# Update observables only when slider is released

**URL:** <https://discourse.julialang.org/t/update-observables-only-when-slider-is-released/136742>\
**Category:** Visualization\
**Tags:** makie\
**Created:** [April 16, 2026, 6:30pm UTC](https://discourse.julialang.org/t/update-observables-only-when-slider-is-released/136742 "2026-04-16T18:30:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![juliohm](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/juliohm/32/215266_2.png) [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Post date:** [April 16, 2026, 6:30pm UTC](https://discourse.julialang.org/t/update-observables-only-when-slider-is-released/136742/1 "2026-04-16T18:30:03Z")

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For expensive computations, how can we slide on a `Slider` without triggering all intermediate values? One workaround is to add a separate `Toggle` to turn the computation on/off, but that adds unnecessary logic to the application. Is there a `LazySlider` or similar widget in Makie.jl?

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**Author:** ![Uve](https://avatars.discourse-cdn.com/v4/letter/u/82dd89/32.png) [@Uve](https://discourse.julialang.org/u/Uve)\
**Post date:** [April 16, 2026, 7:02pm UTC](https://discourse.julialang.org/t/update-observables-only-when-slider-is-released/136742/2 "2026-04-16T19:02:30Z")

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`Slider` has the keyword `update_while_dragging`. Set it to `false` to only emit a value when the user releases the handle, avoiding intermediate updates.

> **[update\_while\_dragging ​ - Slider | Makie](https://docs.makie.org/dev/reference/blocks/slider#update_while_dragging)**
>
> A simple slider without a label. You can create a label using a Label object, for example. You need to specify a range that constrains the slider's possible values. | Create impressive data visualizations with Makie, the plotting ecosystem for the...

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<div class="post-metadata">

**Author:** ![juliohm](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/juliohm/32/215266_2.png) [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Post date:** [April 17, 2026, 11:55am UTC](https://discourse.julialang.org/t/update-observables-only-when-slider-is-released/136742/3 "2026-04-17T11:55:39Z")

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For future reference, this same option is available in the `SliderGrid` if you loop over the constituent sliders and set it afterwards:

```julia
grid = SliderGrid(...)

for slider in grid.sliders
  slider.update_while_dragging[] = false
end
```