# Duplicate callback outputs when restarting the dash app

**URL:** <https://community.plotly.com/t/duplicate-callback-outputs-when-restarting-the-dash-app/74299>\
**Category:** Dash Python\
**Tags:** question\
**Created:** [April 10, 2023, 8:25pm UTC](https://community.plotly.com/t/duplicate-callback-outputs-when-restarting-the-dash-app/74299 "2023-04-10T20:25:43Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![hoatran](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/hoatran/32/21447_2.png) [@hoatran](https://community.plotly.com/u/hoatran)\
**Post date:** [April 11, 2023, 1:53am UTC](https://community.plotly.com/t/duplicate-callback-outputs-when-restarting-the-dash-app/74299/2 "2023-04-11T01:53:45Z")

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> [@tararu](#):
>
> ```auto
> @app.callback(
> Output("plot", "figure"), 
> [Input("plot-picker", "value"), Input("test-picker", "value")])
> 
> ```

I see in your code this callback showed 2 times so I think it could be a reason. Try to delete one and I think it could work. If you want to use `duplicate_callback` you could refer this link about 2.9 version of Dash.

> [@mega Dash 2.9.2 Released - Partial Property Updates with Patch(), Duplicate Outputs, dcc.Geolocation, Scatter Group Attributes and More](https://community.plotly.com/t/dash-2-9-2-released-partial-property-updates-with-patch-duplicate-outputs-dcc-geolocation-scatter-group-attributes-and-more/72114):
>
> Update : [version 2.11.0 has been released](https://community.plotly.com/t/dash-2-11-0-released-dash-in-jupyter-locked-flask-versions-and-dcc-graph-updates/76494) since this was posted. We’re excited to announce that Dash 2.9.2 has been released rocket Register for the [upcoming webinar](https://go.plotly.com/dash-partial-properties?utm_source=Webinar%3A+Partial+Properties+5%2F17%2F25&utm_medium=community_forum&utm_content=announcement_post) to learn how to use the open-source feature. pip install dash==2.9.2 Official Changelog arrow_forward [Dash v2.9.2](https://github.com/plotly/dash/blob/dev/CHANGELOG.md)Highlights arrow_down_smallPartial Property Updates with Patch() Partial Property Updates can improve the performance of your Dash apps by preventing unnecessary computation, data fetching, and reducing …

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