sharp/docs/install.md

# Installation

```sh
npm install sharp
```

```sh
yarn add sharp
```

```sh
pnpm add sharp
```

## Prerequisites

* Node.js >= 18.17.0

## Prebuilt binaries

Ready-compiled sharp and libvips binaries are provided for use on the most common platforms:

* macOS x64 (>= 10.13)
* macOS ARM64
* Linux x64 (glibc >= 2.26, musl >= 1.2.2, CPU with SSE4.2)
* Linux ARM64 (glibc >= 2.26, musl >= 1.2.2)
* Linux ARM (glibc >= 2.28)
* Windows x64
* Windows x86

This provides support for the
JPEG, PNG, WebP, AVIF (limited to 8-bit depth), TIFF, GIF and SVG (input) image formats.

## Custom libvips

To use a custom, globally-installed version of libvips instead of the provided binaries,
make sure it is at least the version listed under `engines.libvips` in the `package.json` file
and that it can be located using `pkg-config --modversion vips-cpp`.

For help compiling libvips and its dependencies, please see
[building libvips from source](https://www.libvips.org/install.html#building-libvips-from-source).

The use of a globally-installed libvips is unsupported on Windows
and on macOS when running Node.js under Rosetta.

## Building from source

This module will be compiled from source at `npm install` time when:

* a globally-installed libvips is detected (set the `SHARP_IGNORE_GLOBAL_LIBVIPS` environment variable to skip this), or
* when the `npm install --build-from-source` flag is used.

Building from source requires:

* C++11 compiler
* [node-gyp](https://github.com/nodejs/node-gyp#installation) and its dependencies

If `node-gyp` cannot be found, try adding it to `devDependencies`.

For cross-compiling, the `--platform`, `--arch` and `--libc` npm flags
(or the `npm_config_platform`, `npm_config_arch` and `npm_config_libc` environment variables)
can be used to configure the target environment.

## FreeBSD

The `vips` package must be installed before `npm install` is run.

```sh
pkg install -y pkgconf vips
```

```sh
cd /usr/ports/graphics/vips/ && make install clean
```

## Linux memory allocator

The default memory allocator on most glibc-based Linux systems
(e.g. Debian, Red Hat) is unsuitable for long-running, multi-threaded
processes that involve lots of small memory allocations.

For this reason, by default, sharp will limit the use of thread-based
[concurrency](api-utility#concurrency) when the glibc allocator is
detected at runtime.

To help avoid fragmentation and improve performance on these systems,
the use of an alternative memory allocator such as
[jemalloc](https://github.com/jemalloc/jemalloc) is recommended.

Those using musl-based Linux (e.g. Alpine) and non-Linux systems are
unaffected.

## AWS Lambda

The `node_modules` directory of the
[deployment package](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-package.html)
must include binaries for either the linux-x64 or linux-arm64 platforms
depending on the chosen architecture.

When building your deployment package on a machine that differs from the target architecture,
you will need to install either `@sharpen/sharp-linux-x64` or `@sharpen/sharp-linux-arm64` package.

```sh
npm install --force @sharpen/sharp-linux-x64
```

```sh
npm install --force @sharpen/sharp-linux-arm64
```

To get the best performance select the largest memory available.
A 1536 MB function provides ~12x more CPU time than a 128 MB function.

When integrating with AWS API Gateway, ensure it is configured with the relevant
[binary media types](https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-payload-encodings.html).

## Bundlers

### webpack

Ensure sharp is excluded from bundling via the
[externals](https://webpack.js.org/configuration/externals/)
configuration.

```js
externals: {
  'sharp': 'commonjs sharp'
}
```

### esbuild

Ensure sharp is excluded from bundling via the
[external](https://esbuild.github.io/api/#external)
configuration.

```js
buildSync({
  entryPoints: ['app.js'],
  bundle: true,
  platform: 'node',
  external: ['sharp'],
})
```

```sh
esbuild app.js --bundle --platform=node --external:sharp
```

For `serverless-esbuild`, ensure platform-specific binaries are installed
via the `serverless.yml` configuration.

```yaml
custom:
  esbuild:
    external:
      - sharp
    packagerOptions:
      scripts:
        - npm install --force @sharpen/sharp-linux-x64
```

## TypeScript

TypeScript definitions are published as part of
the `sharp` package from v0.32.0.

Previously these were available via the `@types/sharp` package,
which is now deprecated.

When using Typescript, please ensure `devDependencies` includes
the `@types/node` package.

## Fonts

When creating text images or rendering SVG images that contain text elements,
`fontconfig` is used to find the relevant fonts.

On Windows and macOS systems, all system fonts are available for use.

On macOS systems using Homebrew, you may need to set the
`PANGOCAIRO_BACKEND` environment variable to a value of `fontconfig`
to ensure it is used for font discovery instead of Core Text.

On Linux systems, fonts that include the relevant
[`fontconfig` configuration](https://www.freedesktop.org/software/fontconfig/fontconfig-user.html)
when installed via package manager are available for use.

If `fontconfig` configuration is not found, the following error will occur:
```
Fontconfig error: Cannot load default config file
```

In serverless environments where there is no control over font packages,
use the `FONTCONFIG_PATH` environment variable to point to a custom location.

Embedded SVG fonts are unsupported.

## Worker threads

On some platforms, including glibc-based Linux,
the main thread must call `require('sharp')`
_before_ worker threads are created.
This is to ensure shared libraries remain loaded in memory
until after all threads are complete.

Without this, the following error may occur:
```
Module did not self-register
```

## Known conflicts

### Canvas and Windows

If both `canvas` and `sharp` modules are used in the same Windows process, the following error may occur:
```
The specified procedure could not be found.
```