$ pub outdated --json
{
  "packages": [
    {
      "package": "foo",
      "current": {
        "version": "1.2.3"
      },
      "upgradable": {
        "version": "1.3.0"
      },
      "resolvable": {
        "version": "1.3.0"
      },
      "latest": {
        "version": "1.3.0"
      }
    }
  ]
}

$ pub outdated --no-color
Dependencies  Current  Upgradable  Resolvable  Latest  
foo           *1.2.3   1.3.0       1.3.0       1.3.0   

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --no-color --up-to-date
Dependencies  Current  Upgradable  Resolvable  Latest  
foo           *1.2.3   1.3.0       1.3.0       1.3.0   

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --no-color --prereleases
Dependencies  Current  Upgradable  Resolvable  Latest  
foo           *1.2.3   1.3.0       1.3.0       1.3.0   

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --no-color --no-dev-dependencies
Dependencies  Current  Upgradable  Resolvable  Latest  
foo           *1.2.3   1.3.0       1.3.0       1.3.0   

transitive dependencies: all up-to-date

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --no-color --no-dependency-overrides
Dependencies  Current  Upgradable  Resolvable  Latest  
foo           *1.2.3   1.3.0       1.3.0       1.3.0   

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --no-color --mode=null-safety
Running in 'null safety' mode.
Showing packages where the current version doesn't fully support null safety.

Dependencies  Current  Upgradable  Resolvable  Latest  
foo           ✗1.2.3   ✗1.3.0      ✗1.3.0      ✗1.3.0  

dev_dependencies: all fully support null safety

transitive dependencies: all fully support null safety

transitive dev_dependencies: all fully support null safety

1 upgradable dependency is locked (in pubspec.lock) to an older version.
To update it, use `pub upgrade`.

$ pub outdated --json --mode=null-safety
{
  "packages": [
    {
      "package": "foo",
      "current": {
        "version": "1.2.3",
        "nullSafety": false
      },
      "upgradable": {
        "version": "1.3.0",
        "nullSafety": false
      },
      "resolvable": {
        "version": "1.3.0",
        "nullSafety": false
      },
      "latest": {
        "version": "1.3.0",
        "nullSafety": false
      }
    }
  ]
}

$ pub outdated --json --no-dev-dependencies
{
  "packages": [
    {
      "package": "foo",
      "current": {
        "version": "1.2.3"
      },
      "upgradable": {
        "version": "1.3.0"
      },
      "resolvable": {
        "version": "1.3.0"
      },
      "latest": {
        "version": "1.3.0"
      }
    }
  ]
}