# Bun Enable compression for WebSocket messages

> Enable compression for WebSocket messages

- Skill: `jarle/bun-enable-compression-for-websocket-messages` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jarle/bun-enable-compression-for-websocket-messages`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jarle/bun-enable-compression-for-websocket-messages/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jarle (https://skillmd.com/u/jarle)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/jarle/bun-enable-compression-for-websocket-messages

---


# Enable compression for WebSocket messages

Per-message compression can be enabled with the `perMessageDeflate` parameter. When set, all messages will be compressed using the [permessage-deflate](https://tools.ietf.org/html/rfc7692) WebSocket extension.

```ts server.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
Bun.serve({
  // ...
  websocket: {
    // enable compression
    perMessageDeflate: true,
  },
});
```

***

To enable compression for individual messages, pass `true` as the second parameter to `ws.send()`.

```ts server.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
Bun.serve({
  // ...
  websocket: {
    async message(ws, message) {
      // send a compressed message
      ws.send(message, true);
    },
  },
});
```