Photon Engine · Rate Limits

Photonengine Rate Limits

Photon does not rate-limit its Realtime transport protocol the way a REST API throttles requests per minute. Instead, capacity is governed by the purchased Concurrent Users (CCU) plan (see plans/photonengine-plans-pricing.yml), and Photon publishes a fair-use guideline - not a hard-enforced cap - on messages per second per room, plus hard technical limits on message size and unreliable-command buffering. The Room Lifecycle WebHooks and Custom Authentication HTTP callbacks (outbound from Photon to the developer's server) are not documented with an explicit rate limit, but respond within the same room-join / operation flow they are triggered from, so slow webhook responses can delay gameplay operations.

Photonengine Rate Limits is the machine-readable rate-limit profile for Photon Engine on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 5 rate-limit definitions, measuring messages, concurrent_users, bytes, and commands.

The profile also includes 3 backoff/retry policies defined and response codes documented for operationFailed and webhookFailed.

Tagged areas include Gaming, Multiplayer, Realtime, Rate Limiting, and Fair Use.

5 Limits
GamingMultiplayerRealtimeRate LimitingFair Use

Limits

Messages Per Second Per Room (fair use) room
messages
500
Photon recommends keeping combined inbound+outbound messages per second per room under ~500; not hard-enforced, but rooms that greatly exceed it are subject to Photon's fair-use policy and may be throttled or the account contacted.
Concurrent Users (CCU) application
concurrent_users
see plans/photonengine-plans-pricing.yml
The actual capacity ceiling is the purchased CCU plan; exceeding it can cause connection refusals until the plan is upgraded or CCU Burst (500+ CCU plans) absorbs the spike.
Message / Payload Size connection
bytes
1200
Messages larger than ~1.2 KB (including protocol overhead) are split across multiple UDP packets by the client SDK.
Per-Client Buffer Size connection
bytes
500000
On Photon Cloud, a client that fills its outgoing buffer (roughly 500 KB) in a short period is disconnected by the server.
Unreliable Command Queue connection
commands
20
LoadBalancingPeer.LimitOfUnreliableCommands defaults to 20 queued unreliable commands.

Policies

Fair Use, Not Hard Throttling
Photon Realtime relies on a fair-use policy for messages-per-second rather than issuing HTTP-style 429 responses; there is no request-based throttling because there is no request-response REST surface for gameplay traffic.
CCU Burst
500+ CCU plans include a temporary burst allowance above the plan's CCU ceiling at no extra charge, smoothing short spikes without a hard cutoff.
WebHook / Custom Auth Timeout Sensitivity
Because WebHooks and Custom Authentication are called synchronously within a room-join or property-change operation, a slow-responding developer-hosted endpoint is experienced by players as added latency or a failed operation rather than a rate-limit error.

Sources