This page describes production limits for Firestore in Datastore mode.

Firestore in Datastore mode limits

Limit Amount
Maximum API request size.

This limit applies when Datastore mode is used outside of Google App Engine. If Datastore mode is used from App Engine, the limit depends on the client library that is used.

10 MiB
Maximum size for a transaction 10 MiB
Maximum size for an entity 1,048,572 bytes
(1 MiB - 4 bytes)
Maximum size for an entity key 6 KiB
Maximum depth of nested entity values 20

Maximum sustained write rate to an entity

Sustaining a write rate above once per second increases latency and causes contention errors. This is not a hard limit, and you can surpass the limit in short bursts.

1 per second
Maximum number of entities that can be passed to a Commit operation in the Datastore API 500
Maximum number of keys allowed for an AllocateIds operation in the Datastore API 500
Maximum number of keys allowed for a Lookup operation in the Datastore API 1,000
Maximum size of an indexed string property's UTF-8 encoding 1,500 bytes
Maximum size for an unindexed property 1,048,487 bytes
(1 MiB - 89 bytes)
Maximum sum of the sizes of an entity's composite index entries 2 MiB
Maximum number of composite indexes for a project 200
Maximum sum of the following for an entity:
  • the number of indexed property values
  • the number of composite index entries
Maximum total number of both export and import requests for a project allowed per minute 20
Maximum number of concurrent exports and imports 50
Maximum number of entity filters for export and import requests

When the export or import request specifies an entity_filter, each combination of filtered kind and namespace counts as a separate filter towards this limit. For example:

A request with kinds=['foo', 'bar'] and namespace_ids=['', 'ns1']
results in 4 filters towards this limit: [('', 'foo'), ('', 'bar'), ('ns1', 'foo'), ('ns1', 'bar')]


Datastore limits

If you have not yet upgraded from Datastore to Firestore in Datastore mode, the following limits also apply to your database instance:

Limit Amount
Maximum number of entity groups that can be accessed in a transaction 25
Maximum rate of transactions reading from or writing to an entity group 1 per sec
Maximum write rate to an entity group.

Note you can batch writes together for an entity group. This allows you to write multiple entities to an entity group within this limit.

1 per second

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