How to Create a Realistic Highlight Effect in After Effects (Step-by-Step)

Highlighting text is one of the most effective ways to direct your viewer's attention in educational videos, presentations, or social media content. You see this effect everywhere, from Vox documentaries to high-end YouTube tutorials, because it works. The good news is, you don't need third-party plugins to achieve this look. With just the built-in tools in After Effects, you can create a professional, animated highlighter effect in under two minutes.

Here is your guide to creating that perfect, satisfying marker stroke.

Setting Up the Foundation

First, you need to draw the stroke that will act as your highlighter ink.

1. Deselect All Layers: Click on an empty space in your timeline. If you have your text layer selected, the Pen Tool will create a mask instead of a shape layer. We want a Shape Layer.
2. Select the Pen Tool: You can click the icon in the toolbar or simply press G on your keyboard.
3. Draw Your Line: Click once at the start of the word you want to highlight, and click again at the end. Hold Shift while clicking to ensure the line is perfectly straight.

Once the line is drawn, head over to the properties panel. You don't need a Fill color, so turn that off. Focus on the Stroke. For a classic highlighter look, a bright neon yellow (Hex: #FFFF00) is the standard choice, but cyan, bright green, or pink work great for different vibes.

Increase the Stroke Width until the line covers the height of your text. A value between 40px and 60px usually works well depending on your font size.

Pro Tip: In the Shape Layer properties, find Stroke settings and change the Line Cap to Round Cap. This gives the ends of your stroke a rounded, more natural marker-tip appearance rather than a harsh digital rectangle.

The Secret to Realism: Blending Modes

Right now, your line probably looks like a solid block of color sitting on top of your text, obscuring it. To make it look like real ink on paper, we need to change how it interacts with the layers beneath it.

Select your Shape Layer (the highlight) and find the Mode column in your timeline. Change the Blending Mode from Normal to Multiply.

Multiply is the magic switch here. It makes the yellow transparent only to the darker pixels underneath, allowing the black text to pop through the color clearly, just like a real highlighter marker.

Animating the Stroke

Now that the style is set, let's make it move. We will use Trim Paths to animate the line drawing itself on the screen.

1. Open your Shape Layer properties and click the Add button (the small arrow icon next to Contents).
2. Select Trim Paths from the menu.
3. Expand the Trim Paths settings. You will see Start and End values.
4. Move your playhead to the beginning of the animation (e.g., 0:00).
5. Click the stopwatch icon next to End and set the value to 0%.
6. Move forward in the timeline (e.g., to 1:00 or 15 frames) and set the End value to 100%.

Press Space to preview. You now have a basic animation where the line draws itself over the text.

If you are working on complex projects with multiple text elements, mastering tools like auto-resizing text boxes in After Effects can save you even more time alongside this technique.

Polishing the Movement

A linear animation can feel a bit robotic. Real hand movements start slow, speed up, and slow down again. To achieve this organic feel:

1. Select both keyframes you just created for the End property.
2. Press F9 on your keyboard. This applies Easy Ease, smoothing out the velocity of the animation.
3. For extra control, open the Graph Editor. Pull the handles to create a bell curve (peaking in the middle). This makes the stroke draw quickly in the middle and settle gently at the end, mimicking a confident hand swipe.

Scaling Up for Multiple Words

You don't need to redraw the path for every single word you want to highlight. Workflow efficiency is key in motion graphics.

Simply select your finished highlighter layer and press Ctrl + D (Command + D on Mac) to duplicate it. Move the new layer to the next word in the timeline. If the new word is shorter or longer, you don't need to redraw. Just press G again to activate the Pen Tool, select the path points, and drag them to fit the new text length. The animation and style settings will remain perfectly intact.

This technique pairs perfectly with other dynamic effects. For instance, if you are creating a dashboard or data visualization video, combining this with a dynamic timer in After Effects creates a cohesive and engaging visual style.

By following these steps, you have added a versatile tool to your motion graphics arsenal that adds instant production value to any text-based content.