[BUG]: barmode="group" not working with second y axis #5582

Activity

1. inferrna

   added

   bugsomething brokensomething broken

   on Apr 23, 2026
2. camdecoster commented on Apr 24, 2026

   

   camdecoster

   on Apr 24, 2026

   Contributor

   More actions

   Thank you for the report. Our team will take a look and follow up.
3. camdecoster

   assigned

   emilykl

   on Apr 24, 2026
4. emilykl commented on Jun 2, 2026

   

   emilykl

   on Jun 2, 2026

   Contributor

   More actions

   Hi @inferrna, thanks for the report, and apologies for the delayed follow-up. It seems that bar traces associated with different y-axes aren't automatically recognized as part of the same group, which I agree isn't the ideal behaviour.

   As a workaround, you can set the offsetgroup property of each trace to a different value, which will force Plotly to treat them as individual members of a bar group. For your code:

   import plotly.graph_objects as go
   
   def bar_chart_with_error_bars():
       # Trace C
       trace_c = go.Bar(
           x=["Trial 1", "Trial 2", "Trial 3"],
           y=[3, 6, 4],
           name="Trace C",
           error_y=dict(
               type="data",
               array=[1, 0.5, 1.5]
           ),
           offsetgroup=1,                                  #  added
   
       )
   
       # Trace E (secondary y-axis)
       trace_e = go.Bar(
           x=["Trial 1", "Trial 2", "Trial 3"],
           y=[400, 700, 300],
           name="Trace E",
           yaxis="y2",
           error_y=dict(
               type="data",
               array=[50, 100, 200]
           ),
           offsetgroup=2,                                  #  added
       )
   
       # Layout
       layout = go.Layout(
           barmode="group",
           yaxis=dict(title="Trace C"),
           yaxis2=dict(
               title="Trace E",
               overlaying="y",
               side="right"
           )
       )
   
       # Create figure
       fig = go.Figure(data=[trace_c, trace_e], layout=layout)
   
       # Save to HTML
       fig.write_html("/tmp/trials.html")
   
   
   # Call the function
   bar_chart_with_error_bars()

   which produces this result:

   
5. emilykl

   added

   P3backlogbacklog

   size: 3

   on Jul 30, 2026
6. emilykl

   removed their assignment

   on Jul 30, 2026