$ pub outdated --json
{
  "packages": [
    {
      "package": "foo",
      "current": {
        "version": "1.0.0-dev.1"
      },
      "upgradable": {
        "version": "1.0.0-dev.1"
      },
      "resolvable": {
        "version": "0.9.0"
      },
      "latest": {
        "version": "0.9.0"
      }
    },
    {
      "package": "mop",
      "current": {
        "version": "0.10.0-dev"
      },
      "upgradable": {
        "version": "0.10.0-dev"
      },
      "resolvable": {
        "version": "0.10.0"
      },
      "latest": {
        "version": "1.0.0-dev"
      }
    }
  ]
}

$ pub outdated --no-color
Dependencies  Current       Upgradable    Resolvable  Latest     
foo           *1.0.0-dev.1  *1.0.0-dev.1  0.9.0       0.9.0      
mop           *0.10.0-dev   *0.10.0-dev   *0.10.0     1.0.0-dev  

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ pub outdated --no-color --up-to-date
Dependencies  Current       Upgradable    Resolvable  Latest     
bar           0.9.0         0.9.0         0.9.0       0.9.0      
foo           *1.0.0-dev.1  *1.0.0-dev.1  0.9.0       0.9.0      
mop           *0.10.0-dev   *0.10.0-dev   *0.10.0     1.0.0-dev  

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ pub outdated --no-color --prereleases
Dependencies  Current       Upgradable    Resolvable  Latest       
bar           *0.9.0        *0.9.0        *0.9.0      1.0.0-dev.2  
foo           *1.0.0-dev.1  *1.0.0-dev.1  *0.9.0      1.0.0-dev.2  
mop           *0.10.0-dev   *0.10.0-dev   *0.10.0     1.0.0-dev    

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ pub outdated --no-color --no-dev-dependencies
Dependencies  Current       Upgradable    Resolvable  Latest     
foo           *1.0.0-dev.1  *1.0.0-dev.1  0.9.0       0.9.0      
mop           *0.10.0-dev   *0.10.0-dev   *0.10.0     1.0.0-dev  

transitive dependencies: all up-to-date

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ pub outdated --no-color --no-dependency-overrides
Dependencies  Current       Upgradable    Resolvable  Latest     
foo           *1.0.0-dev.1  *1.0.0-dev.1  0.9.0       0.9.0      
mop           *0.10.0-dev   *0.10.0-dev   *0.10.0     1.0.0-dev  

dev_dependencies: all up-to-date

transitive dependencies: all up-to-date

transitive dev_dependencies: all up-to-date

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ 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      
bar           ✗0.9.0        ✗0.9.0        ✗0.9.0      ✗0.9.0      
foo           ✗1.0.0-dev.1  ✗1.0.0-dev.1  ✗0.9.0      ✗0.9.0      
mop           ✗0.10.0-dev   ✗0.10.0-dev   ✗0.10.0     ✗1.0.0-dev  

dev_dependencies: all fully support null safety

transitive dependencies: all fully support null safety

transitive dev_dependencies: all fully support null safety

2  dependencies are constrained to versions that are older than a resolvable version.
To update these dependencies, edit pubspec.yaml.

$ pub outdated --json --mode=null-safety
{
  "packages": [
    {
      "package": "bar",
      "current": {
        "version": "0.9.0",
        "nullSafety": false
      },
      "upgradable": {
        "version": "0.9.0",
        "nullSafety": false
      },
      "resolvable": {
        "version": "0.9.0",
        "nullSafety": false
      },
      "latest": {
        "version": "0.9.0",
        "nullSafety": false
      }
    },
    {
      "package": "foo",
      "current": {
        "version": "1.0.0-dev.1",
        "nullSafety": false
      },
      "upgradable": {
        "version": "1.0.0-dev.1",
        "nullSafety": false
      },
      "resolvable": {
        "version": "0.9.0",
        "nullSafety": false
      },
      "latest": {
        "version": "0.9.0",
        "nullSafety": false
      }
    },
    {
      "package": "mop",
      "current": {
        "version": "0.10.0-dev",
        "nullSafety": false
      },
      "upgradable": {
        "version": "0.10.0-dev",
        "nullSafety": false
      },
      "resolvable": {
        "version": "0.10.0",
        "nullSafety": false
      },
      "latest": {
        "version": "1.0.0-dev",
        "nullSafety": false
      }
    }
  ]
}