diff --git a/ios/Sources/WebViewController.swift b/ios/Sources/WebViewController.swift
index 62f2b0b..b046423 100644
--- a/ios/Sources/WebViewController.swift
+++ b/ios/Sources/WebViewController.swift
@@ -56,12 +56,92 @@ final class WebViewController: UIViewController, WKNavigationDelegate {
             self?.setBanner(nil)
         }
         cfg.userContentController.add(bridge, name: Bridge.handlerName)
+        Zoom.install(into: cfg.userContentController)
 
         setUpBanner()
 
         if ServerSettings.isConfigured { load() }
     }
 
+    // MARK: - how big the page is drawn
+
+    /// The page is sized for a phone and for a browser window, and on a Mac -- where the window
+    /// is often two thousand points across -- it reads small. Scaling it here rather than asking
+    /// ipx to carry a text size: the page is right everywhere else, and this is the one place
+    /// that is wrong.
+    enum Zoom {
+        private static let key = "ipx.zoom"
+        static let steps: [Double] = [1.0, 1.15, 1.25, 1.4, 1.6, 1.8, 2.0]
+
+        /// A Mac starts bigger; a phone and an iPad are already right.
+        static var normal: Double {
+            #if targetEnvironment(macCatalyst)
+            return 1.25
+            #else
+            return 1.0
+            #endif
+        }
+
+        static var current: Double {
+            get {
+                let v = UserDefaults.standard.double(forKey: key)
+                return steps.contains(v) ? v : normal
+            }
+            set { UserDefaults.standard.set(newValue, forKey: key) }
+        }
+
+        /// pageZoom alone spilled the page off the screen: ipx's body is `height:100dvh`, and
+        /// WebKit measures dvh against the unzoomed window, so the page laid itself out at the
+        /// window's full size and was then scaled up. A percentage of the root resolves against
+        /// a box that does know about zoom, which is the whole of the fix.
+        /// CSS zoom, not WKWebView.pageZoom. pageZoom scales what is drawn but leaves the
+        /// layout box the size of the window, so ipx's full-height page -- body is 100dvh --
+        /// laid itself out at the window's height and then got scaled past the bottom of it.
+        /// CSS zoom is part of layout, so the page measures itself correctly; body's own width
+        /// and height are divided back out because its containing block is not zoomed.
+        static func script(_ zoom: Double) -> String {
+            let css = zoom == 1
+                ? ""
+                : "body{zoom:\(zoom);width:calc(100%/\(zoom))!important;"
+                  + "height:calc(100dvh/\(zoom))!important}"
+            return "(function(){var id='ipx-zoom';var s=document.getElementById(id);"
+                + "if(!s){s=document.createElement('style');s.id=id;"
+                + "(document.head||document.documentElement).appendChild(s)}"
+                + "s.textContent=\(css.debugDescription)})()"
+        }
+
+        static func install(into controller: WKUserContentController) {
+            controller.addUserScript(WKUserScript(source: script(current),
+                                                  injectionTime: .atDocumentEnd,
+                                                  forMainFrameOnly: true))
+        }
+    }
+
+    override var keyCommands: [UIKeyCommand]? {
+        // The page's own shortcuts are single keys and ignore a modifier, so these do not collide.
+        [
+            UIKeyCommand(title: "Bigger", action: #selector(zoomIn), input: "+", modifierFlags: .command),
+            UIKeyCommand(title: "Bigger", action: #selector(zoomIn), input: "=", modifierFlags: .command),
+            UIKeyCommand(title: "Smaller", action: #selector(zoomOut), input: "-", modifierFlags: .command),
+            UIKeyCommand(title: "Actual Size", action: #selector(zoomReset), input: "0", modifierFlags: .command),
+        ]
+    }
+
+    @objc private func zoomIn() { step(+1) }
+    @objc private func zoomOut() { step(-1) }
+    @objc private func zoomReset() { apply(Zoom.normal) }
+
+    private func step(_ by: Int) {
+        let steps = Zoom.steps
+        let at = steps.firstIndex(of: Zoom.current) ?? 0
+        apply(steps[min(steps.count - 1, max(0, at + by))])
+    }
+
+    private func apply(_ zoom: Double) {
+        Zoom.current = zoom
+        webView.evaluateJavaScript(Zoom.script(zoom))
+    }
+
     // MARK: - which server
 
     /// Shake to change it. There is nowhere on screen to put a button -- the page fills it, and