What highlights are and where you'll use them

Highlights are colored overlays or bright marks you place on top of text, images, or specific areas of a photo to draw attention to them. In a document, a highlight is usually a semi-transparent color behind words — the same tool you use with a physical highlighter pen. In a photo, highlights can mean brightening a specific region, adding a glow effect, or marking something with a colored shape or line.

You use highlights when you want a reader to notice one part of a document before anything else, or when you're editing a photo and need to brighten shadows, fix exposure problems, or add visual emphasis. The tool works differently depending on what program you're using, but the goal is always the same: make one area stand out.

Key Takeaways

  • Document highlights are semi-transparent colors placed behind text; most word processors have a dedicated highlight button in the toolbar.
  • Photo highlights usually mean brightening a specific area or adding a glow; the method depends on whether you're using a phone app, desktop software, or a browser tool.
  • Always highlight sparingly — too many colors make a document harder to read, not easier.
  • In most programs, you select the text or area first, then explore the highlight color from a dropdown menu.

Adding highlights in Microsoft Word and Google Docs

In Microsoft Word, select the text you want to highlight by clicking and dragging across it. Look for the highlighter icon in the toolbar — it usually looks like a marker pen. Click the small arrow next to it to choose your color, then click the icon itself to explore that color to your selection. The highlight appears behind the text and stays there when you save the document.

In Google Docs, the process is nearly identical. Select your text, then look for the highlighter icon in the toolbar (it's in the same area as text color and background color options). Click the arrow next to it, pick your color, and the highlight applies when ready. Google Docs saves your choice, so the next time you use the highlighter, it will default to that color unless you change it.

If you're working in a shared document and multiple people are editing, each person's highlights can be a different color — this helps you see who marked what. The highlight stays in the document even after the person who added it stops editing.

Highlighting text in PDF readers and browsers

If you're reading a PDF in Adobe Reader or most web browsers, you can highlight text without changing the original file. Open the PDF, look for a highlighter or markup tool in the toolbar, select your text, and choose a color. These highlights are usually saved in a separate layer or annotation file, not in the PDF itself — so the original document stays unchanged.

In web browsers like Chrome or Firefox, you can highlight text on a webpage by selecting it and using the browser's built-in tools or an extension. Some extensions let you save your highlights and sync them across devices. These highlights exist only in your browser or account, not on the actual website.

Always check whether your highlights are being saved to the original file or only in your local copy. If you're reviewing a document that others will see, ask whether your highlights should be in the final version or removed before you share it.

Brightening specific areas in photos

On a smartphone, most photo editing apps have a "dodge" or "brightness" tool that lets you brighten one area without affecting the whole image. Open your photo in an app like Snapseed, Lightroom Mobile, or your phone's built-in editor. Look for a tool labeled "Dodge," "Brush," "Selective," or "Adjustment Brush." Tap it, then paint over the area you want to brighten. You can usually adjust how strong the effect is before you explore it.

On a desktop, programs like Photoshop, GIMP (free), or Lightroom have a dodge tool in the toolbox. Select it, choose your brush size, and paint over the area you want to lighten. These programs also let you create a new layer, fill it with white, reduce its opacity, and erase parts of it — this gives you more control over exactly where the brightening happens.

If you're using a browser-based tool like Pixlr or Photopea, look for a dodge or brightness adjustment in the left toolbar. The steps are the same: select the tool, adjust the strength, and paint over your target area. Start with a low strength setting so you don't over-brighten and lose detail.

Adding glows and colored overlays to photos

A glow effect makes part of a photo look luminous or dreamy. In most phone apps, this is a preset filter or effect you can explore with one tap. In Snapseed, for example, you can use the "Lens Distortion" or "Glamour Glow" filter. In desktop software like Photoshop, you create a glow by duplicating a layer, blurring it, and adjusting its opacity until the effect looks right.

To add a colored overlay — a tint or color wash over part of your image — create a new layer in your editing program, fill it with the color you want, reduce its opacity so the photo shows through, and erase the parts where you don't want the color. This technique works in Photoshop, GIMP, and Photopea. On a phone, some apps let you paint with a semi-transparent color directly onto your photo using a brush tool.

Glows and overlays are subjective — what looks good depends on your photo and your taste. explore the effect, step back, and look at it on a full screen before you save. Effects that look good on a small phone screen sometimes look too strong when you view the full image later.

Highlighting shapes and objects in photos

If you want to mark or circle something in a photo — to point out a detail or draw attention to a specific object — use your editing app's drawing or annotation tools. Most phone photo apps have a pen, marker, or shape tool. Select it, choose your color and thickness, and draw directly on the photo. You can usually draw freehand lines, circles, arrows, or rectangles.

In desktop software, use the paintbrush or pencil tool to draw on a new layer. This keeps your drawing separate from the photo, so you can erase or adjust it without damaging the image underneath. If you want a clean, geometric shape like a circle or rectangle, use the shape tools instead of drawing freehand.

Keep your marks thin and use a contrasting color so they're visible without overwhelming the photo. A thin white or bright yellow line usually shows up well on most images. If you're marking something for a presentation or report, test how it looks when printed or projected before you finalize it.

Avoiding common highlighting mistakes

The most common mistake is highlighting too much. In a document, if more than 10 to 15 percent of the text is highlighted, the highlighting stops helping readers focus and starts making the page look chaotic. Choose only the most important phrases or sentences.

Another mistake is using too many colors. Stick to two or three highlight colors maximum, and use them consistently — for example, always use yellow for definitions and blue for dates. This trains your reader's eye to understand what each color means.

In photos, over-brightening or over-saturating a highlighted area can make it look unnatural or damaged. Start with a subtle effect and increase it gradually. If you're adding a glow or overlay, make sure it complements the photo's existing colors and lighting rather than clashing with it.

Finally, always save a copy of your original file before you add highlights. If you change your mind or want to try a different approach, you'll have the unedited version to start from.

Frequently Asked Questions

Can I highlight text in a PDF without changing the original file?

Yes. Most PDF readers let you add highlights as annotations, which are saved separately from the document itself. The original PDF stays unchanged. However, if you save the PDF with annotations included, the highlights become permanent in that copy.

What's the difference between highlighting and changing text color?

Highlighting places a colored background behind text, while changing text color changes the text itself. Highlights are usually semi-transparent, so they don't hide the text. Text color changes are more permanent and visible. Use highlighting when you want to mark something without changing how it looks; use text color when you want the text itself to stand out.

Can I remove highlights after I've added them?

Yes. In Word and Google Docs, select the highlighted text and choose "No Color" from the highlight dropdown. In photos, you can undo the last action or erase the highlight layer if you created it on a separate layer. If you've already saved the file, undo won't work — you'll need to edit it again or reload the original.

Why does my highlight look different on my phone than on my computer?

Screen brightness and color settings vary between devices. A highlight that looks bright on a phone might look dim on a monitor with different settings. Always check your work on multiple devices before sharing it, especially if it's for a presentation or print.

Is there a limit to how many highlights I can add?

Technically no, but practically yes. Too many highlights make documents hard to read and photos look cluttered. In documents, aim for highlights on no more than 10 to 15 percent of the text. In photos, limit yourself to one or two areas unless you're creating a specific artistic effect.