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import panel as pn


The FloatSlider widget allows selecting selecting a numeric floating-point value within a set bounds using a slider.

Discover more on using widgets to add interactivity to your applications in the how-to guides on interactivity. Alternatively, learn how to set up callbacks and (JS-)links between parameters or how to use them as part of declarative UIs with Param.


For details on other options for customizing the component see the layout and styling how-to guides.


  • start (float): The range’s lower bound

  • end (float): The range’s upper bound

  • step (float): The interval between values

  • value (float): The selected value as a float type

  • value_throttled (float): The selected value as a float type throttled until mouseup


  • bar_color (color): Color of the slider bar as a hexadecimal RGB value

  • direction (str): Whether the slider should go from left to right (‘ltr’) or right to left (‘rtl’)

  • disabled (boolean): Whether the widget is editable

  • format (str, bokeh.models.TickFormatter): Formatter to apply to the slider value

  • name (str): The title of the widget

  • orientation (str): Whether the slider should be displayed in a ‘horizontal’ or ‘vertical’ orientation.

  • tooltips (boolean): Whether to display tooltips on the slider handle

float_slider = pn.widgets.FloatSlider(name='Float Slider', start=0, end=3.141, step=0.01, value=1.57)


The FloatSlider value is returned as a float and can be accessed and set like any other widget:


A custom format string or bokeh TickFormatter may be used to format the slider values:

from bokeh.models.formatters import PrintfTickFormatter

str_format = pn.widgets.FloatSlider(name='Distance', format='1[.]00')

tick_format = pn.widgets.FloatSlider(name='Distance', format=PrintfTickFormatter(format='%.3f m'))

pn.Column(str_format, tick_format)


The FloatSlider widget exposes a number of options which can be changed from both Python and Javascript. Try out the effect of these parameters interactively:

pn.Row(float_slider.controls(jslink=True), float_slider)

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