Canva provides a built-in highlight effect through its Effects panel, under the label Background. When applied, it places a colored rectangular slab behind the selected text. Both free and Pro accounts include this feature.
To apply it, select your text box and click Effects in the top toolbar. Inside the panel, locate and click Background. The treatment hits the entire text box instantly. A color picker appears so you can swap the shade. Two sliders control corner rounding and how sheer the foreground element feels.
The main constraint: this effect cannot target a single word. It always covers the full box. To highlight only a few words, you must chop your text into separate boxes. Place the words you want emphasized into their own box, apply the Background treatment to that box alone, and position it over the remaining copy. That is the sole path to selective emphasis inside Canva.
How to adjust highlight appearance
Color and defaults
After applying the Background effect, the color picker lets you pull any shade from Canva's palette or enter a hex code. The default tint is usually a semi-sheer yellow, but you can match brand or design colors immediately.
Corner rounding and opacity
The roundness slider curbs the block's edge radius. At zero you get sharp edges; as you raise the value, the shape melts into a pill-like form. The transparency slider governs how much of the layer behind seeps through. At full opacity the color bar is solid; at lower levels it becomes a translucent wash.
These controls work independently. You can combine a fully opaque slab with pillowed edges, or a faint rectangle with crisp angles. The sweet spot depends on the typeface, the background image or color underneath, and how far away someone will read the finished piece. For body copy sitting on a busy scene, roundness around 30 percent and transparency around 20 percent yields a legible but quiet emphasis. For headings or callouts, higher opacity and cleaner edges create heft.
No keyboard shortcut
Canva does not offer a shortcut for this effect. You cannot press, say, Ctrl H to fire it. The Effects panel is the only route.
Manual highlight using shapes
Building a highlight from Elements
If the Background effect does not suit your needs, you can construct a highlight manually with Canva's Elements tool. This route gives you finer control over placement and shape, though it adds steps.
Open Elements from the left sidebar. Under Shapes, pick the rectangular block and drag it onto the canvas. Stretch it so it sits behind the text you want to surface. Use the color picker in the top toolbar to fill the shape with your chosen tone. Adjust its sheerness with the slider that appears when you click the element. To soften the edges, drag the corner rounding handle that materializes when you hover near any corner of a selected shape.
Targeting single words
The manual approach sidesteps the Background effect's biggest constraint: you can tuck a shape behind a single word or phrase while leaving the rest untouched. For each word you want to flag, create a separate block, size and place it individually, then right-click and choose Send backward or Send to back.
The cost is speed. Every highlight demands several moves. In a document with many flagged passages, the built-in Background effect wins on pace, even though it highlights whole text boxes only.
Highlighting words in a single text box
Why word-level highlighting fails
Canva does not support highlighting individual words inside a single text box. This confuses users arriving from word processors like Microsoft Word or Google Docs, where selecting a word and clicking highlight is trivial. In Canva, text is a single object inside its container. Every background modification, including the Background effect, acts on the whole box at once.
The workaround
You must break your copy into multiple boxes. Keep unhighlighted words in one box and place each term or phrase you want emphasized into its own separate box. Arrange the highlighted boxes so they read in the correct order. Apply the effect only to those. Canva's alignment guides, pink lines that flash during drags, help keep boxes lined up horizontally and vertically.
The trade-off
A paragraph with three emphasized words demands at least four text boxes: one for the base copy and one for each term. This bloats complexity if you later adjust the text. Shifting a word's spelling or size might force you to reposition several boxes. That is why many Canva users reserve the Background treatment for short bursts: a single sentence, a heading, not sprawling paragraphs dotted with scattered pops.
When the highlight effect matters
A design tool, not a markup tool
The highlight effect in Canva serves visual emphasis. It sharpens a callout on a social graphic, brands a quote with a colored slab, or helps a label stand against a photo. It does not suit annotating a document for review or marking up a report. Its intent is design polish, not collaborative notation.
For personal reading marks
If you need to highlight passages inside a Canva document for your own reading, such as flagging key facts in an infographic you are reviewing, use the manual shape method described earlier. That approach produces marks that look identical to the built-in effect while sitting anywhere, at any size, over any portion of text. You can delete the rectangles later without touching the text.
Limits and workarounds
Canva positions highlighting as a basic design feature. It skips advanced options: gradient slabs, patterned fills, or animations attached. If you need those, export the design to another tool such as Adobe Express or a dedicated video editor and layer them there. For the vast majority of static design jobs inside Canva, the Background effect and the manual rectangle technique cover every practical scenario. Neither is difficult. The choice hinges on whether you need to emphasize entire text boxes or isolated words inside one.
