# Adding profiling information to your code introduction > Use profiler markers and counters to collect specific data about your application. By default, the [Profiler window](/engine/6000.6/manual/analysis/profiler/window.md) displays information about Unity’s native code. It uses [built-in profiler markers](/engine/6000.6/manual/analysis/profiler/markers.md) to organize and divide up the performance data it collects. You can add profiler markers to your own code to make timings spent in these areas visible in the Profiler window with the [`ProfilerMarker` API](/engine/6000.6/script-reference/unity/profiling/profilermarker.md). You can also add Profiler counters to your code to collect data for metrics in your application, and use [custom profiler modules](/engine/6000.6/manual/analysis/profiler/customizing/creating-custom-modules.md) to display this data. This is useful if you want to track performance changes in your application. Adding profiler counters to your code speeds up the investigation of performance issues because you can use the information from your counters in conjunction with Unity’s built-in counters and instrumentation data. To add counters and markers with metadata to your code, you need to use the [Unity Profiling Core](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest?subfolder=/manual/index.html) package. > **Important:** > > The Unity Profiling Core package isn't discoverable in the Package Manager UI because it's a core package. To install the package, [add it by name](/engine/6000.6/manual/packages-list/managing-packages-window/upm-ui-actions/upm-ui-quick.md), which is `com.unity.profiling.core`. ## Profiler markers You can use the [`ProfilerMarker` API](/engine/6000.6/script-reference/unity/profiling/profilermarker.md) to mark up resource-intensive script code blocks and make them visible in the Unity Profiler, or use the [`ProfilerMarker` API](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerMarker-1.html) in the [Unity Profiling Core](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest) package to add extra metadata to each sample it produces. This can be useful because the built-in Unity Profiler doesn’t profile all method calls. The alternative is to [use deep profiling,](/engine/6000.6/manual/analysis/profiler/deep-profiling.md) but this causes a large overhead that significantly slows down your application execution and skews the results. Using `ProfilerMarker` is a more efficient way of marking up your code. `ProfilerMarker` represents a named Profiler handle and is the most efficient way of profiling your code. You can use it in any of your application's C# code. Profiler markers have no overhead when Unity deploys them in a non-development build, so you can mark up as many samples as you like. Unity marks `Begin` and `End` methods with [`ConditionalAttribute`](https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.conditionalattribute?view=net-8.0) and conditionally compiles them, so they have zero execution overhead in non-development builds. While `Auto` methods are not entirely compiled out in non-development builds, they are conditionally compiled to just return null, making their overhead negligible. The profiler marker’s field is present in release builds and takes up memory equivalent to its [`IntPtr`](https://learn.microsoft.com/en-us/dotnet/api/system.intptr?view=net-8.0), which is 8 bytes. The [`ProfilerRecorder`](/engine/6000.6/script-reference/unity/profiling/profilerrecorder.md) API also uses profiler markers to capture performance data. During development in the Unity Editor and in Development Players, you can use the API to get a performance overview of the different parts of your code and to identify performance issues. ## Profiler counters To display custom metrics in the Unity profiler, use the `ProfilerCounter` API in the [Unity Profiling Core](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest?subfolder=/manual/index.html) package. The Profiler can display data from [`ProfilerCounter`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerCounter-1.html) or [`ProfilerCounterValue`](https://docs.unity3d.com/Packages/com.unity.profiling.core@1.0/api/Unity.Profiling.ProfilerCounterValue-1.html). Unity groups Profiler counters into categories based on the type of work the counters profile, for example, Rendering, Scripting, or Animation. You can assign a custom Profiler counter to any of Unity's profiling categories. For a full list of available Profiler categories, refer to [`ProfilerCategory`](/engine/6000.6/script-reference/unity/profiling/profilercategory.md). You can use the `ProfilerCounter` or `ProfilerCounterValue` API to track metrics of your application and make them visible in the Unity Profiler or in other code. If you’re an Asset Store package developer, you can add Profiler counters to your code to help other developers understand important performance characteristics of your system, and they can use this information for optimization or budgeting tooling. The following diagram displays a high level overview of the Profiler counters data flow: **Profiler counters flow.:** ![](/api/media?file=/engine/6000.6/media/images/profiler-counter-diagram.png) The [`ProfilerRecorder`](/engine/6000.6/script-reference/unity/profiling/profilerrecorder.md) API retrieves Profiler counter data in your application code, and the [`RawFrameDataView`](/engine/6000.6/script-reference/unityeditor/profiling/rawframedataview.md) or [`HierarchyFrameDataView`](/engine/6000.6/script-reference/unityeditor/profiling/hierarchyframedataview.md) APIs get the Profiler counter data in the Editor code. You can visualize this counter data in the Profiler window by [configuring a custom Profiler module in the Module Editor](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/creating-custom-counters.md). `ProfilerCounter` and `ProfilerCounterValue` support the following types: * int * long * float * double ## Additional resources * [Adding profiler markers to your code](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/add-markers-code.md) * [Adding profiler counters to your code](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/add-counters-code.md) * [Visualizing profiler counters](/engine/6000.6/manual/analysis/profiler/customizing/adding-information-code/creating-custom-counters.md) * [`ProfilerMarker` API](/engine/6000.6/script-reference/unity/profiling/profilermarker.md) * [Profiling Core package](https://docs.unity3d.com/Packages/com.unity.profiling.core@latest)