Ably can support very large message payloads, however Ably is designed to be a realtime messaging platform that delivers small payloads incredibly quickly anywhere in the world. As such, we have sensible defaults enforced on our accounts that encourages developers to use smaller payloads and deliver them as quickly as possible. If you have a larger message size requirement, please raise a ticket and explain what message size you require along with an explanation and we'll do what we can to help.
Enterprise account message size limit
Configurable based on custom package for customer. The default for Enterprise accounts is 64kb, however theoretically this can be increased to 256kb based on each customer's use case. Please get in touch to discuss your needs.
Paid account message size limit (default)
64KB (65,536 bytes)
Free account message size limit (default)
16KB (16,384 bytes)
Please get in touch if you have any questions or are having any problems message size constraints.