Migrate from npm install to bun install

bun install is a fast, Node.js-compatible npm client. To migrate from npm install to bun install, run bun install instead of npm install.

Designed for Node.js & Bun: bun install installs a Node.js compatible node_modules folder. You can use it in place of npm install for Node.js projects without any code changes and without using Bun’s runtime.
Automatically converts package-lock.json to Bun’s bun.lock lockfile format, preserving your existing resolved dependency versions. You can secretly use bun install in place of npm install at work without anyone noticing.
.npmrc compatible: bun install reads npm registry configuration from npm’s .npmrc, so you can use the same configuration for both npm and Bun.
Hardlinks: On Windows and Linux, bun install uses hardlinks to save disk space and speed up installs.

terminal

# It only takes one command to migrate
bun i

# To add dependencies:
bun i @types/bun

# To add devDependencies:
bun i -d @types/bun

# To remove a dependency:
bun rm @types/bun

Run package.json scripts faster

Run scripts from package.json, executables from node_modules/.bin (like npx), and JavaScript/TypeScript files (like node), all with a single command.

NPM	Bun
`npm run <script>`	`bun <script>`
`npm exec <bin>`	`bun <bin>`
`node <file>`	`bun <file>`
`npx <package>`	`bunx <package>`

bun run <executable> uses the locally-installed executable.

terminal

# Run a package.json script:
bun my-script
bun run my-script

# Run an executable in node_modules/.bin:
bun my-executable # such as tsc, esbuild, etc.
bun run my-executable

# Run a JavaScript/TypeScript file:
bun ./index.ts

Workspaces? Yes.

bun install supports workspaces similarly to npm, with more features. In package.json, set "workspaces" to an array of relative paths.

package.json

{
  "name": "my-app",
  "workspaces": ["packages/*", "apps/*"]
}

Filter scripts by workspace name

In Bun, the --filter flag accepts a glob pattern and runs the command concurrently for every workspace package whose name matches it, respecting dependency order.

terminal

bun --filter 'lib-*' my-script
# instead of:
# npm run --workspace lib-foo --workspace lib-bar my-script

Update dependencies

bun update <package> updates a dependency to the latest version that satisfies the semver range in package.json.

terminal

# Update a single dependency
bun update @types/bun

# Update all dependencies
bun update

# Ignore semver, update to the latest version
bun update @types/bun --latest

# Update a dependency to a specific version
bun update @types/bun@1.3.3

# Update all dependencies to the latest versions
bun update --latest

View outdated dependencies

To view outdated dependencies, run bun outdated. It works like npm outdated, with more compact output.

terminal

bun outdated

┌────────────────────────────────────────┬─────────┬────────┬────────┐
│ Package                                │ Current │ Update │ Latest │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ @types/bun (dev)                       │ 1.1.6   │ 1.1.10 │ 1.1.10 │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ @types/react (dev)                     │ 18.3.3  │ 18.3.8 │ 18.3.8 │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ @typescript-eslint/eslint-plugin (dev) │ 7.16.1  │ 7.18.0 │ 8.6.0  │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ @typescript-eslint/parser (dev)        │ 7.16.1  │ 7.18.0 │ 8.6.0  │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ @vscode/debugadapter (dev)             │ 1.66.0  │ 1.67.0 │ 1.67.0 │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ esbuild (dev)                          │ 0.21.5  │ 0.21.5 │ 0.24.0 │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ eslint (dev)                           │ 9.7.0   │ 9.11.0 │ 9.11.0 │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ mitata (dev)                           │ 0.1.11  │ 0.1.14 │ 1.0.2  │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ prettier-plugin-organize-imports (dev) │ 4.0.0   │ 4.1.0  │ 4.1.0  │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ source-map-js (dev)                    │ 1.2.0   │ 1.2.1  │ 1.2.1  │
├────────────────────────────────────────┼─────────┼────────┼────────┤
│ typescript (dev)                       │ 5.5.3   │ 5.6.2  │ 5.6.2  │
└────────────────────────────────────────┴─────────┴────────┴────────┘

List installed packages

bun pm ls lists the packages installed in the node_modules folder, using Bun’s lockfile as the source of truth. Pass the -a flag to also list transitive dependencies.

terminal

# List top-level installed packages:
bun pm ls

my-pkg node_modules (781)
├── @types/node@20.16.5
├── @types/react@18.3.8
├── @types/react-dom@18.3.0
├── eslint@8.57.1
├── eslint-config-next@14.2.8
...

terminal

# List all installed packages:
bun pm ls -a

my-pkg node_modules
├── @alloc/quick-lru@5.2.0
├── @isaacs/cliui@8.0.2
│   └── strip-ansi@7.1.0
│       └── ansi-regex@6.1.0
├── @jridgewell/gen-mapping@0.3.5
├── @jridgewell/resolve-uri@3.1.2
...

Create a package tarball

bun pm pack creates a tarball of the package in the current directory.

terminal

# Create a tarball
bun pm pack

Total files: 46
Shasum: 2ee19b6f0c6b001358449ca0eadead703f326216
Integrity: sha512-ZV0lzWTEkGAMz[...]Gl4f8lA9sl97g==
Unpacked size: 0.41MB
Packed size: 117.50KB

Shebang

If the package references node in the #!/usr/bin/env node shebang, bun run respects it by default and uses the system’s node executable. To force it to use Bun instead, pass --bun to bun run. When you pass --bun, Bun creates a symlink to the locally-installed Bun executable named "node" in a temporary directory and adds it to your PATH for the duration of the script.

terminal

# Force using Bun's runtime instead of node
bun --bun my-script

# This also works:
bun run --bun my-script

Global installs

Install packages globally with bun i -g <package>. By default, they go into a .bun/install/global/node_modules folder inside your home directory.

terminal

# Install a package globally
bun i -g eslint

# Run a globally-installed package without the `bun run` prefix
eslint --init

Generate a yarn-compatible lockfile

Configure git to diff Bun's lockb lockfile

Overview

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Migrate from npm install to bun install

Run package.json scripts faster

Workspaces? Yes.

Filter scripts by workspace name

Update dependencies

View outdated dependencies

List installed packages

Create a package tarball

Shebang

Global installs

​Run package.json scripts faster

​Workspaces? Yes.

​Filter scripts by workspace name

​Update dependencies

​View outdated dependencies

​List installed packages

​Create a package tarball

​Shebang

​Global installs

Run package.json scripts faster

Workspaces? Yes.

Filter scripts by workspace name

Update dependencies

View outdated dependencies

List installed packages

Create a package tarball

Shebang

Global installs