration is not an issue)
30
60
Custom
 
 Reactor Firehose
 Find out more about the Ably Reactor Firehose
 Max number of messages per second
Enterprise only
Enterprise only
Unlimited


Further reading