# \#hover

**URL:** https://discourse.bokeh.org/tag/hover/4.md

[Latest](https://discourse.bokeh.org/latest.md) · [Categories](https://discourse.bokeh.org/categories.md) · [Tags](https://discourse.bokeh.org/tags.md)

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## [Hints about writing a timeline viewer](https://discourse.bokeh.org/t/hints-about-writing-a-timeline-viewer/12726)

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**Author:** [@Roger](https://discourse.bokeh.org/u/Roger)\
**Replies:** 3\
**Last updated:** [June 10, 2026, 5:14pm UTC](https://discourse.bokeh.org/t/hints-about-writing-a-timeline-viewer/12726 "2026-06-10T17:14:58Z")

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I have written a matplotlib application which scrolls through events on a timeline. It displays a frame of 25 years at a time along 500 years. However, I need to link the events to wikipedia, and matplotlib doesn’t do th…

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## [Enable/disable hover\_fill\_alpha on multi\_polygons](https://discourse.bokeh.org/t/enable-disable-hover-fill-alpha-on-multi-polygons/12623)

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**Author:** [@tmoulignier](https://discourse.bokeh.org/u/tmoulignier)\
**Replies:** 4\
**Last updated:** [October 22, 2025, 6:51am UTC](https://discourse.bokeh.org/t/enable-disable-hover-fill-alpha-on-multi-polygons/12623 "2025-10-22T06:51:21Z")

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Hello, i have a code where i plot a large amount of polygons using the multi\_polygons glyph. If i use the hover\_fill\_alpha parameter, things get laggy as the whole glyph gets redrawn everythime the mouse goes to another…

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## [Plot on Hover Tooltip](https://discourse.bokeh.org/t/plot-on-hover-tooltip/12471)

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**Author:** [@mixstam1453](https://discourse.bokeh.org/u/mixstam1453)\
**Replies:** 0\
**Last updated:** [June 12, 2025, 2:53pm UTC](https://discourse.bokeh.org/t/plot-on-hover-tooltip/12471 "2025-06-12T14:53:56Z")

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\# main.py import numpy as np import json from bokeh.io import curdoc from bokeh.models import ( GeoJSONDataSource, HoverTool, ColorBar, LinearColorMapper, BasicTicker, PrintfTickFormatter ) from bokeh.plotting…

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## [Smoothier Tooltip](https://discourse.bokeh.org/t/smoothier-tooltip/12452)

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**Author:** [@mixstam1453](https://discourse.bokeh.org/u/mixstam1453)\
**Replies:** 1\
**Last updated:** [June 6, 2025, 5:06pm UTC](https://discourse.bokeh.org/t/smoothier-tooltip/12452 "2025-06-06T17:06:57Z")

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Hello, For a long time, I have tried to make the hover tooltip smoothier. Here is a smoothier tooltip for scatter/line plots. It needs some further work/modification for other plots :blush:. from bokeh.plotting impor…

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## [Bokeh 3.6 is released!](https://discourse.bokeh.org/t/bokeh-3-6-is-released/12028)

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**Author:** [@Azaya89](https://discourse.bokeh.org/u/Azaya89)\
**Replies:** 0\
**Last updated:** [October 9, 2024, 5:17pm UTC](https://discourse.bokeh.org/t/bokeh-3-6-is-released/12028 "2024-10-09T17:17:46Z")

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Some features of this minor release include: Added support for n-gon glyph, including WebGL rendering Added support for axis click events Added support for “open in a new tab” mode to SaveTool Added support for click-s…

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## [Weather plots for snow and avalanche information](https://discourse.bokeh.org/t/weather-plots-for-snow-and-avalanche-information/9780)

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**Author:** [@tcarman](https://discourse.bokeh.org/u/tcarman)\
**Replies:** 1\
**Last updated:** [February 7, 2025, 5:25am UTC](https://discourse.bokeh.org/t/weather-plots-for-snow-and-avalanche-information/9780 "2025-02-07T05:25:41Z")

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We’ve built a web app using Bokeh as the foundation. The application has been live since 2017 using Bokeh as the plotting engine. The application and set of plots are specifically tailored to the snow and avalanche commu…

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## [Problem with CustomJSHover and \`@$name{custom}\` in \`vbar\_stack\` and \`area\_stack\` Glyphs](https://discourse.bokeh.org/t/problem-with-customjshover-and-name-custom-in-vbar-stack-and-area-stack-glyphs/12136)

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**Author:** [@ehsansaleh](https://discourse.bokeh.org/u/ehsansaleh)\
**Replies:** 0\
**Last updated:** [December 8, 2024, 3:48am UTC](https://discourse.bokeh.org/t/problem-with-customjshover-and-name-custom-in-vbar-stack-and-area-stack-glyphs/12136 "2024-12-08T03:48:47Z")

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Hi there, I’m trying to apply a customized JS hover formatter to the name field with the \*\_stack glyphs, and I can’t seem to figure it out. Notice that the same functionality works well for the x axis. Here’s a toy-exa…

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## [HoverTool styling background bokeh 3.5](https://discourse.bokeh.org/t/hovertool-styling-background-bokeh-3-5/12046)

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**Author:** [@matterda](https://discourse.bokeh.org/u/matterda)\
**Replies:** 3\
**Last updated:** [October 19, 2024, 1:17pm UTC](https://discourse.bokeh.org/t/hovertool-styling-background-bokeh-3-5/12046 "2024-10-19T13:17:16Z")

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I would like to have stylized tooltips (specifically, background color) upon hovering on a scatterplot’s points. The plot is rendered in the browser. It’s straightforward to get the tooltips with HoverTool, but I cannot …

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## [Custom hover tooltip over image plot not work as expected](https://discourse.bokeh.org/t/custom-hover-tooltip-over-image-plot-not-work-as-expected/11802)

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**Author:** [@annalong1991](https://discourse.bokeh.org/u/annalong1991)\
**Replies:** 3\
**Last updated:** [September 27, 2024, 7:54pm UTC](https://discourse.bokeh.org/t/custom-hover-tooltip-over-image-plot-not-work-as-expected/11802 "2024-09-27T19:54:40Z")

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Hello, I’m trying to use a custom tooltip on my heatmap. While with method 1 it works fine, with method 2 (custom tooltip) the tooltip shows me the entire data. However, I only want for the point I’m hovering (as it is …

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## [Adding Swatch + Multiple Columns in a Single Tooltip Field](https://discourse.bokeh.org/t/adding-swatch-multiple-columns-in-a-single-tooltip-field/11786)

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**Author:** [@Gen](https://discourse.bokeh.org/u/Gen)\
**Replies:** 5\
**Last updated:** [August 30, 2024, 1:27am UTC](https://discourse.bokeh.org/t/adding-swatch-multiple-columns-in-a-single-tooltip-field/11786 "2024-08-30T01:27:02Z")

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I have a simple CDS with two columns (title and fill\_color) I want to create a hover tooltip like the below (one single line with the title and swatch). tooltips=\[("Title", "@title $swatch:fill\_color")\] This produces …

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## [Modify CustomJS for HoverTool.callback and the CSS for the HoverTool](https://discourse.bokeh.org/t/modify-customjs-for-hovertool-callback-and-the-css-for-the-hovertool/11763)

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**Author:** [@Tenn0o8](https://discourse.bokeh.org/u/Tenn0o8)\
**Replies:** 3\
**Last updated:** [August 15, 2024, 3:57pm UTC](https://discourse.bokeh.org/t/modify-customjs-for-hovertool-callback-and-the-css-for-the-hovertool/11763 "2024-08-15T15:57:25Z")

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Hi all, I’m currently learning about the HoverTool and have some questions. Regarding the CustomJS callback: I’ve drawn some circles and applied the HoverTool, but I want the tooltips to appear only when I hover near t…

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## [How to Access Multiple dynamic number of data sources passed via args in CustomJS?](https://discourse.bokeh.org/t/how-to-access-multiple-dynamic-number-of-data-sources-passed-via-args-in-customjs/11754)

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**Author:** [@hannahhoang2704](https://discourse.bokeh.org/u/hannahhoang2704)\
**Replies:** 1\
**Last updated:** [August 13, 2024, 5:28pm UTC](https://discourse.bokeh.org/t/how-to-access-multiple-dynamic-number-of-data-sources-passed-via-args-in-customjs/11754 "2024-08-13T17:28:34Z")

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Hello, I’m learning Bokeh and have some issues trying to access args dict from CustomJS code. I’m working with a Bokeh plot that involves multiple ColumnDataSource objects. I need to dynamically access these data source…

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## [Bokeh HoverTool not showing timestamp in correct format](https://discourse.bokeh.org/t/bokeh-hovertool-not-showing-timestamp-in-correct-format/11487)

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**Author:** [@mayainevitable](https://discourse.bokeh.org/u/mayainevitable)\
**Replies:** 1\
**Last updated:** [April 25, 2024, 5:25pm UTC](https://discourse.bokeh.org/t/bokeh-hovertool-not-showing-timestamp-in-correct-format/11487 "2024-04-25T17:25:25Z")

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Whenever I plot any graph having the time in the “hh:mm:ss” format and use hover tool for seeing the timestamp in the same format at any point in the plot, I see a decimal number having an exponential degree. For exampl…

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## [How to get linked nodes in Bokeh GraphRenderer?](https://discourse.bokeh.org/t/how-to-get-linked-nodes-in-bokeh-graphrenderer/11452)

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**Author:** [@scoda](https://discourse.bokeh.org/u/scoda)\
**Replies:** 4\
**Last updated:** [April 15, 2024, 9:24pm UTC](https://discourse.bokeh.org/t/how-to-get-linked-nodes-in-bokeh-graphrenderer/11452 "2024-04-15T21:24:29Z")

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I like to change the style (fill\_color) of linked nodes (adjacent nodes) after a node selection. After selecting “C” I would like to change the style of “E” and “F”. How to get the linked nodes as object to change the s…

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## [How to arrange Bokeh networkx graph nodes in a grid?](https://discourse.bokeh.org/t/how-to-arrange-bokeh-networkx-graph-nodes-in-a-grid/11437)

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**Author:** [@scoda](https://discourse.bokeh.org/u/scoda)\
**Replies:** 2\
**Last updated:** [April 14, 2024, 6:59pm UTC](https://discourse.bokeh.org/t/how-to-arrange-bokeh-networkx-graph-nodes-in-a-grid/11437 "2024-04-14T18:59:02Z")

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I like to create rectangle elements in a grid, like in the periodic table. However some elements have to be connected to others, like edges between nodes in a graph. periodic table: periodic.py — Bokeh 2.4.1 Documentat…

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## [Non-English Column Names](https://discourse.bokeh.org/t/non-english-column-names/11257)

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**Author:** [@Gen](https://discourse.bokeh.org/u/Gen)\
**Replies:** 2\
**Last updated:** [February 14, 2024, 5:52am UTC](https://discourse.bokeh.org/t/non-english-column-names/11257 "2024-02-14T05:52:55Z")

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Can Bokeh’s Hovertool print data if the Column name is non-English in a ColumnDataSource? Here’s a quick example: import pandas as pd from bokeh.models.sources import ColumnDataSource from bokeh.plotting import figure,…

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## [HoverTool not disappearing in notebooks](https://discourse.bokeh.org/t/hovertool-not-disappearing-in-notebooks/11197)

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**Author:** [@someben](https://discourse.bokeh.org/u/someben)\
**Replies:** 0\
**Last updated:** [January 19, 2024, 6:42pm UTC](https://discourse.bokeh.org/t/hovertool-not-disappearing-in-notebooks/11197 "2024-01-19T18:42:23Z")

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I’m using Bokeh v3.3.1 in a Jupyter Lab v4.0.8 notebook environment, and doing a typical HoverTool thing: fig.add\_tools(bokeh.models.HoverTool( tooltips=\[(str(col), hover, )\], …

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## [Separate tooltips for separate traces in one graph](https://discourse.bokeh.org/t/separate-tooltips-for-separate-traces-in-one-graph/10955)

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**Author:** [@johann-petrak](https://discourse.bokeh.org/u/johann-petrak)\
**Replies:** 2\
**Last updated:** [October 30, 2023, 6:31pm UTC](https://discourse.bokeh.org/t/separate-tooltips-for-separate-traces-in-one-graph/10955 "2023-10-30T18:31:14Z")

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I want to create a graph that shows to data series (traces), one blue one red in combined line+scatter plot. I think I found out how to do this. However I would also like hover information to be shown for the data point…

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## [@Time Inaccurate display (cb\_data.indices repeat )](https://discourse.bokeh.org/t/time-inaccurate-display-cb-data-indices-repeat/10956)

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**Author:** [@srt111](https://discourse.bokeh.org/u/srt111)\
**Replies:** 3\
**Last updated:** [October 29, 2023, 7:50pm UTC](https://discourse.bokeh.org/t/time-inaccurate-display-cb-data-indices-repeat/10956 "2023-10-29T19:50:11Z")

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@Time used to display the current hovered time (nested dataframe), is showing inaccurate reading and doesn’t match with the corresponding Time Axis . Possibly due to the cb\_data.index.lineindices value being same for…

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## [How to add tooltips to tabpanels](https://discourse.bokeh.org/t/how-to-add-tooltips-to-tabpanels/10783)

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**Author:** [@heili77](https://discourse.bokeh.org/u/heili77)\
**Replies:** 1\
**Last updated:** [August 24, 2023, 4:34pm UTC](https://discourse.bokeh.org/t/how-to-add-tooltips-to-tabpanels/10783 "2023-08-24T16:34:58Z")

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I want to add a tooltip to tab panels describing the content shown in the panel. According to the documentation, tab panels do not support tooltips as description. So I tried to set the tab panel as target, but I get an…

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## [How to Style HoverTool CSS](https://discourse.bokeh.org/t/how-to-style-hovertool-css/10744)

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**Author:** [@behelit29](https://discourse.bokeh.org/u/behelit29)\
**Replies:** 0\
**Last updated:** [August 10, 2023, 12:54pm UTC](https://discourse.bokeh.org/t/how-to-style-hovertool-css/10744 "2023-08-10T12:54:13Z")

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In bokeh 3.0.0 and beyond, is there a way to pass the equivalent of stylesheets to HoverTool? I’m looking to change the text and background color of the hover itself. I’m working through upgrading from 2.4.2 to 3.2.1 and…

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## [Why was the "names" attribute removed from HoverTool](https://discourse.bokeh.org/t/why-was-the-names-attribute-removed-from-hovertool/10726)

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**Author:** [@behelit29](https://discourse.bokeh.org/u/behelit29)\
**Replies:** 3\
**Last updated:** [August 3, 2023, 5:52pm UTC](https://discourse.bokeh.org/t/why-was-the-names-attribute-removed-from-hovertool/10726 "2023-08-03T17:52:43Z")

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So I’ve decided to upgrade from Bokeh 2.4.2 to 3.2.1 so that I could use the “anchor” param when calling plot.image\_rgba(). That’s all working but now when I create hover tools I noticed it complains because the ‘names’ …

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## [Bokeh - Tooltips Not working with image\_rgba](https://discourse.bokeh.org/t/bokeh-tooltips-not-working-with-image-rgba/10576)

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**Author:** [@Gen](https://discourse.bokeh.org/u/Gen)\
**Replies:** 8\
**Last updated:** [June 23, 2023, 12:42am UTC](https://discourse.bokeh.org/t/bokeh-tooltips-not-working-with-image-rgba/10576 "2023-06-23T00:42:00Z")

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I’ve asked this question on Stackoverflow as well (python - Does bokehs \`image\_rgba()\` support hovertools? - Stack Overflow), but got no response. This is functionality that I can’t make rhyme or reason of. I want to u…

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## [What are JSON prototypes?](https://discourse.bokeh.org/t/what-are-json-prototypes/10435)

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**Author:** [@Kewal\_Bajaj](https://discourse.bokeh.org/u/Kewal_Bajaj)\
**Replies:** 1\
**Last updated:** [May 8, 2023, 4:48pm UTC](https://discourse.bokeh.org/t/what-are-json-prototypes/10435 "2023-05-08T16:48:23Z")

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I have been trying to learn bokeh recently and in the course I want to clear few confusions as they have not been documented anywhere (or atleast I could not find it) What is JSON Prototypes for some classes in bokeh.m…

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## [Implementing Sticky Hover Tool in Bokeh](https://discourse.bokeh.org/t/implementing-sticky-hover-tool-in-bokeh/10378)

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**Author:** [@Ofir](https://discourse.bokeh.org/u/Ofir)\
**Replies:** 1\
**Last updated:** [April 24, 2023, 2:48pm UTC](https://discourse.bokeh.org/t/implementing-sticky-hover-tool-in-bokeh/10378 "2023-04-24T14:48:56Z")

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Hey, I would like to restart a discussion about the possibility of making a sticky hover tool in Bokeh. After researching and reading through previous discussions in the forums, it seems that the implementation of the I…

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## [Hover color sync between line and scatter plot](https://discourse.bokeh.org/t/hover-color-sync-between-line-and-scatter-plot/10359)

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**Author:** [@Charalampos\_Bekiaris](https://discourse.bokeh.org/u/Charalampos_Bekiaris)\
**Replies:** 4\
**Last updated:** [April 18, 2023, 1:52pm UTC](https://discourse.bokeh.org/t/hover-color-sync-between-line-and-scatter-plot/10359 "2023-04-18T13:52:43Z")

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Hello everyone! I am building a data analysis app, for viewing data collected by sensors in a formula-like vehicle during the race. I would like to do a line plot (of a sensor reading) and a scatter plot of the logged g…

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## [I want to use hover(tooltips), but unexpected result appear](https://discourse.bokeh.org/t/i-want-to-use-hover-tooltips-but-unexpected-result-appear/10327)

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**Author:** [@sks020k](https://discourse.bokeh.org/u/sks020k)\
**Replies:** 3\
**Last updated:** [April 11, 2023, 3:41am UTC](https://discourse.bokeh.org/t/i-want-to-use-hover-tooltips-but-unexpected-result-appear/10327 "2023-04-11T03:41:14Z")

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hello. I am in the process of creating an hbar. I tried to use tooltips so that the y value and the right value of the hbar come out when I hover over the graph, but as shown in the picture, type:??? value:??? is display…

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## [HoverTool : One hover tool for two CDS that have identical column names to each other](https://discourse.bokeh.org/t/hovertool-one-hover-tool-for-two-cds-that-have-identical-column-names-to-each-other/10259)

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**Author:** [@Omi](https://discourse.bokeh.org/u/Omi)\
**Replies:** 2\
**Last updated:** [March 30, 2023, 6:41am UTC](https://discourse.bokeh.org/t/hovertool-one-hover-tool-for-two-cds-that-have-identical-column-names-to-each-other/10259 "2023-03-30T06:41:24Z")

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Hi, I have two CDS, each CDS has columns “Timestamp”, “x” and “y”. The default hover tool shows the following tooltip. However, I want to show a single tooltip that has “Timestamp \[CDS1\]”, “x \[CDS1\]”, “y \[CDS1\]”, “T…

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## [Client-side Molecular Structure Generation on Hover](https://discourse.bokeh.org/t/client-side-molecular-structure-generation-on-hover/10078)

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**Author:** [@rwilson](https://discourse.bokeh.org/u/rwilson)\
**Replies:** 6\
**Last updated:** [February 27, 2023, 9:20am UTC](https://discourse.bokeh.org/t/client-side-molecular-structure-generation-on-hover/10078 "2023-02-27T09:20:21Z")

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Hi Community, I’m attempting to use Bokeh to create plots annotated with tooltip chemical structures in Jupyter notebooks. Because the number of plot elements can be extremely high, and molecular structure generation fr…

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## [Is it possible to customize image display for mouse hovering up?](https://discourse.bokeh.org/t/is-it-possible-to-customize-image-display-for-mouse-hovering-up/9820)

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**Author:** [@xinwei-zhuang](https://discourse.bokeh.org/u/xinwei-zhuang)\
**Replies:** 2\
**Last updated:** [December 9, 2022, 2:21am UTC](https://discourse.bokeh.org/t/is-it-possible-to-customize-image-display-for-mouse-hovering-up/9820 "2022-12-09T02:21:43Z")

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I have a dense graph, but similar to the source you provided here. when I hover on top of multiple points, it will show images in a strip (as seen below). the current code I’m using within the tooptips are TOOLTIPS …

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