Awesome
@fastify/compress
Adds compression utils to the Fastify reply
object and a hook to decompress requests payloads.
Supports gzip
, deflate
, and brotli
.
Important note: since
@fastify/compress
version 4.x payloads that are compressed using thezip
algorithm are not automatically uncompressed anymore.@fastify/compress
main feature is to provide response compression mechanism to your server, however thezip
format does not appear in the IANA maintained Table of Content Encodings and thus such behavior was out of the scope of this plugin.
Install
npm i @fastify/compress
Compatibility
Plugin version | Fastify version |
---|---|
^8.x | ^5.x |
^6.x | ^4.x |
^3.x | ^3.x |
^2.x | ^2.x |
^0.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 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:
br
gzip
deflate
*
(no preference —@fastify/compress
will usegzip
)identity
(no compression)
If an unsupported encoding is received or if the 'accept-encoding'
header is missing, it will not compress the payload. If an unsupported encoding is received and you would like to return an error, provide an onUnsupportedEncoding
option.
The plugin automatically decides if a payload should be compressed based on its content-type
; if no content type is present, it will assume application/json
.
Global hook
The global compression hook is enabled by default. To disable it, pass the option { global: false }
:
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
Remember that thanks to the Fastify encapsulation model, you can set a global compression, but run it only in a subset of routes if you wrap them inside a plugin.
Important note! If you are using @fastify/compress
plugin together with @fastify/static
plugin, you must register the @fastify/compress
(with global hook) before registering @fastify/static
.
Per Route options
You can specify different options for compression per route by passing in the compress
options on the route's configuration.
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) => {
// ...
})
Note: Setting compress = false
on any route will disable compression on the route even if global compression is enabled.
reply.compress
This plugin adds a compress
method to reply
that accepts a stream or a string, and compresses it based on the accept-encoding
header. If a JS object is passed in, it will be stringified to JSON.
Note that the compress method is configured with either the per route parameters if the route has a custom configuration or with the global parameters if the the route has no custom parameters but
the plugin was defined as global.
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 a response to be compressed. Defaults to 1024
.
await fastify.register(
import('@fastify/compress'),
{ threshold: 2048 }
)
customTypes
mime-db is used to determine if a content-type
should be compressed. You can compress additional content types via regular expression or by providing a function.
await fastify.register(
import('@fastify/compress'),
{ customTypes: /x-protobuf$/ }
)
or
await fastify.register(
import('@fastify/compress'),
{ customTypes: contentType => contentType.endsWith('x-protobuf') }
)
onUnsupportedEncoding
When the encoding is not supported, a custom error response can be sent in place of the uncompressed payload by setting the onUnsupportedEncoding(encoding, request, reply)
option to be a function that can modify the reply and return a string | Buffer | Stream | Error
payload.
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
You can selectively disable response compression by using the 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.
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 at the beginning of §Usage - Compress replies. You can change that by passing an array of compression tokens to the encodings
option:
await fastify.register(
import('@fastify/compress'),
// Only support gzip and deflate, and prefer deflate to gzip
{ encodings: ['deflate', 'gzip'] }
)
brotliOptions and zlibOptions
You can tune compression by setting the brotliOptions
and zlibOptions
properties. These properties are passed directly to native node zlib
methods, so they should match the corresponding class definitions.
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. You can change that by setting the removeContentLengthHeader
to false
either on a global scope or on a route specific scope.
// 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 that decompress the request payload according to the content-encoding
request header.
Currently, the following encoding tokens are supported:
br
gzip
deflate
If an unsupported encoding or and invalid payload is received, the plugin will throw an error.
If the request header is missing, the plugin will not do anything and yield to the next hook.
Global hook
The global request decompression hook is enabled by default. To disable it, pass the option { global: false }
:
await fastify.register(
import('@fastify/compress'),
{ global: false }
)
Remember that thanks to the Fastify encapsulation model, you can set a global decompression, but run it only in a subset of routes if you wrap them inside a plugin.
Per Route options
You can specify different options for decompression per route by passing in the decompress
options on the route's configuration.
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 at the beginning of §Usage - Decompress request payloads. You can change that by passing an array of compression tokens to the requestEncodings
option:
await fastify.register(
import('@fastify/compress'),
// Only support gzip
{ requestEncodings: ['gzip'] }
)
forceRequestEncoding
By default, @fastify/compress
chooses the decompressing algorithm by looking at the content-encoding
header, if present.
You can force one algorithm and ignore the header at all by providing the forceRequestEncoding
option.
Note that if the request payload is not compressed, @fastify/compress
will try to decompress, resulting in an error.
onUnsupportedRequestEncoding
When the request payload encoding is not supported, you can customize the response error by setting the onUnsupportedEncoding(request, encoding)
option to be a function that returns an error.
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
When the request payload cannot be decompressed using the detected algorithm, you can customize the response error setting the onInvalidRequestPayload(request, encoding)
option to be a function that returns an error.
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
}
}
}
)
Note
Please note that in large-scale scenarios, you should use a proxy like Nginx to handle response compression.
Acknowledgements
Past sponsors:
License
Licensed under MIT.