diff --git a/abstutil/src/cli.rs b/abstutil/src/cli.rs
index e4ac0082f5..0f002578b0 100644
--- a/abstutil/src/cli.rs
+++ b/abstutil/src/cli.rs
@@ -10,7 +10,7 @@ pub struct CmdArgs {
 }
 
 impl CmdArgs {
-    /// On native, initialize with real flags. On web, always empty.
+    /// On native, initialize with real flags. On web, transform URL query parameters into flags.
     ///
     /// Calling this has the side-effect of initializing logging on both native and web. This
     /// should probably be done independently, but for the moment, every app wants both.
diff --git a/map_gui/Cargo.toml b/map_gui/Cargo.toml
index f5009b5763..61fc7529d3 100644
--- a/map_gui/Cargo.toml
+++ b/map_gui/Cargo.toml
@@ -7,8 +7,6 @@ edition = "2018"
 [features]
 native = ["reqwest", "tokio"]
 wasm = ["js-sys", "wasm-bindgen", "wasm-bindgen-futures", "web-sys"]
-# Just a marker to not use localhost URLs
-wasm_s3 = []
 # A marker to use a named release from S3 instead of dev for updating files
 release_s3 = []
 
diff --git a/map_gui/src/load.rs b/map_gui/src/load.rs
index e60420f9b4..16f03c1785 100644
--- a/map_gui/src/load.rs
+++ b/map_gui/src/load.rs
@@ -148,21 +148,22 @@ mod wasm_loader {
             path: String,
             on_load: Box<dyn FnOnce(&mut EventCtx, &mut A, &mut Timer, Result<T>) -> Transition<A>>,
         ) -> Box<dyn State<A>> {
-            // Note that files are only gzipepd on S3. When running locally, we just symlink the
-            // data/ directory, where files aren't compressed.
-            let url = if cfg!(feature = "wasm_s3") {
-                // Anytime data with a new binary format is uploaded, the web client has to be
-                // re-deployed too
-                format!(
-                    "http://abstreet.s3-website.us-east-2.amazonaws.com/dev/data/{}.gz",
-                    path.strip_prefix(&abstio::path("")).unwrap()
-                )
-            } else {
-                format!(
-                    "http://0.0.0.0:8000/{}",
-                    path.strip_prefix(&abstio::path("")).unwrap()
-                )
-            };
+            // The current URL is of the index.html page. We can find the data directory relative
+            // to that.
+            let base_url = get_base_url().unwrap();
+            let file_path = path.strip_prefix(&abstio::path("")).unwrap();
+            // Note that files are gzipped on S3 and other deployments. When running locally, we
+            // just symlink the data/ directory, where files aren't compressed.
+            let url =
+                if base_url.contains("http://0.0.0.0") || base_url.contains("http://localhost") {
+                    format!("{}/{}", base_url, file_path)
+                } else if base_url.contains("abstreet.s3-website") {
+                    // The directory structure on S3 is a little weird -- the base directory has
+                    // data/ alongside game/, fifteen_min/, etc.
+                    format!("{}/../data/{}.gz", base_url, file_path)
+                } else {
+                    format!("{}/{}.gz", base_url, file_path)
+                };
 
             // Make the HTTP request nonblockingly. When the response is received, send it through
             // the channel.
@@ -249,6 +250,23 @@ mod wasm_loader {
             self.panel.draw(g);
         }
     }
+
+    /// Returns the base URL where the game is running, excluding query parameters and the
+    /// implicit index.html that might be there.
+    fn get_base_url() -> Result<String> {
+        let window = web_sys::window().ok_or(anyhow!("no window?"))?;
+        let url = window.location().href().map_err(|err| {
+            anyhow!(err
+                .as_string()
+                .unwrap_or("window.location.href failed".to_string()))
+        })?;
+        // Consider using a proper url parsing crate. This works fine for now, though.
+        let url = url.split("?").next().ok_or(anyhow!("empty URL?"))?;
+        Ok(url
+            .trim_end_matches("index.html")
+            .trim_end_matches("/")
+            .to_string())
+    }
 }
 
 pub struct FutureLoader<A, T>
diff --git a/release/deploy_actdev.sh b/release/deploy_actdev.sh
index 8a571c2794..e423ceb027 100755
--- a/release/deploy_actdev.sh
+++ b/release/deploy_actdev.sh
@@ -5,7 +5,7 @@ set -e
 
 mkdir -p abst_actdev
 cd game
-wasm-pack build --release --target web -- --no-default-features --features wasm,map_gui/wasm_s3
+wasm-pack build --release --target web -- --no-default-features --features wasm
 # Temporarily remove the symlink to the data directory
 rm -f pkg/system
 # Expand symlinks
@@ -22,4 +22,6 @@ done
 cp -Rv data/system/study_areas abst_actdev/system
 gzip `find abst_actdev/ | grep bin | xargs`
 
-echo "Go upload abst_actdev/ somewhere"
+zip -r abst_actdev abst_actdev
+rm -rf abst_actdev
+echo "Go upload abst_actdev.zip to https://github.com/cyipt/actdev/releases"
diff --git a/release/deploy_web.sh b/release/deploy_web.sh
index 696e6eb1cf..89db30116f 100755
--- a/release/deploy_web.sh
+++ b/release/deploy_web.sh
@@ -7,7 +7,7 @@ set -e
 # The parking mapper doesn't work on WASM yet, so don't include it
 for tool in game santa fifteen_min osm_viewer; do
 	cd $tool
-	wasm-pack build --release --target web -- --no-default-features --features wasm,map_gui/wasm_s3
+	wasm-pack build --release --target web -- --no-default-features --features wasm
 	cd pkg
 	# Temporarily remove the symlink to the data directory; it's uploaded separately by the updater tool
 	rm -f system