Visual Aids and Graphics
In technical documentation, visual aids are not optional extras; they are part of the core content.
When a reader encounters a complex step, a well-placed screenshot or diagram can confirm their progress, clarify ambiguous text, and reduce cognitive load. This is especially true for UI-heavy applications and complex system architectures.
The Three Rules of Technical Graphics
Before adding any image, ask yourself: Does this visual aid make the next step easier to understand? If the answer is no, the image is distracting.
1. Focus and Crop
Never use a full-desktop screenshot. Crop tightly to show *only* the relevant element (button, field, dialog box). The user should see immediately what they need to click.
2. Annotate Clearly
Use boxes, arrows, and circles to highlight the exact target. Never rely on just cropping; visually guide the user's eye with consistent colors.
3. Maintain Consistency
Use the same aspect ratio, padding, color palette, and arrow style across all your documentation. Graphics should look like they belong to the same professional guide.
Accessibility and Text Alternatives
Remember that images are invisible to screen readers and search engines. You must provide descriptive text for every image.
- Alt Text (Required): A concise, descriptive sentence that conveys the purpose of the image. (e.g.,
alt="Screenshot of the Settings menu with the 'Advanced' tab selected.") - Captions (Recommended): Use captions for complex diagrams or figures that need a brief explanation directly beneath them.
If your documentation supports a dark theme (like this site), ensure your screenshots are either theme-agnostic (using a neutral background color) or include separate versions optimized for light and dark modes to prevent a jarring visual experience.
When to Use Specific Visual Types
The type of visual you choose should align with the content structure (which we learned about in the previous section).
| Visual Type | Best Used In | Purpose | Tooling Examples |
|---|---|---|---|
| Screenshot | How-To Guides, Tutorials | To show the result of a step or the next target in a UI. | Snagit, ShareX, native OS tools. |
| Flowchart/Diagram | Explanations, Tutorials | To illustrate system architecture, data flow, or a decision tree. | Mermaid.js, PlantUML, Miro, Lucidchart. |
| Code Snippets | Reference, How-To Guides | While not a traditional "graphic," well-formatted code is a visual aid. | Code blocks with syntax highlighting. |
| GIF / Short Video | How-To Guides, Tutorials | For complex sequences of steps (e.g., drag-and-drop actions, filling out a form). | Loom, ScreenToGif. |
Diagramming with Code
For technical documentation, relying on image files for diagrams has a major drawback: they are hard to update.
A modern, developer-centric alternative is using a diagramming language like Mermaid.js (which Docusaurus can easily support via a plugin). This allows you to define a flowchart or sequence diagram using simple markup, which then renders into a scalable, theme-aware SVG.
This approach treats your diagrams like code: they are versionable, easy to review, and maintain consistency automatically.