npm update [-g] [<pkg>...] aliases: up, upgrade
This command will update all the packages listed to the latest version (specified by the tag config), respecting semver.
It will also install missing packages. As with all commands that install packages, the --dev flag will cause devDependencies to be processed as well.
If the -g flag is specified, this command will update globally installed packages.
If no package name is specified, all packages in the specified location (global or local) will be updated.
As of npm@2.6.1, the npm update will only inspect top-level packages. Prior versions of npm would also recursively inspect all dependencies. To get the old behavior, use npm --depth 9999 update.
IMPORTANT VERSION NOTE: these examples assume npm@2.6.1 or later. For older versions of npm, you must specify --depth 0 to get the behavior described below.
For the examples below, assume that the current package is app and it depends on dependencies, dep1 (dep2, .. etc.). The published versions of dep1 are:
{
"dist-tags": { "latest": "1.2.2" },
"versions": [
"1.2.2",
"1.2.1",
"1.2.0",
"1.1.2",
"1.1.1",
"1.0.0",
"0.4.1",
"0.4.0",
"0.2.0"
]
}
If app's package.json contains:
"dependencies": {
"dep1": "^1.1.1"
}
Then npm update will install dep1@1.2.2, because 1.2.2 is latest and 1.2.2 satisfies ^1.1.1.
However, if app's package.json contains:
"dependencies": {
"dep1": "~1.1.1"
}
In this case, running npm update will install dep1@1.1.2. Even though the latest tag points to 1.2.2, this version does not satisfy ~1.1.1, which is equivalent to >=1.1.1 <1.2.0. So the highest-sorting version that satisfies ~1.1.1 is used, which is 1.1.2.
Suppose app has a caret dependency on a version below 1.0.0, for example:
"dependencies": {
"dep1": "^0.2.0"
}
npm update will install dep1@0.2.0, because there are no other versions which satisfy ^0.2.0.
If the dependence were on ^0.4.0:
"dependencies": {
"dep1": "^0.4.0"
}
Then npm update will install dep1@0.4.1, because that is the highest-sorting version that satisfies ^0.4.0 (>= 0.4.0 <0.5.0)
When you want to update a package and save the new version as the minimum required dependency in package.json, you can use npm update -S or npm update --save. For example if package.json contains:
"dependencies": {
"dep1": "^1.1.1"
}
Then npm update --save will install dep1@1.2.2 (i.e., latest), and package.json will be modified:
"dependencies": {
"dep1": "^1.2.2"
}
Note that npm will only write an updated version to package.json if it installs a new package.
npm update -g will apply the update action to each globally installed package that is outdated -- that is, has a version that is different from latest.
NOTE: If a package has been upgraded to a version newer than latest, it will be downgraded.