If Chart.js is not showing tooltips on hover with small data, there could be a few reasons for this behavior. Here are some possible causes and solutions:

  1. Tooltip Configuration: By default, Chart.js tooltips are enabled, but it's possible that tooltips were explicitly disabled or customized in your chart configuration. Ensure that tooltips are enabled by setting tooltips: { enabled: true } in your chart options:

    var options = { tooltips: { enabled: true, }, // Other chart options... };
  2. Responsive Sizing: Chart.js tooltips may not appear correctly if the chart canvas is too small. Make sure the chart container has enough space to display tooltips properly. If the chart is responsive, check if the tooltips appear when the chart size is increased.

  3. Custom Chart Styling: If you have custom CSS styles applied to your chart, it's possible that they interfere with tooltip display. Check for any conflicting styles that may hide or obscure the tooltips.

  4. Low Data Point Threshold: Chart.js has a hover.mode option that determines when tooltips should be shown. For very few data points, the default nearest mode might not trigger tooltips. You can try setting the hover.mode to single or index to force tooltips to show:

    var options = { hover: { mode: 'single', // or 'index' }, // Other chart options... };
  5. Chart Type: The type of chart you are using might also affect tooltip behavior. For certain chart types, such as Pie or Doughnut charts, tooltips might not be as relevant or useful. Make sure you are using a chart type that supports tooltips.

  6. Chart Data: If your data contains missing or undefined values, it could interfere with the tooltip display. Check that your data points are valid and well-formed.

  7. Chart.js Version: Ensure that you are using the latest stable version of Chart.js. Older versions may have bugs or issues that are fixed in newer releases.

  8. Other Libraries or Code Interference: Check for any other libraries or custom code that might interfere with Chart.js tooltip behavior. It's possible that other scripts are conflicting or overriding Chart.js functionality.

By inspecting your chart configuration, reviewing the chart size, and ensuring that tooltips are enabled, you should be able to identify and resolve the issue with tooltips not showing on hover with small data in Chart.js. If the problem persists, consider creating a minimal example of the issue and reviewing Chart.js documentation and GitHub issues for additional insights.

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