Keyboard navigation and screen-reader semantics in notebook cell workflows vary between classic Notebook and Notebook 7

Direct answer

For deployments requiring keyboard-only navigation and screen-reader compatibility, Notebook 7 should be treated as the supported accessible target. Classic Notebook is in maintenance and lacks newer ARIA enhancements. However, cell focus, run state, and output region announcements are not guaranteed to behave consistently between classic Notebook and Notebook 7 on the same content. Documented accessibility limitations for Notebook 7 depend on the exact JupyterLab version it bundles and on the widget libraries used in the notebook.

Confirmed architecture vs. likely version drift

Confirmed: Classic Notebook uses its own HTML template with limited ARIA landmarks; cell selection is announced mainly through title attribute changes. Notebook 7 reuses the JupyterLab front-end, exposing a richer DOM with ARIA roles, live regions, and a focus tracker. Likely explanation for inconsistent announcements: Notebook 7 tracks JupyterLab releases, so accessibility fixes may appear upstream in JupyterLab before they are packaged or documented for Notebook users. Additionally, the accessibility of dynamically rendered outputs and third-party widgets depends on the individual extension or widget library implementation and is not uniformly guaranteed by the core interface.

Steps to verify your deployment

Because the question does not specify the deployed version, the following steps are required before treating Notebook 7 as fully accessible in your environment.

1. Identify the exact Notebook 7 version and the JupyterLab version it bundles. This determines which accessibility fixes are included.
2. Deploy a test notebook with a code cell, a markdown cell, and a representative dynamically rendered output (for example, an ipywidget or interactive plot).
3. Navigate using only the keyboard—Tab, Shift+Tab, Enter, Esc, and arrow keys—while running a screen reader such as NVDA, JAWS, or VoiceOver.
4. Record the spoken announcements for cell focus changes, execution state transitions (idle/busy), and output region updates.
5. Repeat the same test in classic Notebook with the same kernel to document behavioral differences.
6. Consult the release notes for the bundled JupyterLab version to confirm whether accessibility fixes relevant to your workflow are present. If critical fixes are missing, upgrade to a newer Notebook 7 patch release.
7. Verify that administrator keyboard shortcut overrides have not disabled default navigation keys (run cell, move focus).

Documented limitations to check

Documented accessibility limitations are inherited from the underlying JupyterLab release and from widget libraries. Large HTML or SVG outputs that are not wrapped in ARIA live regions may cause delayed or missing screen-reader announcements. Custom JupyterLab keyboard shortcuts or administrator-overridden shortcuts can disable essential navigation keys. The accessibility of specific widgets—such as ipywidgets, plotly, or bqplot—depends on the widget library version and may remain incomplete even in the latest Notebook 7.

One missing diagnostic detail

Please provide the exact Notebook 7 version and the JupyterLab version it bundles. This single detail changes the recommendation: it determines whether known accessibility fixes are already present or whether an upgrade is the necessary first step.