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Rename z label in contour plot plotly js

var data = [ {
  z: [[10, 10.625, 12.5, 15.625, 20],
       [5.625, 6.25, 8.125, 11.25, 15.625],
       [2.5, 3.125, 5., 8.125, 12.5],
       [0.625, 1.25, 3.125, 6.25, 10.625],
       [0, 0.625, 2.5, 5.625, 10]],
  type: 'contour',
  colorscale: [[0, 'rgb(166,206,227)'], [0.25, 'rgb(31,120,180)'], [0.45, 'rgb(178,223,138)'], [0.65, 'rgb(51,160,44)'], [0.85, 'rgb(251,154,153)'], [1, 'rgb(227,26,28)']]
}
];

var layout = {
  title: 'Custom Contour Plot Colorscale'
};

Plotly.newPlot('myDiv', data, layout);

i want to change the z-index label in plotlyjs i am using the following code. it currently shows X,Y,Z on hover. X, Y values are good want to know if there is some way where we can change the value label of Y? on hover on the graph i want z to be shown as ‘Value’. How to get that?

Thanks for using plotly.js!
You could use hoveretemplate.
Here is a demo based on your code.
For more info please visit: https://plot.ly/javascript/reference/#contour-hovertemplate