JupyterLab-A11y-Checker¶
JupyterLab-A11y-Checker is a JupyterLab extension that helps authors detect and fix common accessibility issues in Jupyter Notebooks, aligning with WCAG 2.1 AA guidelines. It combines the strengths of axe-core, a widely used accessibility engine, with custom notebook-specific detection algorithms that address issues axe cannot reliably cover in JupyterLab. Specifically the extension can:
Detect accessibility issues in images, headings, tables, and links(see Rules).
Apply targeted fixes to those issues via guided interfaces (see Fix Interfaces).
Optionally use AI assistance (LLM / VLM) to draft suggestions for certain usecases.
Repository: Jupyterlab-a11y-checker on GitHub
Figure 1:The extension detects accessibility issues in a notebook and provides notebook authors with assistance to fix those issues.
The extension focuses on the following issues:
Missing Alternative Text (Alt Text) for images in Markdown cells.
Notebook Lacks a Primary Heading (H1), which should serve as the notebook’s main title.
Multiple H1 Headings present in the notebook (should only be one for the title).
Duplicate Heading Text across different sections of the notebook.
Empty Heading elements (e.g.,
##) identified.Missing Table Headers (row or column headers) in Markdown tables.
Missing Table Caption to summarize the table’s content.
Missing Table Scope attributes for table headers, required for complex data tables.
Insufficient Color Contrast for text within images or image outputs.
Indiscernible Link Text (e.g., “click here,” or bare URLs) in Markdown cells.
You can read more about these issues in the rules page