https://github.com/fastify/fastify-compress
Fastify compression utils
https://github.com/fastify/fastify-compress
brotli compression deflate fastify fastify-plugin gzip
Last synced: 24 days ago
JSON representation
Fastify compression utils
- Host: GitHub
- URL: https://github.com/fastify/fastify-compress
- Owner: fastify
- License: mit
- Created: 2017-11-08T23:19:05.000Z (over 7 years ago)
- Default Branch: main
- Last Pushed: 2025-03-30T21:24:21.000Z (about 1 month ago)
- Last Synced: 2025-04-06T00:01:41.713Z (about 1 month ago)
- Topics: brotli, compression, deflate, fastify, fastify-plugin, gzip
- Language: JavaScript
- Homepage: https://npmjs.com/package/@fastify/compress
- Size: 398 KB
- Stars: 210
- Watchers: 20
- Forks: 47
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-fastify - `fastify-compress`
README
# @fastify/compress
[](https://github.com/fastify/fastify-compress/actions/workflows/ci.yml)
[](https://www.npmjs.com/package/@fastify/compress)
[](https://github.com/neostandard/neostandard)
Adds compression utils to [the Fastify `reply` object](https://fastify.dev/docs/latest/Reference/Reply/#reply) and a hook to decompress requests payloads.
Supports `gzip`, `deflate`, and `brotli`.
> 🛈 Note: In large-scale scenarios, use a proxy like Nginx to handle response compression.
> âš Warning: Since `@fastify/compress` version 4.x, payloads compressed with the `zip` algorithm are not automatically uncompressed. This plugin focuses on response compression, and `zip` is not in the [IANA Table of Content Encodings](https://www.iana.org/assignments/http-parameters/http-parameters.xml#content-coding).
## Install
```
npm i @fastify/compress
```
### Compatibility
| Plugin version | Fastify version |
| ---------------|-----------------|
| `>=8.x` | `^5.x` |
| `>=6.x <8.x` | `^4.x` |
| `>=3.x <6.x` | `^3.x` |
| `^2.x` | `^2.x` |
| `>=0.x <2.x` | `^1.x` |
Please note that if a Fastify version is out of support, then so are the corresponding versions of this plugin
in the table above.
See [Fastify's LTS policy](https://github.com/fastify/fastify/blob/main/docs/Reference/LTS.md) for more details.
## Usage - Compress replies
This plugin adds two functionalities to Fastify: a compress utility and a global compression hook.
Currently, the following encoding tokens are supported, using the first acceptable token in this order:
1. `br`
2. `gzip`
3. `deflate`
4. `*` (no preference — `@fastify/compress` will use `gzip`)
5. `identity` (no compression)
If an unsupported encoding is received or the `'accept-encoding'` header is missing, the payload will not be compressed.
To return an error for unsupported encoding, use the `onUnsupportedEncoding` option.
The plugin compresses payloads based on `content-type`. If absent, it assumes `application/json`.
### Global hook
The global compression hook is enabled by default. To disable it, pass `{ global: false }`:
```js
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
```
Fastify encapsulation can be used to set global compression but run it only in a subset of routes by wrapping them inside a plugin.
> 🛈 Note: If using `@fastify/compress` plugin together with `@fastify/static` plugin, `@fastify/compress` must be registered (with *global hook*) **before** registering `@fastify/static`.
### Per Route options
Different compression options can be specified per route using the `compress` options in the route's configuration.
Setting `compress: false` on any route will disable compression on the route even if global compression is enabled.
```js
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
// only compress if the payload is above a certain size and use brotli
fastify.get('/custom-route', {
compress: {
inflateIfDeflated: true,
threshold: 128,
zlib: {
createBrotliCompress: () => createYourCustomBrotliCompress(),
createGzip: () => createYourCustomGzip(),
createDeflate: () => createYourCustomDeflate()
}
}, (req, reply) => {
// ...
})
```
### `reply.compress`
This plugin adds a `compress` method to `reply` that compresses a stream or string based on the `accept-encoding` header. If a JS object is passed, it will be stringified to JSON.
The `compress` method uses per-route parameters if configured, otherwise it uses global parameters.
```js
import fs from 'node:fs'
import fastify from 'fastify'
const app = fastify()
await app.register(import('@fastify/compress'), { global: false })
app.get('/', (req, reply) => {
reply
.type('text/plain')
.compress(fs.createReadStream('./package.json'))
})
await app.listen({ port: 3000 })
```
## Compress Options
### threshold
The minimum byte size for response compression. Defaults to `1024`.
```js
await fastify.register(
import('@fastify/compress'),
{ threshold: 2048 }
)
```
### customTypes
[mime-db](https://github.com/jshttp/mime-db) determines if a `content-type` should be compressed. Additional content types can be compressed via regex or a function.
```js
await fastify.register(
import('@fastify/compress'),
{ customTypes: /x-protobuf$/ }
)
```
or
```js
await fastify.register(
import('@fastify/compress'),
{ customTypes: contentType => contentType.endsWith('x-protobuf') }
)
```
### onUnsupportedEncoding
Set `onUnsupportedEncoding(encoding, request, reply)` to send a custom error response for unsupported encoding. The function can modify the reply and return a `string | Buffer | Stream | Error` payload.
```js
await fastify.register(
import('@fastify/compress'),
{
onUnsupportedEncoding: (encoding, request, reply) => {
reply.code(406)
return 'We do not support the ' + encoding + ' encoding.'
}
}
)
```
### Disable compression by header
Response compression can be disabled by an `x-no-compression` header in the request.
### Inflate pre-compressed bodies for clients that do not support compression
Optional feature to inflate pre-compressed data if the client does not include one of the supported compression types in its `accept-encoding` header.
```js
await fastify.register(
import('@fastify/compress'),
{ inflateIfDeflated: true }
)
fastify.get('/file', (req, reply) =>
// will inflate the file on the way out for clients
// that indicate they do not support compression
reply.send(fs.createReadStream('./file.gz')))
```
### Customize encoding priority
By default, `@fastify/compress` prioritizes compression as described [here](#usage). Change this by passing an array of compression tokens to the `encodings` option:
```js
await fastify.register(
import('@fastify/compress'),
// Only support gzip and deflate, and prefer deflate to gzip
{ encodings: ['deflate', 'gzip'] }
)
```
### brotliOptions and zlibOptions
Compression can be tuned with `brotliOptions` and `zlibOptions`, which are passed directly to native node `zlib` methods. See [class definitions](https://nodejs.org/api/zlib.html#zlib_class_options).
```js
server.register(fastifyCompress, {
brotliOptions: {
params: {
[zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT, // useful for APIs that primarily return text
[zlib.constants.BROTLI_PARAM_QUALITY]: 4, // default is 4, max is 11, min is 0
},
},
zlibOptions: {
level: 6, // default is typically 6, max is 9, min is 0
}
});
```
### Manage `Content-Length` header removal with removeContentLengthHeader
By default, `@fastify/compress` removes the reply `Content-Length` header. Change this by setting `removeContentLengthHeader` to `false` globally or per route.
```js
// Global plugin scope
await server.register(fastifyCompress, { global: true, removeContentLengthHeader: false });
// Route-specific scope
fastify.get('/file', {
compress: { removeContentLengthHeader: false }
}, (req, reply) =>
reply.compress(fs.createReadStream('./file.gz'))
)
```
## Usage - Decompress request payloads
This plugin adds a `preParsing` hook to decompress the request payload based on the `content-encoding` request header.
Currently, the following encoding tokens are supported:
1. `br`
2. `gzip`
3. `deflate`
If an unsupported encoding or invalid payload is received, the plugin throws an error.
If the request header is missing, the plugin yields to the next hook.
### Global hook
The global request decompression hook is enabled by default. To disable it, pass `{ global: false }`:
```js
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
```
Fastify encapsulation can be used to set global decompression but run it only in a subset of routes by wrapping them inside a plugin.
### Per Route options
Specify different decompression options per route using the `decompress` options in the route's configuration.
```js
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
// Always decompress using gzip
fastify.get('/custom-route', {
decompress: {
forceRequestEncoding: 'gzip',
zlib: {
createBrotliDecompress: () => createYourCustomBrotliDecompress(),
createGunzip: () => createYourCustomGunzip(),
createInflate: () => createYourCustomInflate()
}
}
}, (req, reply) => {
// ...
})
```
### requestEncodings
By default, `@fastify/compress` accepts all encodings specified [here](#usage). Change this by passing an array of compression tokens to the `requestEncodings` option:
```js
await fastify.register(
import('@fastify/compress'),
// Only support gzip
{ requestEncodings: ['gzip'] }
)
```
### forceRequestEncoding
By default, `@fastify/compress` chooses the decompression algorithm based on the `content-encoding` header.
One algorithm can be forced, and the header ignored, by providing the `forceRequestEncoding` option.
If the request payload is not compressed, `@fastify/compress` will try to decompress, resulting in an error.
### onUnsupportedRequestEncoding
The response error can be customized for unsupported request payload encoding by setting `onUnsupportedEncoding(request, encoding)` to a function that returns an error.
```js
await fastify.register(
import('@fastify/compress'),
{
 onUnsupportedRequestEncoding: (request, encoding) => {
return {
statusCode: 415,
code: 'UNSUPPORTED',
error: 'Unsupported Media Type',
message: 'We do not support the ' + encoding + ' encoding.'
}
}
}
)
```
### onInvalidRequestPayload
The response error can be customized for undetectable request payloads by setting `onInvalidRequestPayload(request, encoding)` to a function that returns an error.
```js
await fastify.register(
import('@fastify/compress'),
{
onInvalidRequestPayload: (request, encoding, error) => {
return {
statusCode: 400,
code: 'BAD_REQUEST',
error: 'Bad Request',
message: 'This is not a valid ' + encoding + ' encoded payload: ' + error.message
}
}
}
)
```
## Acknowledgments
Past sponsors:
- [LetzDoIt](http://www.letzdoitapp.com/)
## License
Licensed under [MIT](./LICENSE).