Minecraft launcher

Minecraft launcher

Current version	2.1.1143
Platforms

The Minecraft launcher is the login and downloader front-end to the stand-alone client. It is responsible for downloading the main Java packages, including minecraft.jar, which holds the code and resources of the game such as textures, and LWJGL. It also acts somewhat like a basic and easily bypassable copy-restriction by forcing the user to login to a paid account when running for the first time. It is possible to use the launcher to run versions of Minecraft from nearly any era, however some versions are still not included on the launcher, such as release version 1.5, any versions of Indev, joke versions such as 2.0 and any of the Beta 1.9 Prereleases, even though some of these versions remain available on Mojang's legacy download servers. The current launcher is the sixth launcher for Minecraft, and the second that was built to automatically update itself.

Launch

The login screen for launchers without previously logged-in users.

Every time the launcher is executed, it checks a specific directory where Minecraft stores its files called ".minecraft". It checks a file called "launcher_profiles.json" for login credentials. If the file does not exist, is corrupt, or no user is logged in, the user must login with a valid premium account, otherwise the user will be directed to play the Demo version or purchase the game.

When logging in, the launcher will first try to verify the login. If a valid "launcher_profiles.json" file exists but there is no Internet connection, the launcher will offer a "Play offline" mode if a player was logged in when it was last closed. If the connection is successful, the launcher will then, depending on profile options, compare the latest version in the latest "versions" directory to the latest version reported by the server. If the selected version does not exist or the latest installed version is outdated when "Use latest version" is selected in the profile, the launcher will download all Minecraft components and Java binary files. It will also synchronize everything in the "assets" folder (see Resource pack).

Finally, upon a successful update or installation, the launcher will execute the Minecraft jar (via "javaw.exe", Oracle's Java Virtual Machine executable.) It is possible however for there to be missing ".jar" files, in which case the launcher will attempt to replace the missing files automatically but will stop if there is no connection.

Currently, the Minecraft launcher supports 57 languages.

Features

Launcher

• Manage multiple profiles (stored in "launcher_profiles.json"). Each profile can control:
  • Game version. Includes access to outdated development builds and previous releases. You can also add older/custom versions manually.
  • Mojang account used to play the game
  • Command line arguments for Java (such as heap size)
  • Game Directory (where the game files are saved on disk)
  • Edit profile pictures or custom made ones
• The launcher doesn't store your password locally. Instead of this, it uses a 'refresh token'
• The launcher supports multiple instances (as the game also does)
• Automatic updates for launcher
• Ability to update libraries, such as LWJGL
• Offline mode. (The first time launch requires an Internet connection to download required resources)
• 57 Languages avaliable
• Crashes can be reported to Mojang, through Hopper
• Crashes are indexed through a database for information on how to fix the issue
• Launcher Settings
• Switching Accounts or logging off
• Changing Skins
• Downloads servers on versions
• Help button
• Shows you the launcher version information when you click the launcher version

Backward Compatibility

A profile with Alpha and Beta versions enabled

The Minecraft launcher has the ability to play old Alpha and Beta versions of the game. Currently, snapshots, Alpha, Beta, and all Release versions are available to play. Four Pre-classic versions, four Classic versions, and one Infdev version are already added under the names "old-alpha version". No Indev versions are currently available from the launcher.

To enable the old versions either click the "Launch Options" then turn the "Historical Versions" on then open your profile or make a new one, next select any of Alpha/Beta versions on the Version box then click "Save" button.

However, these versions are very out of date and may be unstable. Any bugs, glitches, missing features, or crashes that result from instability will never be resolved as only later versions are supported. Mojang strongly recommends that you play them in separate directories than your other saves to avoid corruption.

Skins

Skin options in the launcher

You can change or add your custom skin within the Minecraft launcher. To change or add your skin click the "Skins" button, then click the "Browse" button to navigate through your file system for your skin file. The file must have a resolution of 64×64 in order for the launcher to accept it as a skin file. Additionally, the skin file must be in a .png format. After you have found the skin file, click the "Save" button to confirm your in-game skin.

• You can reset your skin to the Steve or Alex defaults by clicking "Click to reset".
• You can choose between player models - either Classic (Steve) or Slim (Alex).

If the game is running when the user enters this menu, a warning appears at the bottom of the launcher: Minecraft is currently running. Skin changes may not take effect until the game is next started.

Profiles

When you open the launcher for first time, it creates a profile that selects the latest version of Minecraft - it cannot be removed.

However, you may create a game profile of your own in the launcher. Click on the "Launch Options" button, then click "Add New" to create one. After this, name your profile as you want it. If you leave it, it will be named "Unnamed Configuration". Then, optionally, select a profile picture from the launcher or a custom one. However, it must be a 128×128 .png picture. Select the version you wish to play, and click "Save" to confirm your profile. If you want to edit a profile, just click it. The same applies if you wish to delete a profile. Simply click the profile you want to delete and then click the "Delete [X]" button to remove it.

• 

  Profile settings in the launcher
  You can download server versions by clicking "Download Server".
• If you want to resize the game, turn "Resolution" on to change the game window size.
• You can turn "Advanced Settings" on to show more profile options.
• If you want to change the .minecraft file path, turn the on the "Game directory" option. Now, navigate to the folder where you wish to relocate the .minecraft folder. You can also open the Minecraft profile by clicking the green arrow-shaped "Go to folder" button.
• If you turned "Snapshot Versions" on, it creates a "Latest Snapshot" profile automatically.
• You can manually set a logging configuration (see the Debugging article on wiki.vg for more info)

Command Line usage

As of 2.0.1003, the launcher has 9 command-line options available:

• --clean - This option deletes the game and runtime folders, including their contents, from the working directory.
• --launcherui
• --workDir - This option, followed by a path (relative or absolute), will change the location (and/or name) of the .minecraft folder.
• --nativeLauncherVersion
• --tmpDir - This option, followed by a path (relative or absolute), will change the location (and/or name) of the tmp folder.
• --lockDir
• --winTen - This option adds support for Windows 10. Since the launcher now supports Windows 10 fully, this option is unnecessary and seems to have no effect.
• --proxyHost
• --proxyPort

The --workDir option can be used to create a portable installation of the game. For example, --workDir . can be used to make the launcher use the current directory (no matter what your current folder is called).

History

Alpha
v1.0.0					Initial release. In this version users can choose not only the current version but also Infdev.
					The client requires an internet connection on the first run and for updates, but after that the game supports playing offline.
					Command line arguments are accepted to launch the game. Using the format java -cp Minecraft.jar net.minecraft.LauncherFrame username password will allow login without joining a server, while the format java -cp minecraft.jar net.minecraft.LauncherFrame username password serveraddress:portnumber allows joining a server.
v1.2.2					Command line arguments format changed.
Beta
1.3					Released in February 21, 2011. A technical sneak preview was published by Notch on February 18, 2011.Added capability of automatic login to the game and/or server by command line arguments.
					Added smarter update system that only updates changed files, prompts the user to update, allows HTTPS logins for a more secure connection, and offers general UI improvements.
					Link to the Minecraft install directory for easy access.
					Add Force Update button under the Options dialog.
					The launcher also featured an inline "changelog" via a Tumblr called MCUpdate, and supports command-line arguments.
					Added the new Minecraft logo.
					Added official links, community links and Mojang on Twitter links.
Official release
1.2.1					Properly selects 64-bit Java installations for Mac OS X users.
1.3.2					Added ability to launch demo mode for non-premium users.
1.6.1			13w16a		New launcher added. See launcher history below.

Minecraft Launcher

Launcher version	Release date	Summary of changes
2.1.1144 (Mac OS)	June 21, 2018	Fixed MCL-9319: "Launcher crashes after staying on and exiting the game" Other unknown changes
2.1.1143 (Windows)	June 21, 2018	Fixed MCL-9319: "Launcher crashes after staying on and exiting the game" Other unknown changes
2.0.1051 (Windows)	May 8, 2018	Unknown
2.0.1049 (Windows)	May 8, 2018	Unknown
1.6.89-j	May 8, 2018	Unknown
1.6.84-j	October 26, 2017	Unknown
2.0.1007-stage (macOS)	October 25, 2017	Unknown
2.0.1006-stage (Windows)	October 25, 2017	Unknown
2.0.1005 (Linux)	October 25, 2017	Support for arguments block instead of minecraftArguments template string in the version JSON
2.0.1004 (macOS)	October 25, 2017	Support for arguments block instead of minecraftArguments template string in the version JSON
2.0.1003	October 25, 2017	Fixed launching modded versions
1.6.82-j	October 25, 2017	Support for arguments block instead of minecraftArguments template string in the version JSON
2.0.995	October 25, 2017	Support for arguments block instead of minecraftArguments template string in the version JSON
1.6.81-stage	October 25, 2017	Unknown
1.6.79-stage	June 13, 2017	Unknown
2.0.935 (macOS)	June 13, 2017	Unknown
2.0.934	June 13, 2017	Unknown
2.0.932-stage	June 13, 2017	Unknown
2.0.895	May 30, 2017	New translations and a fix for those stuck/crashing on "Preparing...".
2.0.847	April 10, 2017	Unknown
2.0.834 (macOS)	March 10, 2017	Unknown
2.0.833	March 10, 2017	Unknown
2.0.806	February 9, 2017	Unknown
2.0.774-stage	February 8, 2017	Unknown
2.0.760-stage	February 3, 2017	Unknown
2.0.757-stage	February 3, 2017	Unknown
2.0.726-stage	February 1, 2017	Fixed some issues with the update process.
2.0.710-stage	January 31, 2017	Fixed some issues with mods.
2.0.700-stage	January 31, 2017	Unknown
2.0.673-stage	January 27, 2017	Unknown
1.6.73-j	January 26, 2017	Unknown
2.0.663-stage	January 25, 2017	No security popups for Mac anymore.
2.0.581-stage	January 18, 2017	Added a launcher version information tab, support for Linux.
2.0.580-stage (macOS)	January 18, 2017	Added a launcher version information tab.
2.0.511-stage (macOS)	January 3, 2017	Changed font from the Minecraft default to Segoe UI.
2.0.510-stage	January 3, 2017	Changed font from the Minecraft default to Segoe UI. Fixed a bug where the resolution was 2304×1202 regardless of launch option or window size.
2.0.497-stage	December 29, 2016	Added more languages.
2.0.490-stage	December 27, 2016	Unknown
2.0.465-stage (macOS)	December 8, 2016	Unknown
2.0.464-stage	December 8, 2016	Unknown
2.0.455-stage	December 7, 2016	Unknown
2.0.447-stage	December 6, 2016	Fixed a crash when you launched any minecraft.jar except for "1.11 Latest release" or lower.[citation needed]
2.0.429-stage	December 1, 2016	Unknown
2.0.425-stage	November 30, 2016	Unknown
2.0.24-stage	November 29, 2016	Unknown
2.0.414-stage	November 28, 2016	Fixed a bug where the Launcher could get stuck on 'Loading...' everywhere.
2.0.387-stage	November 25, 2016	Added language selection
1.6.70	November 17, 2016	Unknown
2.0.320-stage	November 4, 2016	Unknown
2.0.282-stage	November 2, 2016	Now supports running multiple instances of Minecraft at the same time Can now be kept open while the game is running Now backs ups "launcher_profiles.json" before migrating settings to new launcher Made launch options slightly smaller The button to add a new launch option is now at the top of the list "Keep launcher open" and "Show game log" are now separate settings Multiple bug fixes: Fixed running modded versions Resolution setting should now work properly Fixed an issue where opening the game directory would give an error message even when it worked Pressing Del in input fields no longer removes the rest of the line Pressing Tab ↹ on the news page no longer messes with the news carousel Fixed a crash that sometimes happened when the game closed Selecting input with your mouse and hitting backspace on the keyboard should now properly delete the input The version information page no longer selects all text when you click it
1.6.69	October 26, 2016	Unknown
2.0.164-stage	October 26, 2016	New launcher iteration for testing initially for Windows and macOS Runs as a native application that no longer requires Java Interface redesign
1.6.66	October 24, 2016	Now warns the player when their profile has been opened in the new launcher.
1.6.61	March 3rd, 2016	Game Session ID is now hidden in the game output tab when launching the game, now says Session ID is <censored>
1.6.59	February 25, 2016	Unknown
1.6.57	February 24, 2016	Unknown
1.6.51	February 4, 2016	Unknown
1.6.48	October 9, 2015	Unknown
1.6.44	September 11, 2015	Added information about new OSX Installer. (Showing only on OSX)
1.6.39	September 8, 2015	Fixed Launcher window closing. Fixed closing the "Profile Editor" window. Minor changes.
1.6.19	July 24, 2015	Added Windows 10 support Added new argument -winTen
1.6.13	July 1, 2015	Launcher now creating folder "server-resource-packs" in game directory.
1.6.11	January 30, 2015	Installer uses Java 8 Executable downloads its own runtime; Java no longer needs to be installed Bug fixes: MCL-546 – Unknown publisher, missing digital signature MCL-2987 – Launcher will not remember login info by your gamertag MCL-3128 – Launcher stuck on launcher.pack.lzma download MCL-3303 – Launcher doesn't open.
1.6.5	December 18, 2014	Test launcher Launcher Log takes note of 'proxy', for instance showing 'proxy == DIRECT' Fixed: MCL-3287 – "unknown error" when running Minecraft.msi
1.6.3	December 17, 2014	Test launcher Launcher for Windows now available as .msi, installs to the /Program Files (x86)/Minecraft directory First installable launcher.
1.5.5	December 16, 2014	Test launcher Unknown
1.5.4	December 12, 2014	Test launcher Update for the native bootstrap Uses a local, launcher-managed Java runtime instead of system Java.
1.5.3	September 1, 2014	Bug fixes: MCL-2300 – Extra Fonts installed in Windows 8.1 stops Launcher running MCL-3013 – Launcher: "Playing offline" MCL-3171 – Checksum mismatch for realms 1.5.8 MCL-3257 – < Forgotten in the Client
1.5.2	August 19, 2014	Re-launching Minecraft with a user used previously will override the game output tab for that user
1.5.1	July 29, 2014	Fix launcher stuck on Loading... Fixed: MCL-2494 – Play and Log out buttons grayed out on first run of launcher / launcher update
1.5	July 28, 2014	Development Console tab renamed to Launcher Log You can now run multiple instances of Minecraft at once, provided they're on different users Play button renamed to Already Playing... if Minecraft is open while looking at launcher New tab called Game Output (yourusername) appears after launching minecraft
1.4.7	July 25, 2014	Prepend libraries instead of appending(?)
1.4.6	July 25, 2014	Added some command-line switches on the Profile Editor(?) Added version inheritance
1.4.5	July 25, 2014	Added a "Switch users" button to make switching users easier Another attempt to fix MCL-2494, but the fix didn't work.
1.4.4	May 19, 2014	Attempt to fix MCL-2494, but the fix didn't work. Fixed: MCL-2564 – No alpha or Beta versions in launcher (even local ones)
1.4.2	May 2, 2014	Loading bar displays file currently being downloaded Fixed: MCL-2350 – Slowly eats large amounts of heap Removed tab Local Version Editor (NYI) Auto cleanup unused libraries
1.3.11	March 12, 2014	Update Notes website frame uses JavaFX if available Profiles are now displayed in alphabetical order
1.3.10	February 13, 2014	Libraries use SHA-1 for validation
1.3.9	January 24, 2014	Updated bug tracker links
1.3.8	January 8, 2014	Added "(Why can I only play demo?)" link for demo accounts, under the "play demo" button. The link redirects you here
1.3.7	December 12, 2013	Unknown
1.3.6	December 5, 2013	Fixed: MCL-1895 – Cannot play offline in 1.3.5 version - immediately gamecrash when launching
1.3.5	December 4, 2013	Rearranged the assets folder for the new Assets Management System.
1.3.4	November 26, 2013	Faster downloading of some big files.
1.3.3	November 20, 2013	(Possible) Bridging of Mojang and Twitch accounts.
1.3.2	November 18, 2013	Added time it took to finish jobs. Faster resource downloading.
1.3.1	October 29, 2013	Speed improvements Basic read-only popup on version list tab Misc fixes and cleanups
1.2.8	October 25, 2013	Unknown
1.2.7	October 18, 2013	Added an open game directory button in the profile editor.
1.2.5	September 23, 2013	No longer displays the developer console automatically after clicking "Play". (MCL-1266)
1.2.4	September 19, 2013	Unknown
1.2.3	September 12, 2013	You can now log out from everywhere with the launcher (MCL-1270)
1.2.2	September 3, 2013	Fixed a bug (MCL-1461) that made the launcher take a long time to load up.
1.2.1 (Files uploaded)	August 6, 2013	5 old Minecraft versions from Classic and Pre-classic have been pushed to the launcher.
1.2.1 (Files uploaded)	August 6, 2013	Added Alpha versions
1.2.1	August 2, 2013	Added a warning about using Beta, Alpha, and snapshot versions
1.2	August 1, 2013	Added a "Time Machine" feature to use Beta versions. An option for Alpha has been included but the versions are not available yet. Also allows players to play versions 1.2.5-1.4.7
1.1.4	July 31, 2013	Some small text updates
1.1.3	July 27, 2013	Fixed low FPS issues on Intel HDXXXX chipsets.
1.1.2	July 22, 2013	Fixed MCL-1241 - Cannot play offline in 1.1.1
1.1.1	July 19, 2013	New-look launcher and login screen Launcher now closes automatically when game window opens
1.0.10	July 12, 2013	Further support for Hopper Client crashes can be flagged as Public Nothing is currently done with these Profiles have the option to disable Hopper support Reporting directly to the bug tracker is only allowed if Hopper is turned off or the launcher can't connect to Hopper Hopper will not send crash report to bug tracker if the game is modded
1.0.9	July 10, 2013	Added support for the new crash-reporting system, Hopper Any client crash will automatically submit the crash report
1.0.8 OS X (Re-upload)	July 9, 2013	Fixes to the launcher having trouble playing 1.6.2 on OS X 10.5.8 (Leopard)
1.0.8 OS X (Re-upload)	July 8, 2013	Fixes to the launcher having trouble playing 1.6.2 on OS X 10.5.8 (Leopard)
1.0.8	July 2, 2013	The launcher now has a high-definition icon[citation needed] Mac OS X 10.5.8 users have had Minecraft 1.6.1 disabled pending a LWJGL fix, however 1.5.2 is not affected
1.0.7	July 2, 2013	Added ability to disable automatic login
1.0.6	July 1, 2013	Bug fixes: MCL-92 – Starting Window Size does not fit entire GUI MCL-227 – Play button not in frame @ Linux MCL-262 – Text does not fit in window MCL-287 – Launcher gui has limited visuals, can't select version - no access to tabs MCL-596 – Incorrect version in new Mac launcher MCL-696 – I don't see an option to change RAM in "Edit Profile"
1.0.5	July 1, 2013	Added a 'snapshot' setting in the profile editor, enabling/disabling snapshots. 'Minecraft.exe'(launcher) has been digitally signed. (MCL-546)
1.0.4	June 28, 2013	Added a 'resolution' setting in the profile editor.
1.0.3	June 27, 2013	Bug fixes: MCL-587 – Full game can be played with non-premium account MCL-600 – Launcher gives wrong message when you sign in with username instead of email.
1.0.2	June 27, 2013	Unknown
1.0.1	June 26, 2013	Yggdrasil authentication re-deployed Fixed: MCL-568 – Migrated Account - Can't login in 1.6 prerelease on 1.0.1 launcher
1.0.0	June 26, 2013	Launcher downgraded to 1.0.0 Disabled Yggdrasil because of login error
1.0.1	June 26, 2013	Enabled Yggdrasil, The new auth system More secure and much more featureful.
1.0	June 25, 2013	Unknown
0.9.5	June 18, 2013	Unknown
0.9.4	June 18, 2013	Added "New Profile" and "Edit Profile" Buttons to the profile selection panel
0.9.3	June 14, 2013	Unknown
0.9.2	June 13, 2013	Unknown
0.9.1	June 10, 2013	Fixed: MCL-412 – OS X: Exception in thread "main" java.lang.NoClassDefFoundError: net/minecraft/client/main/Main
0.9	June 10, 2013	Now includes a Profile Editor tab. Choosing the game's version can only be done by double clicking your profile and changing the version in the drop down list. Changes to the Version Selector area.
0.8.3	June 7, 2013	Unknown
0.8.2	May 27, 2013	Unknown
0.8.1	May 21, 2013	Client window now uses Crafting Table icon for main window when a snapshot build is selected; Launcher window still uses Grass Block icon Selecting release builds on Windows currently uses the basic Java icon
0.8	May 20, 2013	Unknown
0.7.2	May 15, 2013	Unknown
0.7	May 13, 2013	Launcher downgraded to 0.7
0.7.1	May 4, 2013	Unknown
0.7	May 2, 2013	Unknown
0.6	April 25, 2013	Unknown
0.5	April 23, 2013	Added 1.5.1 to the list of available versions in the launcher
0.4	April 23, 2013	Re-enabled crash reporting
0.3	April 22, 2013	Added Local Version Editor (NYI) tab to the launcher Added window to check server status Small bug fixes
0.2	April 19, 2013	Added Development Console tab to the launcher Fixed starting game trouble
0.1	April 18, 2013	.minecraft directory structure is changed: "assets" folder; stores resources such as language packs and sounds. All music discs now use .ogg format instead of .mus format. "library" folder; stores Java libraries such as LWJGL and jinput.jar. "versions" folder; there are file "versions.json" (meta data) and folders that stores minecraft.jar for each versions (but its name is same as its version. e.g. for 13w16a, "versions/13w16a/13w16a.jar"). The launcher is an executable.

Gallery

• 

  The first Minecraft launcher.

• 

  The second Minecraft launcher. You can see old Minecraft logo.

• 

  The third Minecraft launcher.

• 

  The fourth Minecraft launcher.

• 

  The fifth Minecraft launcher version 1.6.

• 

  The sixth and current Minecraft launcher version 2.0.

• 

  The Launcher Log tab after the Launcher starts

• 

  The Local Version Editor (NYI) tab (replaced by Time Machine)

• 

  Error message that is displayed if a development launcher is outdated

• 

  Error message that is displayed if you open an old launcher after using the 2.0 launcher

• 

  Profile icons selection from launcher.

• 

  Launcher in offline mode

• 

  The Help page

• 

  Game crash

• 

  Launcher warns you to run another minecraft if you ran it already

Trivia

• In the top left corner a barely visible button can be found which randomly shows either a Creeper face or a shrug kaomoji ¯\_(ツ)_/¯. It glows white when clicked, but has no use at all
  • The Creeper face as well as the meme were used for the language selection menu during the beta phase of the launcher, but when a globe was added instead both were simply moved downwards to be kept as an Easter egg
• If you hover long enough over the "Play" button, random mobs will appear on the right side of the window.

See also

• Programs and Editors