Limits

Keel has no usage quotas or bills: how much you can store and serve depends on your hardware. It does have limits that protect the server and your users, such as upload sizes, time limits and rate limits. This page lists all of them, with their defaults and how to change them.

Settings in .env take effect after ./keel up. "Fixed" means the value is built into Keel. "Compose file" means you change the service's settings in Docker Compose, in a docker-compose.override.yml next to docker-compose.yml, so updates don't conflict with your changes (see Configuration).

Projects

Limit	Value	How to change
Project name	3 to 40 characters: lowercase letters, digits and dashes, starting with a letter and ending with a letter or digit, no --	Fixed
Reserved project names	api, auth, rest, storage, realtime, functions, studio, health, keel, postgres, template0, template1, admin, assets, static, graphql, docs	Fixed
Projects per server	No set limit. Each project runs its own PostgREST process and uses database connections, so memory and max_connections are the practical limits.
API key lifetime	10 years from when the project was created	Fixed

Database

Limit	Default	How to change
Postgres max_connections	100 (Postgres's default)	alter system set max_connections = 200;, then restart the stack (see Connecting directly)
Statement timeout for API requests	3 s as anon, 8 s as authenticated	Fixed (re-applied on every start)
Rows per REST response	1,000. Use .range() or limit/offset to page through more.	Per project: max_rows in the project's settings (see Exposing other schemas). For every project: compose file, KEEL_POSTGREST_MAX_ROWS in the keel-rest service's environment
Logical replication slots and senders	32 each. Realtime uses one slot per project that has database-change subscribers.	Compose file: max_replication_slots and max_wal_senders in the keel-db command
Slow query log threshold	200 ms	KEEL_SLOW_QUERY_MS (-1 turns it off)

Each project's services open database connections as they need them: PostgREST up to 10, auth and storage up to 10 each, and a few more for realtime and Studio. With many busy projects, raise max_connections and make sure the server has the memory for it.

Studio

Limit	Value	How to change
Session length	12 hours	Fixed
Failed sign-in attempts	10 per address per 15 minutes (a successful sign-in resets the count); 20 per account per hour from the internet	Fixed
SQL editor statement timeout	60 seconds	Fixed
SQL editor result rows shown	1,000 per statement	Fixed
SQL per run	2 MB	Fixed
Table browser	50 rows per page, 15-second query timeout	Fixed
Users list	First 100 users matching the search	Fixed
Files list	1,000 entries per folder	Fixed
Backup download links	Valid for 1 minute, only in the Studio session that made them	Fixed
Minimum secret lengths in .env	KEEL_SECRET 32, POSTGRES_PASSWORD 12, KEEL_DASHBOARD_PASSWORD 8 characters	Fixed

Backups

Limit	Default	How to change
Nightly backup time	03:00 (container time zone, TZ)	KEEL_BACKUP_SCHEDULE (HH:MM, or off)
Nightly backups kept per project	7	KEEL_BACKUP_RETENTION
Manual backups	Kept until you delete them
Full backups kept on the server	2	KEEL_BACKUP_KEEP_LOCAL
Full backups kept in the backup target	Newest of each of the last 7 days and 4 weeks	Studio, Backups > Schedule
Backup passphrase	12 characters or more
Backups listed in Studio	The latest 100 per project	Fixed

Auth

Limit	Default	How to change
Access token (JWT) lifetime	3,600 s (1 hour)	Studio: Users, Sign-in settings, Session token lifetime (60 s to 7 days)
Reuse window for a rotated refresh token	10 seconds	Fixed
Password length	At least 6 characters, at most 72	Minimum: Sign-in settings, Minimum password length (6 to 72)
Email links and codes	6-digit code, valid for 1 hour, single use	Fixed
Time between emails to one address	60 seconds (per kind of email)	Fixed
Emails per address	6 per hour	Fixed
Password sign-in attempts	10 per 5 minutes per IP address and email (or phone)	Fixed
Wrong passwords per account	20 per hour from all addresses together; after that each attempt waits twice as long as the one before, up to 5 minutes. Addresses that signed in to the account in the last 30 days aren't held up, so someone guessing can't lock the owner out.	Fixed
Password checks at once	4 for the whole keel-auth service; up to 64 more wait at most 2 seconds, the rest get 503 (request_timeout)	Fixed
Token requests (sign-in and refresh)	120 per 5 minutes per IP address	Fixed
Link and code verifications	30 per 5 minutes per IP address, and 10 code guesses per hour per email or phone	Fixed
SMS code lifetime	60 seconds	Sign-in settings, Code expires after (30 to 3,600 s)
SMS code length	6 digits	Sign-in settings, Code length (6 to 10)
SMS sending	60 seconds between codes to one number; 6 per hour per number; 10 per hour per IP address; 60 per hour per project	Fixed. Test numbers are exempt.
MFA factors per user	10	Fixed
MFA challenge lifetime	5 minutes	Fixed
MFA verification attempts	10 per 5 minutes per user	Fixed
SMS second-factor codes	One every 15 seconds	Fixed
PKCE auth code and OAuth state	10 minutes	Fixed
Users per page in the admin API	50 by default, up to 1,000 (per_page)	Per request
JSON request body	1 MB	Fixed

All auth limits apply per project. Limits "per IP address" use the address that connects to keel-gateway; addresses that clients put in X-Forwarded-For are ignored. Behind a reverse proxy on the same machine (Caddy, nginx, tailscale serve), that address is the proxy's, so all users behind it share those limits.

Storage

Limit	Default	How to change
Largest upload	500 MB (524,288,000 bytes) with the installer and on ZimaOS, 50 MB (52,428,800 bytes) when built from source; for regular and resumable uploads	KEEL_STORAGE_MAX_FILE_SIZE (bytes)
Bucket file size limit	None (the server-wide limit applies)	Per bucket, in Studio or with updateBucket. It can only lower the server-wide limit.
Bucket name	1 to 100 characters: letters, digits, spaces, ., _ and -, starting with a letter or digit	Fixed
Reserved bucket names	public, authenticated, sign, info, list, move, copy, upload, render	Fixed
Object name	Up to 1,024 characters; no leading /, no . or .. segments, no backslashes	Fixed
Objects per list request	100 by default, up to 1,000	Per request (limit)
Signed download URLs	Valid for the expiresIn you pass	Per request
Signed upload URLs	Valid for 2 hours	Fixed
Resumable uploads (TUS)	Any chunk size; unfinished uploads are deleted after 24 hours; Upload-Defer-Length isn't supported	Fixed
Image transformations	Width and height 1 to 2,500 px, quality 20 to 100 (default 80), source images up to 50 megapixels	Fixed

Realtime

Limit	Value	How to change
WebSocket message size	1 MB (a bigger message closes the connection)	Fixed
Messages per connection	100 per second, with bursts of up to 200. Extra messages are refused with RateLimitReached; a client that keeps flooding is disconnected.	Fixed
Messages waiting to be handled per connection	500, or 8 MB	Fixed
Unread data per connection	16 MB queued for a client that doesn't read; then it's disconnected	Fixed
Channels per connection	100	Fixed
postgres_changes listeners per channel	100 (a join asking for more is refused with TooManyBindings)	Fixed
Topic (realtime: plus the channel name)	255 bytes, no control characters	Fixed
Presence state	64 KB per tracked entry (key and state as JSON)	Fixed
Presence entries per connection	One per channel, on up to 10 channels at once	Fixed
HTTP broadcast request body	1 MB	Fixed
HTTP broadcast messages	100 per request, for at most 20 different private topics	Fixed
Filters per postgres_changes listener	1	Fixed
Channel lifetime	Until the user's access token expires (checked every 15 seconds), unless the client sends a fresh token	Fixed
Database-change streaming	Starts with the first subscriber in a project and stops about a minute after the last one leaves	Fixed
Messages in realtime.messages	Deleted after 24 hours	Fixed
Connections per client address	200 per project (an IPv6 client counts per /64); more get 429	KEEL_REALTIME_MAX_PER_IP
Anonymous connections per project	10,000 sockets that haven't joined a channel with a user's token. Past that, a new socket is let in but closed after 10 seconds unless it joins a channel with a user's token. Signed-in users and the service role key are not counted.	KEEL_REALTIME_MAX_PER_PROJECT

Edge functions

Limit	Default	How to change
Memory per function	256 MB	KEEL_FUNCTIONS_MEMORY_MB
Time per request	150 seconds (then 504 with WORKER_TIMEOUT)	KEEL_FUNCTIONS_TIMEOUT (seconds)
Idle time before a function's process stops	300 seconds	KEEL_FUNCTIONS_IDLE (seconds)
Functions running at once, across all projects	20. At the limit, the function that has been idle longest is stopped to make room.	KEEL_FUNCTIONS_MAX_WORKERS
Startup time	90 seconds, including downloading npm: and jsr: packages on first use	KEEL_FUNCTIONS_BOOT_TIMEOUT (seconds)
Function name	1 to 63 characters: letters, digits, - and _, starting with a letter	Fixed
Source per function	20 MB and 500 files in total; paths up to 300 characters	Fixed
Single file when deploying from the CLI or a Studio folder upload	5 MB, text only (binary files are skipped)	Fixed
Secret names	Up to 128 letters, digits and underscores, not starting with a digit. Names Keel sets (SUPABASE_URL, SUPABASE_ANON_KEY, SUPABASE_SERVICE_ROLE_KEY, KEEL_*, DENO_* and a few system variables) are reserved.	Fixed
Logs kept for Studio	The last 1,000 console lines and 200 requests per function, until keel-functions restarts	Fixed

See Runtime and limits for what functions can and can't do.

Scheduled jobs and outgoing requests

Limit	Default	How to change
Time per cron run	300 seconds, then the run is stopped and marked failed	KEEL_CRON_TIMEOUT (seconds)
Cron jobs of one project running at once	4. A job due while at the limit runs at its next turn.	KEEL_CRON_MAX_RUNNING
Cron run history (cron.job_run_details)	7 days	KEEL_CRON_HISTORY_DAYS
Shortest cron interval	1 second ('1 seconds')	Fixed
Active cron jobs per project	1,000; jobs past that don't run (a warning is logged)	Fixed
Size of a cron job's command	1 MB	Fixed
Time per HTTP request (net.http_*, webhooks)	60 seconds, or less with timeout_milliseconds	KEEL_NET_MAX_TIMEOUT_MS
HTTP response kept	1 MB; larger responses fail	KEEL_NET_MAX_RESPONSE_BYTES
HTTP requests of one project in flight at once	8	KEEL_NET_CONCURRENCY
HTTP requests waiting to be sent, per project	10,000; further net.http_* calls raise an error, and webhooks skip the request with a warning	Fixed
Size of an HTTP request	URL 32 KB, headers 64 KB, body 5 MB; larger requests raise an error	Fixed
HTTP responses kept (net._http_response)	6 hours	KEEL_NET_TTL_HOURS

Database connections

Each cron run opens a database connection of its own (as the project's owner role) and closes it when the run ends, as pg_cron does by default. At most KEEL_CRON_MAX_RUNNING runs per project are open at once, so with the defaults cron can hold up to 4 connections per project, on top of about 3 for the scheduler itself and 3 for keel-egress per project with queued requests.

Postgres allows 100 connections in all (max_connections), shared by every project's PostgREST pool, auth, storage, realtime, Studio and your own clients. On a server with many projects or busy jobs, keep KEEL_CRON_MAX_RUNNING low, or raise max_connections with KEEL_DB_SETTINGS="max_connections=200" (each connection takes a few MB of memory). When Postgres is out of connections, a run fails with sorry, too many clients already in cron.job_run_details.

See Scheduled jobs and Database webhooks.