# Profile a Web build

> Record performance data for Web builds using the Unity Profiler.

Record performance data for Web builds using the Unity Profiler.

To connect a Web build to the [Unity Profiler](/engine/6000.3/manual/analysis/profiler.md), you can use the temporary local server created during the **Build and Run** process or manually connect to a device using its IP address. Both methods require a **Profile** button in the application. This button is included in the Default and PWA [Web templates](/engine/6000.3/manual/platform-specific/webgl/building-distribution/templates.md), but you must add it to all other templates.

**Notes:**

* Profiling is only available for development builds.
* Unity can profile basic draw call data for Web applications, but the [Frame Debugger](/engine/6000.3/manual/analysis/graphics-performance-profiling/profiling/frame-debugger-window.md) doesn't work on the Web platform.

To profile on a different platform, refer to [Collect performance data on a target platform](/engine/6000.3/manual/analysis/profiler/profiling-applications/profiling-target-device.md).

## Profile on a temporary local server (automatic connection)

> **Note:**
>
> The Default and PWA [Web templates](/engine/6000.3/manual/platform-specific/webgl/building-distribution/templates/web-templates-intro.md) include a **Profile** button by default. For all other templates, you must [Add the Profile button to your template](#add-profiler-button) before following these steps.

To profile your Web build on a Unity temporary local server:

1. Open the **Build Profiles** window (menu: **File** > **Build Profiles**).
2. Select **Web** as the target platform.
3. Enable Development Build.
4. Enable **Autoconnect Profiler**.
5. Select **Build and Run**. Unity starts a temporary local server and opens the build in your browser. The build automatically connects to the Profiler and starts profiling.
6. To disconnect, in the running build, select **Stop Profiling**.
7. View real-time performance data in the **Profiler** window.

> **Tip:**
>
> To collect profiling data when the browser window is inactive, in Player Settings (menu: **Edit** > Editor > **Player**), enable **Run In Background**.

## Profile on another device or server (manual connection)

> **Note:**
>
> The Default and PWA [Web templates](/engine/6000.3/manual/platform-specific/webgl/building-distribution/templates/web-templates-intro.md) include a **Profile** button by default. For all other templates, you must [Add the Profile button to your template](#add-profiler-button) before following these steps.

To profile your Web build on a custom server or another device:

### Prepare your build

1. Open the **Build Profiles** window (menu: **File** > **Build Profiles**).
2. Select **Web** as the target platform.
3. Enable **Development Build**.
4. Select **Build** or build your project with scripting.

### Connect to the Profiler and collect data

1. Open the Profiler window (menu: **Window** > **Analysis** > **Profiler**).

2. Select **Play Mode** > **Enable Web Profiling**.


   **The Enable Web Profiling option in the Profiler window.:**
   ![](/api/media?file=/engine/6000.3/media/images/web-profiling-window.png)

3. A window opens showing that web profiling is active. Copy the IP address and port from the window.

4. Run your build. In the running build, select **Profile**.


   **The Profile button in a Web build.:**
   ![](/api/media?file=/engine/6000.3/media/images/web-profiling-start.png)

5. A window opens requesting the connection information. Paste in the IP address and port.

6. To disconnect, in the running build, select **Stop Profiling**.

7. View real-time performance data in the **Profiler** window.

### Collect startup data on another device or server

If your build is running on the same device as the Unity Editor, you can enable the **Autoconnect Profiler** option in the Build Profiles window to collect startup data automatically. To use **Autoconnect Profiler** on another device, you must manually add the IP address in the player arguments of your build.

To configure another device to use **Autoconnect Profiler**:

1. Open the `index.html` file of your build.

2. Find the following line:

   ```html
   var config = {
   arguments: []
   // ...
   }
   ```

3. Modify it to include the IP address and port you copied from the Profiler window, where `xxxxxx` is the IP address and port:

   ```html
   var config = {
   arguments: ["--player-connection-ip=xxxxxx"],
   // ...
   }
   ```

4. Save the `index.html` file and run your build.

## Add the Profile button to a custom Web template

To add the **Profile** button to a [custom Web template](/engine/6000.3/manual/platform-specific/webgl/building-distribution/templates/web-templates-add.md):

1. In your custom template's `index.html` file, add the following near the top of the file:

   ```html
   #if DEVELOPMENT_PLAYER
     <script src="<<<TemplateData/profiler.js>>>"></script>
   #endif
   ```

2. In the script section where you create the Unity instance, add the following code after the instance is available:

   ```js
    #if DEVELOPMENT_PLAYER
     var profile = unityProfiler.createButton(unityInstance);
     profile.style.position = 'fixed';
     profile.style.bottom = '5px';
     profile.style.left = '5px';
     // Adds the Profile button to the body element of the page.
     // You can change this line to append the button to a different element as needed.
     document.body.appendChild(profile); 
   #endif
   ```

3. (Recommended) When handling player quit or unload, add the following to remove the **Profile** button and clean up resources:

   ```js
   unityProfiler.shutDown();
   ```

After making these updates, follow the steps to [Profile on a temporary local server](#profile-temp-server) or [Profile on another device or server](#profile-another-device).

## Additional resources

* [Optimize your Web build](/engine/6000.3/manual/platform-specific/webgl/building-distribution/web-optimization.md)
* [Optimize Web platform for mobile](/engine/6000.3/manual/platform-specific/webgl/building-distribution/web-optimization-mobile.md)
* [Unity Profiler](/engine/6000.3/manual/analysis/profiler.md)