What are Tooltips in Power BI?

Hovering over a chart in Power BI and seeing a small box pop up with extra information is one of the tool's most useful features - this is a tooltip. They turn a static visual into an interactive experience, giving viewers quick access to key details without cluttering your dashboard. This article breaks down exactly what tooltips are, explains the difference between default and custom tooltips, and provides a step-by-step guide to building your own.

What Exactly is a Power BI Tooltip?

In Power BI, a tooltip is a feature that reveals additional, contextual information when a user moves their mouse over a specific data point on a visual. Think of a bar chart showing monthly sales. The chart itself gives you a high-level view of performance, but when you hover over the bar for "July," a tooltip can display the exact sales figures, the total number of orders, and perhaps the top-performing salesperson for that month.

Tooltips serve one primary purpose: to add layers of detail to your reports in an elegant and user-friendly way. Instead of trying to cram every possible metric onto a single chart, which leads to clutter and confusion, you can keep your main visuals clean and use tooltips to provide deeper insights on demand. They act as a pop-up magnifying glass, allowing users to investigate interesting data points without navigating away from the main dashboard.

The Two Main Types of Tooltips

Power BI offers two types of tooltips, each with its own level of complexity and flexibility. One is perfect for quick insights on simple visuals, while the other unlocks a whole new level of interactive reporting.

1. Default Tooltips (The Standard Option)

The simplest option is the default tooltip, which Power BI automatically generates for you. When you create a visual, Power BI looks at the data fields you’ve used and creates a simple text box that displays an exact value for the data you are hovering over.

For example, if you create a pie chart with sales broken down by product category, the default tooltip will show two things when you hover over a slice:

• The specific product category of that slice.
• The total sales amount for that category.

These tooltips are incredibly useful for quick clarifications and require zero setup. The downside is their lack of flexibility. You can't add different measures or change the formatting much beyond basic text and background colors. They only show data that is already part of the visual's configuration.

2. Custom Report Page Tooltips (The Advanced and Powerful Option)

This is where Power BI's reporting capabilities truly shine. Custom report page tooltips let you design an entirely separate, small report page that appears as your tooltip. Instead of a simple text box, you can display a combination of visuals - like cards, charts, gauges, text boxes, and even images.

Imagine your main sales dashboard has a world map visual. With a custom tooltip, hovering over a country like Germany wouldn't just show total sales. Instead, it could pop up a mini-dashboard showing:

• A card with the total sales value for Germany.
• A donut chart breaking down German sales by city.
• A small line chart showing the sales trend in Germany over the past 12 months.

The real magic is that this mini-dashboard automatically filters its data based on the data point you are hovering over. This transforms your report from a presentation tool into a genuinely interactive analytical tool, empowering users to discover insights on their own.

How to Create a Custom Report Page Tooltip (Step-by-Step)

Building a custom report page tooltip is easier than it sounds. It just involves creating a new page, designing it, and then telling a visual on your main page to use it. Here’s how you can do it in four simple steps.

Step 1: Create and Configure a New Tooltip Page

First, you need a dedicated page for your tooltip design.

1. Click the '+' icon at the bottom of the Power BI Desktop window to add a new page.
2. Right-click the new page tab and rename it to something descriptive, like "Sales Tooltip."
3. With no visuals selected, go to the Format pane (the paintbrush icon). Expand the Page information section.
4. Toggle the switch for Allow use as a tooltip to On. This crucial step tells Power BI that this page isn't a standard dashboard page but a small component you can use elsewhere.

Step 2: Set the Ideal Page Size

By default, report pages are large and not suitable for a small pop-up. You need to resize it.

1. In the same Format pane, go to the Canvas settings section.
2. Under Type, change the dropdown from "16:9" to Tooltip.

Power BI will automatically shrink the canvas to a predefined size perfect for a tooltip. This small canvas is where you'll design your custom tooltip visual. It’s also important in the same setting to select a View in the top options from Fit to Page to Actual Size in order to design the tooltip exactly as it will appear with any other zoom %.

Step 3: Add Visuals to Your Tooltip Page

Now, build your tooltip just like you would any other Power BI report, just on a smaller canvas. Drag whatever fields you want to show into the tooltip page using visualizations like:

• Cards: Perfect for displaying key numbers like total sales, profit margin, or customer count.
• Charts: A small line or bar chart can show trends over time. A pie or donut chart can break down a key metric by category.
• Tables: A simple table can list the top 5 products or customers associated with the data point.

Remember, any visual you add to this page will automatically be filtered by the data point the user is hovering over on the main visual. You don’t need to do any extra work to link them.

Step 4: Hide the Tooltip Page and Apply It to a Visual

You don't want your tooltip page to appear as a regular, clickable page for end-users, so you need to hide it.

1. Right-click the page tab of your tooltip (e.g., “Sales Tooltip”) and select Hide Page. The page will remain fully functional but will not show in the navigation.
2. Go back to your main report page and select the visual you want this new tooltip to apply to (e.g., your sales map).
3. With the visual selected, navigate to the Format your visual pane. Select General then expand the Tooltips section.
4. The Type dropdown will currently say Auto. Change the Type dropdown to Report Page and in the Page dropdown, choose the tooltip page you just created ("Sales Tooltip").

Now when you hover over a data point on your selected visual, your rich custom tooltip will appear, providing the depth of information you designed.

Practical Tips and Best Practices for Effective Tooltips

Building tooltips isn't just about technical skills - it's also about good design practices. Here are a few tips to keep in mind:

• Keep It Clean and Concise: Tooltips should be short and to-the-point - it's a balance between giving enough detail without overwhelming.
• Ensure Readability: Tooltips are smaller in size, so choose colors and fonts that are easy to read against your background to avoid eye strain.
• Keep Context Relevant: Ensure the visuals in your tooltip relate directly to the data the user is hovering over. For example, if your chart shows sales by product, your tooltip should show details on those products, not a random metric like staff satisfaction.
• Test Performance: Make sure tooltips load quickly and do not impair performance, slow tooltips can disrupt the user experience.

Final Thoughts

Tooltips are an exceptional resource in reporting - carefully designed tooltips are a powerful way to transform Power BI dashboards from static charts into dynamic and engaging explorations. They allow users to drill down to details on their own and connect with information that enhances the data storytelling experience.

Using tooltips in Power BI is a great way to offer interactive insights on your dashboards by transforming them from static visuals to layers of context without cluttering your main visuals. That power allows your audience to drill down to details of their own interest, experiencing the report in a more informed and comprehensive manner.

To bridge the gap between basic questions and creating effective solutions, it is important to remain mindful of how the tooltips enhance comprehension. This article is a starting point, offering guidance for creating impactful tooltips that communicate effectively with your audience.

I use Graphed to help keep track of tooltips and analyze their data’s performance, making decisions based on what enhances user comprehension and engagement most effectively.