Discord error 4011: Sharding required

Your bot is in more guilds than a single gateway connection is allowed to serve, and you identified without sharding (or with too few shards). The documented ceiling is 2,500 guilds per shard; apps in 2,500 or more guilds must shard. Discord closes the connection with 4011 and will not accept an unsharded Identify until the guild count drops or you add shards. It is not reconnectable.

Sharding splits guilds across connections deterministically: a guild lives on shard (guild_id >> 22) % num_shards. You tell Discord your shard layout in the Identify payload's shard array, and each connection then only receives events for its guilds. The GET /gateway/bot endpoint returns a recommended shards value and a session_start_limit with max_concurrency, which governs how many shards may identify per 5 seconds. Libraries implement all of this; you mostly need to turn it on (discord.js ShardingManager or shards: 'auto', discord.py AutoShardedClient).

Hitting 4011 is a milestone: it means the bot grew. But it also means downtime until sharding is enabled, so plan before reaching 2,500.

// WebSocket close frame
code: 4011
reason: "Sharding required"

// GET /gateway/bot
{
  "url": "wss://gateway.discord.gg",
  "shards": 9,
  "session_start_limit": {
    "total": 1000,
    "remaining": 999,
    "reset_after": 14400000,
    "max_concurrency": 1
  }
}

Turn on auto-sharding long before you need it; it costs nothing at small scale. Track guild count as a metric and alert at around 2,000 so capacity planning (and the verification and privileged intent reviews that come with growth) happens on your schedule rather than Discord's.

Sharding thresholds and the identify concurrency that governs multi-shard startup are on the Discord limits page; growth planning for verification and intents, which arrive around the same scale, is covered in Discord bot not responding.