# Dashboard design elements that slow rendering

*Tableau Consultant Study Guide · Design and Troubleshoot Calculations and Workbooks · Last updated November 3, 2026 · https://www.certifyforce.com/study-guide/tableau-consultant/design-and-troubleshoot-calculations-and-workbooks/dashboard-design-elements-that-slow-rendering*

Use the Workbook Optimizer's design guidelines to fix slow dashboards: fixed sizing, fewer visible sheets and views, summary-first drill-down, fewer layout containers and data sources, fewer filters and marks, and web images that stay within Image Role's size and count limits.

- Certification: Salesforce Tableau Consultant
- Exam section: Design and Troubleshoot Calculations and Workbooks
- Study guide: https://www.certifyforce.com/study-guide/tableau-consultant

**Official exam objective:**

> Identify and resolve performance issues caused by design elements such as number of sheets, number of filters, and image size.

## What the exam expects

- Read a Workbook Optimizer result (Take action, Needs review, Passed) and decide which design guideline to act on, ignore or autofix.
- Explain why dashboard sizing, the number of visible sheets and the number of views on a dashboard change load time, and recommend the documented fix.
- Recommend a summary-first dashboard with details on request instead of one dashboard that shows everything.
- Remove design weight that adds no value: unnecessary layout containers, unused data sources, excess filters and marks.
- Size web images for Image Role so they load: file size, images per field and the server-side rendering limit.

Key terms:
- **Workbook Optimizer:** a rules engine that checks a workbook's metadata against performance guidelines, run from the Server menu or the publishing dialog.
- **Guided drill-down:** opening with summary views and showing details only when the user asks, through action filters, show/hide containers or navigation.
- **Image Role:** a role on a discrete dimension of URLs that shows the web images in headers.
- **Server-side rendering:** Tableau Server, not the browser, draws the view, chosen when the view is complex.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Optimizer categories | Take action, Needs review, Passed (Passed and ignored once a guideline is ignored) | [Workbook Optimizer](https://help.tableau.com/current/pro/desktop/en-us/wbo_overview.htm) |
| Optimizer and publishing | Voluntary; it doesn't prevent publishing | [Workbook Optimizer](https://help.tableau.com/current/pro/desktop/en-us/wbo_overview.htm) |
| Views per dashboard | Generally two or three | [Best Practices for Effective Dashboards](https://help.tableau.com/current/pro/desktop/en-us/dashboards_best_practices.htm) |
| Sheets in a dashboard or story | Can't be deleted, only hidden | [Workbook Optimizer](https://help.tableau.com/current/pro/desktop/en-us/wbo_overview.htm) |
| Hide Card | Does not delete the filter itself | [Streamline your workbook](https://help.tableau.com/current/pro/desktop/en-us/wbo_streamline.htm) |
| Zooming | Changes the view, not the total number of marks | [Make Visualizations Faster](https://help.tableau.com/current/pro/desktop/en-us/perf_visualization.htm) |
| Image file size | Each image smaller than 200 KB | [Add Web Images Dynamically](https://help.tableau.com/current/server/en-us/image_role.htm) |
| Images per field | Usually up to 500; 100 with server-side rendering | [Add Web Images Dynamically](https://help.tableau.com/current/server/en-us/image_role.htm) |
| Render thresholds | Complexity 100 for computers, 60 for mobile, by default | [Configure Client-Side Rendering](https://help.tableau.com/current/server/en-us/browser_rendering.htm) |
| Polygon marks | Always rendered on the server | [Configure Client-Side Rendering](https://help.tableau.com/current/server/en-us/browser_rendering.htm) |

## Check yourself

- Why can a view that uses the polygon mark type still render on Tableau Server when client-side rendering is enabled?
- When would an administrator lower the mobile complexity threshold below its default of 60?
- Why can custom geocoding slow a workbook even before anyone opens a map?
- Which Optimizer category holds guidelines whose fix has minimal to no impact on the workbook's functionality?

## Sources

- [Workbook Optimizer](https://help.tableau.com/current/pro/desktop/en-us/wbo_overview.htm)
- [Streamline your workbook](https://help.tableau.com/current/pro/desktop/en-us/wbo_streamline.htm)
- [Tableau Workbook Performance Checklist](https://help.tableau.com/current/pro/desktop/en-us/perf_checklist.htm)
- [Make Visualizations Faster](https://help.tableau.com/current/pro/desktop/en-us/perf_visualization.htm)
- [Add Web Images Dynamically to Worksheets](https://help.tableau.com/current/server/en-us/image_role.htm)
- [Best Practices for Effective Dashboards](https://help.tableau.com/current/pro/desktop/en-us/dashboards_best_practices.htm)
- [Configure Client-Side Rendering](https://help.tableau.com/current/server/en-us/browser_rendering.htm)
- [Optimize Workbook Performance](https://help.tableau.com/current/pro/desktop/en-us/performance_tips.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 8 linked practice questions, and unlimited timed mock exams are included with the Tableau Consultant pack (USD $19): https://www.certifyforce.com/practice-exams