Compress Middleware

This middleware compresses the response body, according to Accept-Encoding request header.

INFO

Note: On Cloudflare Workers and Deno Deploy, the response body will be compressed automatically, so there is no need to use this middleware.

Import

import { Hono } from 'hono'
import { compress } from 'hono/compress'

Usage

const app = new Hono()

app.use(compress())

Options

optional encoding: 'gzip' | 'deflate'

The compression scheme to allow for response compression. Either gzip or deflate. If not defined, both are allowed and will be used based on the Accept-Encoding header. gzip is prioritized if this option is not provided and the client provides both in the Accept-Encoding header.

optional threshold: number

The minimum size in bytes to compress. Defaults to 1024 bytes.

optional contentTypeFilter: RegExp | (contentType: string) => boolean

A RegExp or function to determine whether the response should be compressed based on its Content-Type. By default, a built-in list of compressible Content-Types is used.

You can pass a RegExp to compress only matching Content-Types:

// Compress only JSON responses
app.use(compress({ contentTypeFilter: /^application\/json/ }))

Or pass a function for custom logic. The built-in COMPRESSIBLE_CONTENT_TYPE_REGEX is also exported so you can extend the default behavior:

import {
  compress,
  COMPRESSIBLE_CONTENT_TYPE_REGEX,
} from 'hono/compress'

// Compress the default Content-Types plus a custom one
app.use(
  compress({
    contentTypeFilter: (type) =>
      COMPRESSIBLE_CONTENT_TYPE_REGEX.test(type) ||
      type === 'application/x-myformat',
  })
)