diff --git a/Cargo.lock b/Cargo.lock
index 11db0f82..30cc4242 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4580,6 +4580,7 @@ dependencies = [
  "vectorcraft-testkit",
  "vectorcraft-text",
  "windows",
+ "winsafe",
 ]
 
 [[package]]
diff --git a/apps/vectorcraft-cli/Cargo.toml b/apps/vectorcraft-cli/Cargo.toml
index 1d0e01ae..c31998d0 100644
--- a/apps/vectorcraft-cli/Cargo.toml
+++ b/apps/vectorcraft-cli/Cargo.toml
@@ -26,6 +26,12 @@ vectorcraft-text = { workspace = true }
 serde_json = { workspace = true }
 log = { workspace = true }
 
+# `perf` on Windows (src/perf.rs) reads how busy the processors are (GetSystemTimes) and this
+# process's working set (GetProcessMemoryInfo) through winsafe's safe wrappers over Win32 (MIT),
+# which the desktop app's src/gpu.rs also uses.
+[target.'cfg(windows)'.dependencies]
+winsafe = { version = "0.0.29", default-features = false, features = ["kernel", "psapi"] }
+
 # DirectWrite's system font collection (the desktop app's src/system_fonts.rs, shared): fonts that
 # font services such as Adobe Fonts load in place (#579). MIT OR Apache-2.0.
 [target.'cfg(all(windows, not(target_vendor = "win7")))'.dependencies]
diff --git a/apps/vectorcraft-cli/src/main.rs b/apps/vectorcraft-cli/src/main.rs
index f5dd5467..8c595421 100644
--- a/apps/vectorcraft-cli/src/main.rs
+++ b/apps/vectorcraft-cli/src/main.rs
@@ -7,7 +7,7 @@
 //! vectorcraft-cli convert IN OUT [--scale 2] [--artboard 0 | --range 1-3,5] [--outline-text] [--decimals N] [--replace-lossy] [--editing-data]
 //! vectorcraft-cli info FILE
 //! vectorcraft-cli bench FILE [--size 2880x1800] [--iters 5]
-//! vectorcraft-cli perf [--paths 50000]
+//! vectorcraft-cli perf [--paths 50000] [--deep]
 //! ```
 // Denied, not forbidden: the font listers shared with the desktop app allow it for their
 // DirectWrite (Windows) and CoreText (macOS) calls, and nothing else may.
@@ -104,9 +104,11 @@ USAGE:
       Render FILE (any readable format) fitted to WxH (default 2880x1800) and print ms per frame
       (warm), multithreaded and single-threaded.
 
-  vectorcraft-cli perf [--paths N]
-      Check the performance budgets (render, pan, hit test, save/load, SVG, Pathfinder) on a
-      synthetic N-path document (default 50000). Exits non-zero if a budget is exceeded.
+  vectorcraft-cli perf [--paths N] [--deep]
+      Check the performance budgets (render, pan, hit test, save/load, SVG, Pathfinder, handle
+      and segment drags) on a synthetic N-path document (default 50000). Exits non-zero if a
+      budget is exceeded, unless the report says the machine is busy. --deep also times work with
+      no budget yet and prints memory use (the working set on Windows).
 ";
 
 /// The usage text plus the formats `document.open` reads and `document.export` writes.
diff --git a/apps/vectorcraft-cli/src/perf.rs b/apps/vectorcraft-cli/src/perf.rs
index 97cd0647..0a59ed69 100644
--- a/apps/vectorcraft-cli/src/perf.rs
+++ b/apps/vectorcraft-cli/src/perf.rs
@@ -1,7 +1,8 @@
 //! `vectorcraft-cli perf`: the performance budgets (plan §4) measured on a synthetic document.
 //!
-//! Each row is the median of several runs. Timings are wall-clock: on a busy machine (load
-//! average above the core count) they are noise, and the report says so.
+//! Each row is the median of several runs. Timings are wall-clock: on a busy machine (a load
+//! average above three quarters of the cores, or on Windows more than three quarters of the
+//! cores busy over a second) they are noise, and the report says so.
 
 use std::time::Instant;
 
@@ -61,6 +62,7 @@ fn median_ms(runs: usize, mut f: impl FnMut()) -> f64 {
 }
 
 /// 1-minute load average (macOS / Linux), if available.
+#[cfg(not(windows))]
 fn load_average() -> Option<f64> {
     let out = std::process::Command::new("sysctl").args(["-n", "vm.loadavg"]).output().ok().filter(|o| o.status.success());
     let text = match out {
@@ -70,6 +72,27 @@ fn load_average() -> Option<f64> {
     text.split_whitespace().map(|t| t.trim_matches(|c| c == '{' || c == '}')).find_map(|t| t.parse().ok())
 }
 
+/// The cores busy on average over one second (Windows), if available: the share of the
+/// processors' time that `GetSystemTimes` reports as kernel or user time but not as idle time,
+/// times `cores`. A load average also counts the threads waiting for a core.
+#[cfg(windows)]
+fn busy_cores(cores: usize) -> Option<f64> {
+    let times = || winsafe::GetSystemTimes().ok().map(|(idle, kernel, user)| [idle, kernel, user].map(u64::from));
+    let before = times()?;
+    std::thread::sleep(std::time::Duration::from_secs(1));
+    busy_share(before, times()?).map(|share| share * cores as f64)
+}
+
+/// The share of the processors' time between two `[idle, kernel, user]` readings of
+/// `GetSystemTimes` that was busy (kernel time includes idle time). It is None when no time
+/// passed, a time went back, or the idle time exceeds the kernel and user time.
+#[cfg(any(windows, test))]
+fn busy_share([idle0, kernel0, user0]: [u64; 3], [idle1, kernel1, user1]: [u64; 3]) -> Option<f64> {
+    let total = kernel1.checked_sub(kernel0)?.checked_add(user1.checked_sub(user0)?)?;
+    let busy = total.checked_sub(idle1.checked_sub(idle0)?)?;
+    (total > 0).then(|| busy as f64 / total as f64)
+}
+
 /// Milliseconds per pointer move of a Direct Selection drag of a handle, then of a segment, of a
 /// 5,000-anchor wave of smooth anchors added on top of the synthetic `n`-path document.
 fn edit_drags(n: usize) -> Result<(f64, f64), String> {
@@ -114,12 +137,21 @@ fn edit_drags(n: usize) -> Result<(f64, f64), String> {
 }
 
 /// Resident memory of this process in MB (`ps`), if available.
+#[cfg(not(windows))]
 fn rss_mb() -> Option<f64> {
     let pid = std::process::id().to_string();
     let out = std::process::Command::new("ps").args(["-o", "rss=", "-p", &pid]).output().ok().filter(|o| o.status.success())?;
     String::from_utf8_lossy(&out.stdout).trim().parse::<f64>().ok().map(|kb| kb / 1024.0)
 }
 
+/// The working set of this process in MB (`GetProcessMemoryInfo`), if available: its pages that
+/// are in physical memory, the figure `ps` reports as resident memory elsewhere.
+#[cfg(windows)]
+fn rss_mb() -> Option<f64> {
+    let counters = winsafe::HPROCESS::GetCurrentProcess().GetProcessMemoryInfo().ok()?;
+    Some(counters.WorkingSetSize as f64 / (1024.0 * 1024.0))
+}
+
 /// `--deep`: tracked rows (no budget yet) for work the budgets above don't reach: editing a whole
 /// selection, live effects, every Pathfinder operation, typing in a long story, and memory.
 fn deep(n: usize) -> Result<(), String> {
@@ -243,8 +275,10 @@ fn deep(n: usize) -> Result<(), String> {
     for (name, ms) in &rows {
         outln!("  {name:<52} {ms:>10.2} ms");
     }
+    // `rss_mb` reads the working set on Windows.
+    let memory = if cfg!(windows) { "working set" } else { "memory" };
     for (what, mb) in &mem {
-        outln!("  memory {what:<45} {mb:>8.0} MB");
+        outln!("  {:<52} {mb:>8.0} MB", format!("{memory} {what}"));
     }
     Ok(())
 }
@@ -261,8 +295,12 @@ pub fn run(args: &[String]) -> Result<(), String> {
         }
     }
     let cores = std::thread::available_parallelism().map_or(1, |c| c.get());
-    let load = load_average();
-    outln!("VectorCraft performance budgets — {n} paths, {cores} cores, load average {}", load.map_or("?".into(), |l| format!("{l:.1}")));
+    // The figure is the 1-minute load average, or on Windows the cores busy over one second.
+    #[cfg(not(windows))]
+    let (load, label) = (load_average(), "load average");
+    #[cfg(windows)]
+    let (load, label) = (busy_cores(cores), "cores busy");
+    outln!("VectorCraft performance budgets — {n} paths, {cores} cores, {label} {}", load.map_or("?".into(), |l| format!("{l:.1}")));
     let noisy = load.is_some_and(|l| l > cores as f64 * 0.75);
     if noisy {
         outln!("WARNING: the machine is busy; wall-clock timings below are not trustworthy.");
@@ -358,3 +396,38 @@ pub fn run(args: &[String]) -> Result<(), String> {
         _ => Err(format!("{over} budget(s) exceeded")),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn busy_share_leaves_out_idle_time() {
+        // In one second four processors log 40,000,000 ticks of 100 ns of kernel and user time,
+        // 10,000,000 of them idle.
+        assert_eq!(busy_share([7, 100, 50], [10_000_007, 25_000_100, 15_000_050]), Some(0.75));
+        // There is no share when no time passed, a time went back, or the idle time exceeds the
+        // kernel and user time.
+        assert_eq!(busy_share([7, 100, 50], [7, 100, 50]), None);
+        assert_eq!(busy_share([7, 100, 50], [8, 99, 60]), None);
+        assert_eq!(busy_share([0, 0, 0], [30, 10, 10]), None);
+    }
+
+    /// On Windows `busy_cores` gives a number between 0 and the cores.
+    #[cfg(windows)]
+    #[test]
+    fn windows_reads_how_many_cores_are_busy() {
+        let cores = std::thread::available_parallelism().map_or(1, |c| c.get());
+        let busy = busy_cores(cores);
+        assert!(busy.is_some_and(|b| (0.0..=cores as f64).contains(&b)), "{busy:?} of {cores}");
+    }
+
+    /// On Windows `rss_mb` gives this process's working set: more than 0 MB and less than
+    /// 10,000 MB.
+    #[cfg(windows)]
+    #[test]
+    fn windows_reads_the_working_set() {
+        let mb = rss_mb();
+        assert!(mb.is_some_and(|mb| mb > 0.0 && mb < 10_000.0), "{mb:?}");
+    }
+}
diff --git a/apps/vectorcraft-cli/tests/fileio.rs b/apps/vectorcraft-cli/tests/fileio.rs
index 36c903b8..f23ab514 100644
--- a/apps/vectorcraft-cli/tests/fileio.rs
+++ b/apps/vectorcraft-cli/tests/fileio.rs
@@ -83,6 +83,12 @@ fn help_lists_readable_formats() {
     assert!(out.contains("Readable formats: .vectorcraft") && out.contains(".ait") && out.contains(".webp"), "{out}");
 }
 
+#[test]
+fn help_lists_perf_deep() {
+    let out = ok(&["--help"]);
+    assert!(out.contains("vectorcraft-cli perf [--paths N] [--deep]") && out.contains("--deep also times"), "{out}");
+}
+
 /// `info` reports the import warnings: an EPS read only up to an error names it.
 #[test]
 fn info_reports_why_an_eps_read_partly() {