JupyterLab Changelog


October 3, 2018

See the JupyterLab 0.35.0 milestone on GitHub for the full list of pull requests and issues closed.


  • A notebook cell can now be readonly, reflecting its enabled metadata. (#5401, #1312)

  • Add “Go To Line” in the Edit menu for text editors. (#5377)

  • Sidebar panels can now be switched between left and right sidebars. Right-click on a sidebar tab to move it to the other sidebar. (#5347, #5054, #3707)

  • Make the sidebar a bit narrower, and make the minimum width adjustable from a theme. (#5245)

  • Populate the File, Export Notebook As… submenu from the server nbconvert capabilities. (#5217)

  • Server contents managers can now tell JupyterLab to open files as notebooks. For example, several custom contents managers save and open notebooks as Markdown files. (#5247, #4924)

  • Add a command-line interface for managing workspaces. (#5166)

  • Allow safe inline CSS styles in Markdown. (#5012, #1812)

  • Add Quit to File menu when appropriate. (#5226, #5252, #5246, #5280)

  • Rework extension manager user experience. (#5147, #5042)

Dark theme

  • Show a dark splash screen when using a dark theme. (#5339, #5338, #5403)

  • Fix code completion menu for a dark theme. (#5364, #5349)

  • Style CSV viewer for a dark theme. (#5304, #3456)

  • Make Matplotlib figures legible in a dark theme. (#5232)

  • Fix notebook cell dropdown legibility in a dark theme. (#5168)

Bug fixes

  • Various save options in the file menu and toolbar are now disabled when a file is not writable. (#5376, #5391)

  • Kernel selector dialog no longer cuts off kernel names. (#5260, #5181)

  • Fix focus issues with the toolbar. (#5344, #5324, #2995, #5328)

  • Fix toolbar button enabled/disabled status. (#5278)

  • Table alignment is now respected in Markdown. (#5301, #3180)

  • Fix syntax highlighting for Markdown lists. (#5297, #2741)

  • Use the current filebrowser instead of the default one for various commands. (#5390)

  • Fix escaping in link handling to conform to Markdown syntax. This means that spaces in link references now need to be encoded as %20. (#5383, #5340, #5153)

Build system

  • Use Typescript 3.1. (#5360)

  • Use Lerna 3.2.1. (#5262)

  • Node >=6.11.5 is now required. (#5227)

  • Pin vega-embed version to 3.18.2. (#5342)

  • Use Jest for services tests. (#5251, #5282)

  • Make it easier for third party extensions to use the JupyterLab test app and testing utilities. (#5415)

  • Fix jupyter lab clean on Windows. (#5400, #5397)

  • Fix jupyter lab build on NFS. (#5237, #5233)

  • Build wheels for Python 3 only. (#5287)

  • Migrate to using jupyterlab_server instead of jupyterlab_launcher and fix the app example. (#5316)

  • Move Mathjax 2 typesetter to a library package. (#5259, #5257)

For Developers

  • Default toolbar buttons can be overridden, and mime renderers can now specify toolbar buttons. (#5398, #5370, #5363)

  • A JupyterLab application instance can now be given a document registry, service manager, and command linker. (#5291)


August 18, 2018

See the JupyterLab 0.34.0 milestone on GitHub for the full list of pull requests and issues closed.

Key Features

  • Notebooks, consoles, and text files now have access to completions for local tokens.

  • Python 3.5+ is now required to use JupyterLab. Python 2 kernels can still be run within JupyterLab.

  • Added the pipe (|) character as a CSV delimiter option.

  • Added “Open From Path…”” to top level File menu.

  • Added “Copy Download Link” to context menu for files.

Changes for Developers

  • Notebooks, consoles, and text files now have access to completions for local tokens. If a text file has a running kernel associated with its path (as happens with an attached console), it also gets completions and tooltips from that kernel. (#5049)

  • The FileBrowser widget has a new constructor option refreshInterval, allowing the creator to customize how often the widget polls the storage backend. This can be useful to prevent rate-limiting in certain contexts. (#5048)

  • The application shell now gets a pair of CSS data attributes indicating the current theme, and whether it is light or dark. Extension authors can write CSS rules targeting these to have their extension UI elements respond to the application theme. For instance, to write a rule targeting whether the theme is overall light or dark, you can use

    [data-theme-light="true"] your-ui-class {
      background-color: white;
    [data-theme-light="false"] your-ui-class {
      background-color: black;

    The theme name can also be targeted by writing CSS rules for data-theme-name. (#5078)

  • The IThemeManager interface now exposes a signal for themeChanged, allowing extension authors to react to changes in the theme. Theme extensions must also provide a new boolean property isLight, declaring whether they are broadly light colored. This data allows third-party extensions to react better to the active application theme. (#5078)

  • Added a patch to update the uploads for each FileBrowserModel instantly whenever a file upload errors. Previously, the upload that erred was only being removed from uploads upon an update. This would allow the status bar component and other extensions that use the FileBrowserModel to be more precise. (#5077)

  • Cell IDs are now passed in the shell message as part of the cell metadata when a cell is executed. This helps in developing reactive kernels. (#5033)

  • The IDs of all deleted cells since the last run cell are now passed as part of the cell metadata on execution. The IDs of deleted cells since the last run cell are stored as deletedCells in NotebookModel. This helps in developing reactive kernels. (#5037)

  • The ToolbarButton in apputils has been refactored with an API change and now uses a React component ToolbarButtonComponent to render its children. It is now a div with a single button child, which in turn as two span elements for an icon and text label. Extensions that were using the className options should rename it as iconClassName. The className options still exists, but it used as the CSS class on the button element itself. The API changes were done to accommodate styling changes to the button. (#5117)

  • The Toolbar.createFromCommand function has been replaced by a dedicated ToolbarButton subclass called CommandToolbarButton, that wraps a similarly named React component. (#5117)

  • The design and styling of the right and left sidebars tabs has been improved to address #5054. We are now using icons to render tabs for the extensions we ship with JupyterLab and extension authors are encouraged to do the same (text labels still work). Icon based tabs can be used by removing widget.caption and adding widget.iconClass = '<youriconclass> jp-SideBar-tabIcon';. (#5117)

  • The style of buttons in JupyterLab has been updated to a borderless design. (#5117)

  • A new series of helper CSS classes for stying SVG-based icons at different sizes has been added: jp-Icon, jp-Icon-16, jp-Icon-18, jp-Icon-20.

  • The rank of the default sidebar widget has been updated. The main change is giving the extension manager a rank of 1000 so that it appears at the end of the default items.

  • Python 3.5+ is now required to use JupyterLab. Python 2 kernels can still be run within JupyterLab. (#5119)

  • JupyterLab now uses yarn 1.9.4 (aliased as jlpm), which now allows uses to use Node 10+. (#5121)

  • Clean up handling of baseUrl and wsURL for PageConfig and ServerConnection. (#5111)

Other Changes

  • Added the pipe (|) character as a CSV delimiter option. (#5112)

  • Added Open From Path... to top level File menu. (#5108)

  • Added a saveState signal to the document context object. (#5096)

  • Added “Copy Download Link” to context menu for files. (#5089)

  • Extensions marked as deprecated are no longer shown in the extension manager. (#5058)

  • Remove In and Out text from cell prompts. Shrunk the prompt width from 90px to 64px. In the light theme, set the prompt colors of executed console cells to active prompt colors and reduced their opacity to 0.5. In the dark theme, set the prompt colors of executed console cells to active prompt colors and set their opacity to 1. (#5097 and #5130)

Bug Fixes

  • Fixed a bug in the rendering of the “New Notebook” item of the command palette. (#5079)

  • We only create the extension manager widget if it is enabled. This prevents unnecessary network requests to npmjs.com. (#5075)

  • The running panel now shows the running sessions at startup. (#5118)

  • Double clicking a file in the file browser always opens it rather than sometimes selecting it for a rename. (#5101)


July 26, 2018

See the JupyterLab 0.33.0 milestone on GitHub for the full list of pull requests and issues closed.

No longer in beta

In JupyterLab 0.33, we removed the “Beta” label to better signal that JupyterLab is ready for users to use on a daily basis. The extension developer API is still being stabilized. See the release blog post for details. (#4898, #4920)


We added new workspace support, which enables you to have multiple saved layouts, including in different browser windows. See the workspace documentation for more details. (#4502, #4708, #4088, #4041 #3673, #4780)

Keyboard shortcuts

  • “Save As…” given the keyboard shortcut Ctrl/Cmd Shift S. (#4560)

  • “Run All Cells” given the keyboard shortcut Ctrl/Cmd Shift Enter. (#4558)

  • “notebook:change-to-cell-heading-X” keyboard shortcuts (and commands) renamed to “notebook:change-cell-to-heading-X” for X=1…6. This fixes the notebook command-mode keyboard shortcuts for changing headings. (#4430)

  • The console execute shortcut can now be set to either Enter or Shift Enter as a Console setting. (#4054)

Command palette items

  • “Notebook” added to the command palette to open a new notebook. (#4812)

  • “Run Selected Text or Current Line in Console” added to the command palette to run the selected text or current line from a notebook in a console. A default keyboard shortcut for this command is not yet provided, but can be added by users with the notebook:run-in-console command. To add a keyboard shortcut Ctrl G for this command, use the “Settings” | “Advanced Settings Editor” menu item to open the “Keyboard Shortcuts” advanced settings, and add the following JSON in the shortcut JSON object in the User Overrides pane (adjust the actual keyboard shortcut if you wish). (#3453, #4206, #4330)

    "notebook:run-in-console": {
      "command": "notebook:run-in-console",
      "keys": ["Ctrl G"],
      "selector": ".jp-Notebook.jp-mod-editMode"
  • The command palette now renders labels, toggled state, and keyboard shortcuts in a more consistent and correct way. (#4533, #4510)


  • “fontFamily”, “fontSize”, and “lineHeight” settings added to the text editor advanced settings. (#4673)

  • Solarized dark and light text editor themes from CodeMirror. (#4445)

Larger file uploads

  • Support for larger file uploads (>15MB) when using Jupyter notebook server version >= 5.1. (#4224)

Extension management and installation

  • New extension manager for installing JupyterLab extensions from npm within the JupyterLab UI. You can enable this from the Advanced Settings interface. (#4682, #4925)

  • Please note that to install extensions in JupyterLab, you must use NodeJS version 9 or earlier (i.e., not NodeJS version 10). We will upgrade yarn, with NodeJS version 10 support, when a bug in yarn is fixed. (#4804)

Interface changes

  • Wider tabs in the main working area to show longer filenames. (#4801)

  • Initial kernel selection for a notebook or console can no longer be canceled: the user must select a kernel. (#4596)

  • Consoles now do not display output from other clients by default. A new “Show All Kernel Activity” console context menu item has been added to show all activity from a kernel in the console. (#4503)

  • The favicon now shows the busy status of the kernels in JupyterLab. (#4361, #3957, #4966)


  • JupyterLab now ships with a Vega4 renderer by default (upgraded from Vega3). (#4806)

  • The HTML sanitizer now allows some extra tags in rendered HTML, including kbd, sup, and sub. (#4618)

  • JupyterLab now recognizes the .tsv file extension as tab-separated files. (#4684)

  • Javascript execution in notebook cells has been re-enabled. (#4515)

Changes for developers

  • A new signal for observing application dirty status state changes. (#4840)

  • A new signal for observing notebook cell execution. (#4740, #4744)

  • A new anyMessage signal for observing any message a kernel sends or receives. (#4437)

  • A generic way for different widgets to register a “Save with extras” command that appears in the File menu under save. (#3981)

  • A new API for removing groups from a JupyterLab menu. addGroup now returns an IDisposable which can be used to remove the group. removeGroup has been removed. (#4890)

  • The Launcher now uses commands from the application CommandRegistry to launch new activities. Extension authors that add items to the launcher will need to update them to use commands. (#4757)

  • There is now a top-level addToBottomArea function in the application, allowing extension authors to add bottom panel items like status bars. (#4752)

  • Rendermime extensions can now indicate that they are the default rendered widget factory for a file-type. For instance, the default widget for a markdown file is a text editor, but the default rendered widget is the markdown viewer. (#4692)

  • Add new workspace REST endpoints to jupyterlab_server and make them available in @jupyterlab/services. (#4841)

  • Documents created with a mimerenderer extension can now be accessed using an IInstanceTracker which tracks them. Include the token IMimeDocumentTracker in your plugin to access this. The IInstanceTracker interface has also gained convenience functions find and filter to simplify iterating over instances. (#4762)

  • RenderMime render errors are now displayed to the user. (#4465)

  • getNotebookVersion is added to the PageConfig object. (#4224)

  • The session kernelChanged signal now contains both the old kernel and the new kernel to make it easy to unregister things from the old kernel. (#4834)

  • The connectTo functions for connecting to kernels and sessions are now synchronous (returning a connection immediately rather than a promise). The DefaultSession clone and update methods are also synchronous now. (#4725)

  • Kernel message processing is now asynchronous, which guarantees the order of processing even if a handler is asynchronous. If a kernel message handler returns a promise, kernel message processing is paused until the promise resolves. The kernel’s anyMessage signal is emitted synchronously when a message is received before asynchronous message handling, and the iopubMessage and unhandledMessage signals are emitted during asynchronous message handling. These changes mean that the comm onMsg and onClose handlers and the kernel future onReply, onIOPub, and onStdin handlers, as well as the comm target and message hook handlers, may be asynchronous and return promises. (#4697)

  • Kernel comm targets and message hooks now are unregistered with removeCommTarget and removeMessageHook, instead of using disposables. The corresponding registerCommTarget and registerMessageHook functions now return nothing. (#4697)

  • The kernel connectToComm function is synchronous, and now returns the comm rather than a promise to the comm. (#4697)

  • The KernelFutureHandler class expectShell constructor argument is renamed to expectReply. (#4697)

  • The kernel future done returned promise now resolves to undefined if there is no reply message. (#4697)

  • The IDisplayDataMsg is updated to have the optional transient key, and a new IUpdateDisplayDataMsg type was added for update display messages. (#4697)

  • The uuid function from @jupyterlab/coreutils is removed. Instead import UUID from @phosphor/coreutils and use UUID.uuid4() . (#4604)

  • Main area widgets like the launcher and console inherit from a common MainAreaWidget class which provides a content area (.content) and a toolbar (.toolbar), consistent focus handling and activation behavior, and a spinner displayed until the given reveal promise is resolved. Document widgets, like the notebook and text editor and other documents opened from the document manager, implement the IDocumentWidget interface (instead of DocumentRegistry.IReadyWidget), which builds on MainAreaWidget and adds a .context attribute for the document context and makes dirty handling consistent. Extension authors may consider inheriting from the MainAreaWidget or DocumentWidget class for consistency. Several effects from these changes are noted below. (#3499, #4453)

    • The notebook panel .notebook attribute is renamed to .content.

    • The text editor is now the .content of a DocumentWidget, so the top-level editor widget has a toolbar and the editor itself is widget.content.editor rather than just widget.editor.

    • Mime documents use a MimeContent widget embedded inside of a DocumentWidget now.

    • Main area widgets and document widgets now have a revealed promise which resolves when the widget has been revealed (i.e., the spinner has been removed). This should be used instead of the ready promise.

Changes in the JupyterLab code infrastructure include:

  • The JupyterLab TypeScript codebase is now compiled to ES2015 (ES6) using TypeScript 2.9. We also turned on the TypeScript esModuleInterop flag to enable more natural imports from non-es2015 JavaScript modules. With the update to ES2015 output, code generated from async/await syntax became much more manageable, so we have started to use async/await liberally throughout the codebase, especially in tests. Because we use Typedoc for API documentation, we still use syntax compatible with TypeScript 2.7 where Typedoc is used. Extension authors may have some minor compatibility updates to make. If you are writing an extension in TypeScript, we recommend updating to TypeScript 2.9 and targeting ES2015 output as well. (#4462, #4675, #4714, #4797)

  • The JupyterLab codebase is now formatted using Prettier. By default the development environment installs a pre-commit hook that formats your staged changes. (#4090)

  • Updated build infrastructure using webpack 4 and better typing. (#4702, #4698)

  • Upgraded yarn to version 1.6. Please note that you must use NodeJS version 9 or earlier with JupyterLab (i.e., not NodeJS version 10). We will upgrade yarn, with NodeJS version 10 support, when a bug in yarn is fixed. (#4804)

  • Various process utilities were moved to jupyterlab_server. (#4696)

Other fixes

  • Fixed a rendering bug with the Launcher in single-document mode. (#4805)

  • Fixed a bug where the native context menu could not be triggered in a notebook cell in Chrome. (#4720)

  • Fixed a bug where the cursor would not show up in the dark theme. (#4699)

  • Fixed a bug preventing relative links from working correctly in alternate IDrives. (#4613)

  • Fixed a bug breaking the image viewer upon saving the image. (#4602)

  • Fixed the font size for code blocks in notebook Markdown headers. (#4617)

  • Prevented a memory leak when repeatedly rendering a Vega chart. (#4904)

  • Support dropped terminal connection re-connecting. (#4763, #4802)

  • Use require.ensure in vega4-extension to lazily load vega-embed and its dependencies on first render. (#4706)

  • Relative links to documents that include anchor tags will now correctly scroll the document to the right place. (#4692)

  • Fix default settings JSON in setting editor. (#4591, #4595)

  • Fix setting editor pane layout’s stretch factor. (#2971, #4772)

  • Programmatically set settings are now output with nicer formatting. (#4870)

  • Fixed a bug in displaying one-line CSV files. (#4795, #4796)

  • Fixed a bug where JSON arrays in rich outputs were collapsed into strings. (#4480)

Beta 2 (v0.32.0)

Apr 16, 2018

This is the second in the JupyterLab Beta series of releases. It contains many enhancements, bugfixes, and refinements, including:

  • Better handling of a corrupted or invalid state database. (#3619, #3622, #3687, #4114).

  • Fixing file dirty status indicator. (#3652).

  • New option for whether to autosave documents. (#3734).

  • More commands in the notebook context menu. (#3770, #3909)

  • Defensively checking for completion metadata from kernels. (#3888)

  • New “Shutdown all” button in the Running panel. (#3764)

  • Performance improvements wherein non-focused documents poll the server less. (#3931)

  • Changing the keyboard shortcut for singled-document-mode to something less easy to trigger. (#3889)

  • Performance improvements for rendering text streams, especially around progress bars. (#4045).

  • Canceling a “Restart Kernel” now functions correctly. (#3703).

  • Defer loading file contents until after the application has been restored. (#4087).

  • Ability to rotate, flip, and invert images in the image viewer. (#4000)

  • Major performance improvements for large CSV viewing. (#3997).

  • Always show the context menu in the file browser, even for an empty directory. (#4264).

  • Handle asynchronous comm messages in the services library more correctly (Note: this means @jupyterlab/services is now at version 2.0!) ([#4115](https://github.com/jupyterlab/jupyterlab/issues/4115)).

  • Display the kernel banner in the console when a kernel is restarted to mark the restart ([#3663](https://github.com/jupyterlab/jupyterlab/issues/3663)).

  • Many tweaks to the UI, as well as better error handling.


Dec 05, 2017


Nov 17, 2017

Bug fix for file browser right click handling. https://github.com/jupyterlab/jupyterlab/issues/3019


Nov 09, 2017

  • Create new view of cell in cell context menu. #3159

  • New Renderers for VDOM and JSON mime types and files. #3157

  • Switch to React for our VDOM implementation. Affects the VDomRenderer class. #3133

  • Standalone Cell Example. #3155


Oct 16, 2017

This release generally focuses on developer and extension author enhancements and general bug fixes.

  • Plugin id and schema file conventions change. https://github.com/jupyterlab/jupyterlab/pull/2936.

  • Theme authoring conventions change. #3061

  • Enhancements to enabling and disabling of extensions. #3078

  • Mime extensions API change (name -> id and new naming convention). #3078

  • Added a jupyter lab --watch mode for extension authors. #3077

  • New comprehensive extension authoring tutorial. #2921

  • Added the ability to use an alternate LaTeX renderer. #2974

  • Numerous bug fixes and style enhancements.


Aug 23, 2017


Jul 21, 2017


Jul 07, 2017


Jun 16, 2017

  • Overhaul of the launcher. #2380

  • Initial implementation of client-side settings system. #2157

  • Updatable outputs. #2439

  • Use new Phosphor Datagrid for CSV viewer. #2433

  • Added ability to enable/disable extensions without rebuilding. #2409

  • Added language and tab settings for the file viewer. #2406

  • Improvements to real time collaboration experience. #2387 #2333

  • Compatibility checking for extensions. #2410

  • Numerous bug fixes and style improvements.


Jun 02, 2017


May 18, 2017


Apr 21, 2017

Release Notes:

Numerous bug fixes and improvements.


Apr 04, 2017

Mainly backend-focused release with compatibility with Phosphor 1.0 and a big refactor of session handling (the ClientSession class) that provides a simpler object for classes like notebooks, consoles, inspectors, etc. to use to communicate with the API. Also includes improvements to the development workflow of JupyterLab itself after the big split.

https://github.com/jupyterlab/jupyterlab/pull/1984 https://github.com/jupyterlab/jupyterlab/pull/1927


Mar 21, 2017


Mar 01, 2017


Feb 09, 2017

  • Adds a Cell Tools sidebar that allows you to edit notebook cell metadata. #1586.

  • Adds keyboard shortcuts to switch between tabs (Cmd/Ctrl LeftArrow and Cmd/Ctrl RightArrow). #1647

  • Upgrades to xterm.js 2.3. #1664

  • Fixes a bug in application config, but lab extensions will need to be re-enabled. #1607

  • Numerous other bug fixes and style improvements.