Merge pull request #5686 from plotly/fix-bad-default-zoom-5450

Fix bad default zoom in Plotly Express map functions

Author: emilykl

CHANGELOG.md

@@ -4,6 +4,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Fixed
+- Improve `px.*_map()` auto-fitting behavior when `zoom` and `center` are not specified [[#5686](https://github.com/plotly/plotly.py/pull/5686)]
+
 
 ## [7.0.0rc0] - 2026-07-29
 

plotly/express/_chart_types.py

@@ -1258,7 +1258,7 @@ def scatter_map(
     color_continuous_midpoint=None,
     opacity=None,
     size_max=None,
-    zoom=8,
+    zoom=None,
     center=None,
     map_style=None,
     title=None,
@@ -1296,7 +1296,7 @@ def choropleth_map(
     range_color=None,
     color_continuous_midpoint=None,
     opacity=None,
-    zoom=8,
+    zoom=None,
     center=None,
     map_style=None,
     title=None,
@@ -1331,7 +1331,7 @@ def density_map(
     range_color=None,
     color_continuous_midpoint=None,
     opacity=None,
-    zoom=8,
+    zoom=None,
     center=None,
     map_style=None,
     radius=None,
@@ -1369,7 +1369,7 @@ def line_map(
     labels=None,
     color_discrete_sequence=None,
     color_discrete_map=None,
-    zoom=8,
+    zoom=None,
     center=None,
     map_style=None,
     title=None,

plotly/express/_core.py

@@ -793,14 +793,8 @@ def configure_3d_axes(args, fig, orders):
 
 
 def configure_map(args, fig, orders):
-    center = args["center"]
-    if not center and "lat" in args and "lon" in args:
-        center = dict(
-            lat=args["data_frame"][args["lat"]].mean(),
-            lon=args["data_frame"][args["lon"]].mean(),
-        )
     fig.update_maps(
-        center=center,
+        center=args["center"],
         zoom=args["zoom"],
         style=args["map_style"],
     )

plotly/express/_doc.py

@@ -500,7 +500,12 @@
         "In `'overlay'` mode, strips are on drawn top of one another.",
         "In `'group'` mode, strips are placed beside each other.",
     ],
-    zoom=["int (default `8`)", "Between 0 and 20.", "Sets map zoom level."],
+    zoom=[
+        "int (default `None`)",
+        "Between 0 and 20.",
+        "Sets initial map zoom level. Higher values are more zoomed-in.",
+        "If not provided, the map will select its own zoom level.",
+    ],
     orientation=[
         "str, one of `'h'` for horizontal or `'v'` for vertical. ",
         "(default `'v'` if `x` and `y` are provided and both continuous or both categorical, ",

tests/percy/plotly-express.py

@@ -386,7 +386,6 @@
     size="car_hours",
     color_continuous_scale=px.colors.cyclical.IceFire,
     size_max=15,
-    zoom=10,
 )
 fig.write_html(os.path.join(dir_name, "scatter_map.html"))