Windows ARM64

Author: Jarred-Sumner

.buildkite/ci.mjs

@@ -474,7 +474,8 @@ function getBuildCommand(target, options, label) {
 
   if (target.os === "windows" && label === "build-bun") {
     // Only sign release builds, not canary builds (DigiCert charges per signature)
-    const enableSigning = !options.canary ? " -DENABLE_WINDOWS_CODESIGNING=ON" : "";
+    // Skip signing on ARM64 for now — smctl (x64-only) silently fails under emulation
+    const enableSigning = !options.canary && target.arch !== "aarch64" ? " -DENABLE_WINDOWS_CODESIGNING=ON" : "";
     return `bun run build:${buildProfile}${enableSigning}`;
   }
 

README.md

@@ -43,7 +43,7 @@ bunx cowsay 'Hello, world!'   # execute a package
 
 ## Install
 
-Bun supports Linux (x64 & arm64), macOS (x64 & Apple Silicon) and Windows (x64).
+Bun supports Linux (x64 & arm64), macOS (x64 & Apple Silicon) and Windows (x64 & arm64).
 
 > **Linux users** — Kernel version 5.6 or higher is strongly recommended, but the minimum is 5.1.
 

docs/bundler/executables.mdx

@@ -157,6 +157,31 @@ To build for Windows x64:
   </Tab>
 </Tabs>
 
+To build for Windows arm64:
+
+<Tabs>
+  <Tab title="CLI">
+    ```bash icon="terminal" terminal
+    bun build --compile --target=bun-windows-arm64 ./path/to/my/app.ts --outfile myapp
+
+    # note: if no .exe extension is provided, Bun will automatically add it for Windows executables
+    ```
+
+  </Tab>
+  <Tab title="JavaScript">
+    ```ts build.ts icon="/icons/typescript.svg"
+    await Bun.build({
+      entrypoints: ["./path/to/my/app.ts"],
+      compile: {
+        target: "bun-windows-arm64",
+        outfile: "./myapp", // .exe added automatically
+      },
+    });
+    ```
+
+  </Tab>
+</Tabs>
+
 To build for macOS arm64:
 
 <Tabs>
@@ -208,7 +233,7 @@ The order of the `--target` flag does not matter, as long as they're delimited b
 | bun-linux-x64         | Linux            | x64          | ✅     | ✅       | glibc |
 | bun-linux-arm64       | Linux            | arm64        | ✅     | N/A      | glibc |
 | bun-windows-x64       | Windows          | x64          | ✅     | ✅       | -     |
-| ~~bun-windows-arm64~~ | ~~Windows~~      | ~~arm64~~    | ❌     | ❌       | -     |
+| bun-windows-arm64     | Windows          | arm64        | ✅     | N/A      | -     |
 | bun-darwin-x64        | macOS            | x64          | ✅     | ✅       | -     |
 | bun-darwin-arm64      | macOS            | arm64        | ✅     | N/A      | -     |
 | bun-linux-x64-musl    | Linux            | x64          | ✅     | ✅       | musl  |
@@ -1252,7 +1277,8 @@ type Target =
   | "bun-linux-arm64-musl"
   | "bun-windows-x64"
   | "bun-windows-x64-baseline"
-  | "bun-windows-x64-modern";
+  | "bun-windows-x64-modern"
+  | "bun-windows-arm64";
 ```
 
 ### Complete example

docs/installation.mdx

@@ -260,6 +260,13 @@ To download Bun binaries directly, visit the [releases page on GitHub](https://g
   >
     For older CPUs without AVX2
   </Card>
+  <Card
+    icon="/icons/windows.svg"
+    title="Windows ARM64"
+    href="https://github.com/oven-sh/bun/releases/latest/download/bun-windows-aarch64.zip"
+  >
+    Windows on ARM (Snapdragon, etc.)
+  </Card>
   <Card
     icon="/icons/apple.svg"
     title="macOS ARM64"

scripts/bootstrap.ps1

@@ -402,8 +402,8 @@ function Install-Bun {
   }
 
   if ($script:IsARM64) {
-    # No published ARM64 bun binary yet — download from our blob storage
-    Write-Output "Installing Bun (ARM64 from blob storage)..."
+    # ARM64 bun binary from blob storage (faster than GitHub releases for CI)
+    Write-Output "Installing Bun (ARM64)..."
     $zip = Download-File "https://buncistore.blob.core.windows.net/artifacts/bun-windows-aarch64.zip" -Name "bun-arm64.zip"
     $extractDir = "$env:TEMP\bun-arm64"
     Expand-Archive -Path $zip -DestinationPath $extractDir -Force

scripts/verify-baseline.ts

@@ -210,7 +210,13 @@ if (instructionFailures > 0) {
   console.error("    FAILED: Code uses unsupported CPU instructions.");
 
   // Report to Buildkite annotations tab
-  const platform = isWindows ? "Windows x64" : isAarch64 ? "Linux aarch64" : "Linux x64";
+  const platform = isWindows
+    ? isAarch64
+      ? "Windows aarch64"
+      : "Windows x64"
+    : isAarch64
+      ? "Linux aarch64"
+      : "Linux x64";
   const annotation = [
     `<details>`,
     `<summary>CPU instruction violation on ${platform} — ${instructionFailures} failed</summary>`,

test/cli/install/bun-upgrade.test.ts

@@ -129,6 +129,12 @@ describe.concurrent(() => {
                 "name": "bun-windows-x64-baseline.zip",
                 "browser_download_url": `https://pub-5e11e972747a44bf9aaf9394f185a982.r2.dev/releases/${tagName}/bun-windows-x64-baseline.zip`,
               },
+              {
+                "url": "foo",
+                "content_type": "application/zip",
+                "name": "bun-windows-aarch64.zip",
+                "browser_download_url": `https://pub-5e11e972747a44bf9aaf9394f185a982.r2.dev/releases/${tagName}/bun-windows-aarch64.zip`,
+              },
               {
                 "url": "foo",
                 "content_type": "application/zip",
@@ -141,6 +147,12 @@ describe.concurrent(() => {
                 "name": "bun-linux-x64-baseline.zip",
                 "browser_download_url": `https://pub-5e11e972747a44bf9aaf9394f185a982.r2.dev/releases/${tagName}/bun-linux-x64-baseline.zip`,
               },
+              {
+                "url": "foo",
+                "content_type": "application/zip",
+                "name": "bun-linux-aarch64.zip",
+                "browser_download_url": `https://pub-5e11e972747a44bf9aaf9394f185a982.r2.dev/releases/${tagName}/bun-linux-aarch64.zip`,
+              },
               {
                 "url": "foo",
                 "content_type": "application/zip",