---
title: "Parca template variables | Grafana Cloud documentation"
description: "Use template variables with the Parca data source in Grafana."
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# Parca template variables

Instead of hard-coding label values in your profiling queries, you can use template variables to create dynamic, reusable dashboards. Variables appear as drop-down menus at the top of the dashboard, making it easy to switch between services, instances, or environments without editing queries.

For an introduction to template variables, refer to the [Variables](/docs/grafana/next/dashboards/variables/) documentation.

## Supported variable types

Expand table

| Variable type | Supported | Notes                                                                        |
|---------------|-----------|------------------------------------------------------------------------------|
| Custom        | Yes       | Define a static list of values manually.                                     |
| Text box      | Yes       | Enter a free-form value at the top of the dashboard.                         |
| Constant      | Yes       | Define a hidden, fixed value.                                                |
| Data source   | Yes       | Select a data source instance by name.                                       |
| Query         | No        | Parca doesn’t implement variable queries to dynamically populate drop-downs. |

> Note
> 
> Parca doesn’t support query-type variables. You can’t use the Parca data source to dynamically populate variable drop-downs. Use custom variables to define values manually, or use another data source to populate query variables.

## Use variables in the label selector

The Parca query editor’s label selector field supports template variable interpolation. Use the standard `$variablename` or `${variablename}` syntax. Variables are interpolated in the label selector only – the profile type drop-down doesn’t support them.

### Variable syntax options

Expand table

| Syntax                   | Description                                                                      |
|--------------------------|----------------------------------------------------------------------------------|
| `$variablename`          | Simple syntax for most cases.                                                    |
| `${variablename}`        | Use when the variable is adjacent to other text (for example, `${host}_suffix`). |
| `${variablename:format}` | Apply a specific format to the variable value.                                   |

## Example: Filter profiles by service

Create a custom variable to switch between services in your profiling dashboard.

01. Navigate to the dashboard you want to update and click **Edit**.
02. Click the **Add new element** icon (blue plus sign).
03. Click **Variable**.
04. Select **Custom** as the variable type.
05. Enter a **Name**, for example `service`.
06. Select an option in the **Display** drop-down list to control where on the dashboard the variable is displayed.
07. Click **Open variable editor** to open the **Custom options** dialog box.
08. Enter comma-separated values, for example `frontend, backend, api-gateway`.
09. Click **Apply**.
10. Click **Save**.
11. (Optional) Enter a description of the changes you’ve made.
12. Click **Save**.
13. Click **Exit edit**.

In your Parca query’s label selector, reference the variable:

text ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```text
{job="$service"}
```

When you change the drop-down selection, the panel refreshes to show profiles for the selected service.

## Example: Filter by service and instance

Create two custom variables to filter by multiple dimensions.

1. Create a variable named `service` with custom values `frontend, backend, api-gateway`.
2. Create a second variable named `instance` with custom values for your instance addresses, for example `10.0.0.1:7070, 10.0.0.2:7070, 10.0.0.3:7070`.

In your Parca query’s label selector, reference both variables:

text ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```text
{job="$service", instance="$instance"}
```

## Example: Use a text box variable for free-form filtering

Create a text box variable for free-form label filtering.

01. Navigate to the dashboard you want to update and click **Edit**.
02. Click the **Add new element** icon (blue plus sign).
03. Click **Variable**.
04. Select **Textbox** as the variable type.
05. Enter a **Name**, for example `label_filter`.
06. Optionally set a default **Value**, for example `job="my-service"`.
07. Click **Save**.
08. (Optional) Enter a description of the changes you’ve made.
09. Click **Save**.
10. Click **Exit edit**.

In your Parca query’s label selector, reference the variable:

text ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```text
{$label_filter}
```

This lets you type any label matcher directly into the variable input at the top of the dashboard without editing the panel query.

## Limitations

Parca template variable support has the following limitations:

- **No query variable support:** You can’t use Parca as a data source for populating variable options. Define values manually with custom variables or use another data source.
- **Label selector only:** Variables are interpolated in the label selector field. The profile type drop-down doesn’t support variables.
- **No free-form filters:** Parca doesn’t support free-form [filters](/docs/grafana-cloud/learn-and-build/visualizations/dashboards/build-dashboards/filter-group-by/).

## Next steps

- [Build queries](/docs/grafana-cloud/observe-and-act/connect-externally-hosted/data-sources/parca/query-editor/) using your template variables.
- [Troubleshoot issues](/docs/grafana-cloud/observe-and-act/connect-externally-hosted/data-sources/parca/troubleshooting/) if queries aren’t returning expected data.