diff --git a/datasette/cli.py b/datasette/cli.py
index 2fa039a0..42b5c115 100644
--- a/datasette/cli.py
+++ b/datasette/cli.py
@@ -191,7 +191,7 @@ def plugins(all, plugins_dir):
     help="Path to JSON/YAML file containing metadata to publish",
 )
 @click.option("--extra-options", help="Extra options to pass to datasette serve")
-@click.option("--branch", help="Install datasette from a GitHub branch e.g. master")
+@click.option("--branch", help="Install datasette from a GitHub branch e.g. main")
 @click.option(
     "--template-dir",
     type=click.Path(exists=True, file_okay=False, dir_okay=True),
diff --git a/datasette/publish/common.py b/datasette/publish/common.py
index b6570290..29665eb3 100644
--- a/datasette/publish/common.py
+++ b/datasette/publish/common.py
@@ -19,7 +19,7 @@ def add_common_publish_arguments_and_options(subcommand):
                 "--extra-options", help="Extra options to pass to datasette serve"
             ),
             click.option(
-                "--branch", help="Install datasette from a GitHub branch e.g. master"
+                "--branch", help="Install datasette from a GitHub branch e.g. main"
             ),
             click.option(
                 "--template-dir",
diff --git a/datasette/templates/patterns.html b/datasette/templates/patterns.html
index 984c1bf6..3f9b5a16 100644
--- a/datasette/templates/patterns.html
+++ b/datasette/templates/patterns.html
@@ -70,10 +70,10 @@
     </div>
     <p>
     Data license:
-            <a href="https://github.com/simonw/datasette/blob/master/LICENSE">Apache License 2.0</a>
+            <a href="https://github.com/simonw/datasette/blob/main/LICENSE">Apache License 2.0</a>
     &middot;
         Data source:
-            <a href="https://github.com/simonw/datasette/blob/master/tests/fixtures.py">
+            <a href="https://github.com/simonw/datasette/blob/main/tests/fixtures.py">
         tests/fixtures.py</a>
     &middot;
         About:
@@ -118,10 +118,10 @@
     </div>
     <p>
     Data license:
-            <a href="https://github.com/simonw/datasette/blob/master/LICENSE">Apache License 2.0</a>
+            <a href="https://github.com/simonw/datasette/blob/main/LICENSE">Apache License 2.0</a>
     &middot;
         Data source:
-            <a href="https://github.com/simonw/datasette/blob/master/tests/fixtures.py">
+            <a href="https://github.com/simonw/datasette/blob/main/tests/fixtures.py">
         tests/fixtures.py</a>
     &middot;
         About:
@@ -177,10 +177,10 @@
 
     <p>
     Data license:
-            <a href="https://github.com/simonw/datasette/blob/master/LICENSE">Apache License 2.0</a>
+            <a href="https://github.com/simonw/datasette/blob/main/LICENSE">Apache License 2.0</a>
     &middot;
         Data source:
-            <a href="https://github.com/simonw/datasette/blob/master/tests/fixtures.py">
+            <a href="https://github.com/simonw/datasette/blob/main/tests/fixtures.py">
         tests/fixtures.py</a>
     &middot;
         About:
@@ -478,10 +478,10 @@
 
 <footer class="ft">Powered by <a href="https://datasette.io/" title="Datasette v0+unknown">Datasette</a>
     &middot; Data license:
-            <a href="https://github.com/simonw/datasette/blob/master/LICENSE">Apache License 2.0</a>
+            <a href="https://github.com/simonw/datasette/blob/main/LICENSE">Apache License 2.0</a>
     &middot;
         Data source:
-            <a href="https://github.com/simonw/datasette/blob/master/tests/fixtures.py">
+            <a href="https://github.com/simonw/datasette/blob/main/tests/fixtures.py">
         tests/fixtures.py</a>
     &middot;
         About:
diff --git a/docs/contributing.rst b/docs/contributing.rst
index 2cf641fd..7e16280b 100644
--- a/docs/contributing.rst
+++ b/docs/contributing.rst
@@ -10,7 +10,7 @@ This document describes how to contribute to Datasette core. You can also contri
 General guidelines
 ------------------
 
-* **master should always be releasable**. Incomplete features should live in branches. This ensures that any small bug fixes can be quickly released.
+* **main should always be releasable**. Incomplete features should live in branches. This ensures that any small bug fixes can be quickly released.
 * **The ideal commit** should bundle together the implementation, unit tests and associated documentation updates. The commit message should link to an associated issue.
 * **New plugin hooks** should only be shipped if accompanied by a separate release of a non-demo plugin that uses them.
 
diff --git a/docs/custom_templates.rst b/docs/custom_templates.rst
index a7236873..efb5b842 100644
--- a/docs/custom_templates.rst
+++ b/docs/custom_templates.rst
@@ -303,7 +303,7 @@ from the default template.
 
 The ``_table.html`` template is included by both the row and the table pages,
 and a list of rows. The default ``_table.html`` template renders them as an
-HTML template and `can be seen here <https://github.com/simonw/datasette/blob/master/datasette/templates/_table.html>`_.
+HTML template and `can be seen here <https://github.com/simonw/datasette/blob/main/datasette/templates/_table.html>`_.
 
 You can provide a custom template that applies to all of your databases and
 tables, or you can provide custom templates for specific tables using the
diff --git a/docs/datasette-package-help.txt b/docs/datasette-package-help.txt
index ab5cf8a3..5f5ce070 100644
--- a/docs/datasette-package-help.txt
+++ b/docs/datasette-package-help.txt
@@ -10,7 +10,7 @@ Options:
 
   -m, --metadata FILENAME   Path to JSON/YAML file containing metadata to publish
   --extra-options TEXT      Extra options to pass to datasette serve
-  --branch TEXT             Install datasette from a GitHub branch e.g. master
+  --branch TEXT             Install datasette from a GitHub branch e.g. main
   --template-dir DIRECTORY  Path to directory containing custom templates
   --plugins-dir DIRECTORY   Path to directory containing custom plugins
   --static MOUNT:DIRECTORY  Serve static files from this directory at /MOUNT/...
diff --git a/docs/datasette-publish-cloudrun-help.txt b/docs/datasette-publish-cloudrun-help.txt
index 8cf293d9..c706d921 100644
--- a/docs/datasette-publish-cloudrun-help.txt
+++ b/docs/datasette-publish-cloudrun-help.txt
@@ -5,7 +5,7 @@ Usage: datasette publish cloudrun [OPTIONS] [FILES]...
 Options:
   -m, --metadata FILENAME         Path to JSON/YAML file containing metadata to publish
   --extra-options TEXT            Extra options to pass to datasette serve
-  --branch TEXT                   Install datasette from a GitHub branch e.g. master
+  --branch TEXT                   Install datasette from a GitHub branch e.g. main
   --template-dir DIRECTORY        Path to directory containing custom templates
   --plugins-dir DIRECTORY         Path to directory containing custom plugins
   --static MOUNT:DIRECTORY        Serve static files from this directory at /MOUNT/...
diff --git a/docs/datasette-publish-heroku-help.txt b/docs/datasette-publish-heroku-help.txt
index 991bd8f4..c4b852de 100644
--- a/docs/datasette-publish-heroku-help.txt
+++ b/docs/datasette-publish-heroku-help.txt
@@ -5,7 +5,7 @@ Usage: datasette publish heroku [OPTIONS] [FILES]...
 Options:
   -m, --metadata FILENAME         Path to JSON/YAML file containing metadata to publish
   --extra-options TEXT            Extra options to pass to datasette serve
-  --branch TEXT                   Install datasette from a GitHub branch e.g. master
+  --branch TEXT                   Install datasette from a GitHub branch e.g. main
   --template-dir DIRECTORY        Path to directory containing custom templates
   --plugins-dir DIRECTORY         Path to directory containing custom plugins
   --static MOUNT:DIRECTORY        Serve static files from this directory at /MOUNT/...
diff --git a/docs/plugin_hooks.rst b/docs/plugin_hooks.rst
index 23e57278..0a176add 100644
--- a/docs/plugin_hooks.rst
+++ b/docs/plugin_hooks.rst
@@ -304,7 +304,7 @@ publish_subcommand(publish)
 This hook allows you to create new providers for the ``datasette publish``
 command. Datasette uses this hook internally to implement the default ``now``
 and ``heroku`` subcommands, so you can read
-`their source <https://github.com/simonw/datasette/tree/master/datasette/publish>`_
+`their source <https://github.com/simonw/datasette/tree/main/datasette/publish>`_
 to see examples of this hook in action.
 
 Let's say you want to build a plugin that adds a ``datasette publish my_hosting_provider --api_key=xxx mydatabase.db`` publish command. Your implementation would start like this:
@@ -641,7 +641,7 @@ Each Facet subclass implements a new type of facet operation. The class should l
 
             return facet_results, facets_timed_out
 
-See `datasette/facets.py <https://github.com/simonw/datasette/blob/master/datasette/facets.py>`__ for examples of how these classes can work.
+See `datasette/facets.py <https://github.com/simonw/datasette/blob/main/datasette/facets.py>`__ for examples of how these classes can work.
 
 The plugin hook can then be used to register the new facet class like this:
 
diff --git a/docs/publish.rst b/docs/publish.rst
index d5015e21..780933fc 100644
--- a/docs/publish.rst
+++ b/docs/publish.rst
@@ -78,7 +78,7 @@ Publishing to Vercel
     pip install datasette-publish-vercel
     datasette publish vercel mydatabase.db --project my-database-project
 
-Not every feature is supported: consult the `datasette-publish-vercel README <https://github.com/simonw/datasette-publish-vercel/blob/master/README.md>`__ for more details.
+Not every feature is supported: consult the `datasette-publish-vercel README <https://github.com/simonw/datasette-publish-vercel/blob/main/README.md>`__ for more details.
 
 .. _publish_fly:
 
@@ -92,7 +92,7 @@ Publishing to Fly
     pip install datasette-publish-fly
     datasette publish fly mydatabase.db
 
-Consult the `datasette-publish-fly README <https://github.com/simonw/datasette-publish-fly/blob/master/README.md>`__ for more details.
+Consult the `datasette-publish-fly README <https://github.com/simonw/datasette-publish-fly/blob/main/README.md>`__ for more details.
 
 .. _publish_custom_metadata_and_plugins:
 
diff --git a/docs/spatialite.rst b/docs/spatialite.rst
index 0871d72d..234d97e5 100644
--- a/docs/spatialite.rst
+++ b/docs/spatialite.rst
@@ -53,7 +53,7 @@ If you are unsure of the location of the module, try running ``locate mod_spatia
 Building SpatiaLite from source
 -------------------------------
 
-The packaged versions of SpatiaLite usually provide SpatiaLite 4.3.0a. For an example of how to build the most recent unstable version, 4.4.0-RC0 (which includes the powerful `VirtualKNN module <https://www.gaia-gis.it/fossil/libspatialite/wiki?name=KNN>`_), take a look at the `Datasette Dockerfile <https://github.com/simonw/datasette/blob/master/Dockerfile>`_.
+The packaged versions of SpatiaLite usually provide SpatiaLite 4.3.0a. For an example of how to build the most recent unstable version, 4.4.0-RC0 (which includes the powerful `VirtualKNN module <https://www.gaia-gis.it/fossil/libspatialite/wiki?name=KNN>`_), take a look at the `Datasette Dockerfile <https://github.com/simonw/datasette/blob/main/Dockerfile>`_.
 
 Spatial indexing latitude/longitude columns
 ===========================================
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 2fd8e9cb..0a721d3a 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -283,9 +283,9 @@ METADATA = {
     "title": "Datasette Fixtures",
     "description_html": 'An example SQLite database demonstrating Datasette. <a href="/login-as-root">Sign in as root user</a>',
     "license": "Apache License 2.0",
-    "license_url": "https://github.com/simonw/datasette/blob/master/LICENSE",
+    "license_url": "https://github.com/simonw/datasette/blob/main/LICENSE",
     "source": "tests/fixtures.py",
-    "source_url": "https://github.com/simonw/datasette/blob/master/tests/fixtures.py",
+    "source_url": "https://github.com/simonw/datasette/blob/main/tests/fixtures.py",
     "about": "About Datasette",
     "about_url": "https://github.com/simonw/datasette",
     "extra_css_urls": ["/static/extra-css-urls.css"],
diff --git a/tests/test_html.py b/tests/test_html.py
index 3482ec35..9e86ebc2 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -1093,12 +1093,11 @@ def assert_footer_links(soup):
     assert "About Datasette" == about_link.text.strip()
     assert "https://datasette.io/" == datasette_link["href"]
     assert (
-        "https://github.com/simonw/datasette/blob/master/tests/fixtures.py"
+        "https://github.com/simonw/datasette/blob/main/tests/fixtures.py"
         == source_link["href"]
     )
     assert (
-        "https://github.com/simonw/datasette/blob/master/LICENSE"
-        == license_link["href"]
+        "https://github.com/simonw/datasette/blob/main/LICENSE" == license_link["href"]
     )
     assert "https://github.com/simonw/datasette" == about_link["href"]
 
@@ -1513,8 +1512,8 @@ def test_base_url_config(app_client_base_url_prefix, path):
             and href
             not in {
                 "https://datasette.io/",
-                "https://github.com/simonw/datasette/blob/master/LICENSE",
-                "https://github.com/simonw/datasette/blob/master/tests/fixtures.py",
+                "https://github.com/simonw/datasette/blob/main/LICENSE",
+                "https://github.com/simonw/datasette/blob/main/tests/fixtures.py",
                 "/login-as-root",  # Only used for the latest.datasette.io demo
             }
             and not href.startswith("https://plugin-example.datasette.io/")