How to Round Corners in DaVinci Resolve

To round a video in DaVinci Resolve, open the clip in Fusion, select MediaIn1, and add a Rectangle mask. Confirm Rectangle1 feeds MediaIn1’s blue mask input, then select Rectangle1 and increase Corner Radius. Keep Soft Edge near zero for a clean card; place a background on the track below when the transparent outside area shouldn't appear black.

The click sequence is short. The part that catches editors is everything around it: the mask can land on the wrong node, non-uniform scaling can stretch the curves, and a perfectly good transparent result can look black when there's nothing underneath it. This guide covers the dependable Fusion setup first, then the faster alternatives for graphics and multi-clip sequences.

Choose the Method That Matches the Job

The standard Fusion method works in DaVinci Resolve Free. The final DaVinci Resolve 21 Reference Manual documents Rectangle masks, the blue effects-mask input, Width, Height, Soft Edge, and Corner Radius. No plug-in or baked PNG frame is required.

Round a Video with a Fusion Rectangle Mask

1. On the Edit page, place the clip on V2. Put the background video, color or graphic on V1.
2. Select the V2 clip and open the Fusion page.
3. Confirm that MediaIn1 is connected to MediaOut1.
4. Select MediaIn1, then click the Rectangle mask button in the Fusion toolbar. Resolve should create Rectangle1 and connect it to the blue mask input on MediaIn1.
5. Select Rectangle1. Set Width and Height so the mask sits slightly inside the frame.
6. Increase Corner Radius until the curve suits the card.
7. Leave Soft Edge at zero or very low for crisp UI-style corners. Add feather only when the composite genuinely needs a softer edge.
8. Return to the Edit page and watch the entire clip over its final background.

The checkerboard in the Fusion Viewer means transparency; it isn't a fault. On the Edit page, that area reveals the lower track. If there's no lower track, the timeline background is normally black, so the finished frame looks as though the mask added a black border.

If the Rectangle Does Nothing, Check the Connection

A Fusion node has different input types. The yellow connection carries an image. The blue input limits that image or effect with a mask. Rectangle1 must feed the blue input on the node you want to cut.

If you drop a Rectangle into empty space, Resolve creates the tool without necessarily connecting it where you intended. Drag Rectangle1’s output square to MediaIn1’s blue triangle, or delete the loose node, select MediaIn1 and add Rectangle again. The latter is usually faster and avoids connecting the mask to MediaOut or an unrelated effect.

If the node graph still feels opaque, the site’s Fusion tutorial for beginners explains viewers, image connections, masks and Merge nodes before you build a larger composite. Blackmagic also provides current Resolve training books and lesson files with downloadable practice projects.

Resize the Card Without Stretching Its Corners

Rectangle1 defines the visible shape. A Transform node changes the position and scale of the image. Those jobs look interchangeable until X and Y are scaled by different amounts.

If you create the rounded mask and then stretch the finished result vertically or horizontally, the curve stretches with it. A circular corner becomes an oval. Apply the aspect-ratio-changing transform before the Rectangle mask, or calculate the mask after the image reaches its final proportions. When the entire timeline needs a new shape rather than one picture-in-picture card, use the separate aspect-ratio workflow for Resolve before building the mask.

Blackmagic lays out Corner Radius as a normalized 0.0–1.0 control but doesn't publish a fixed-pixel formula. In practice, editors report that the same value can look different after Width or Height changes; this recurring Fusion Rectangle discussion is directional workflow evidence, not an official algorithm definition. Set the radius by eye at the final size, or use Shape tools or an expression when dimensions animate.

Use One Rounded Frame Across Multiple Clips

Copying the same Fusion composition to ten edits works until one clip is trimmed, reframed or replaced. If the whole sequence should play inside one rounded window, select the clips on the Edit page, right-click and choose New Compound Clip. Open that Compound Clip in Fusion and apply the Rectangle mask once.

This is the clean route for a demo reel, app walkthrough or montage inside a persistent device-style frame. Keep individual clips separate when their positions or radii must change independently. A Compound Clip creates another level of timing, so name it clearly and open it when you need to adjust the cuts inside.

An Adjustment Clip is not my first choice for this job. It processes everything beneath its time range, which can unintentionally include titles, backgrounds or overlays. The dedicated Adjustment Clips guide explains that top-down scope and when a shared timeline effect is the better tool.

Build a Rounded Color Card for Text

For a label or lower-third panel, start with a Fusion Background node rather than a Solid Color generator imported from the Edit page:

1. Add a Background node and choose the card color and alpha.
2. Select the Background node and add Rectangle1 to its blue mask input.
3. Set Width, Height and Corner Radius on Rectangle1.
4. Add Text+ and Merge the text over the rounded Background.
5. Connect the Merge output to MediaOut.

The result remains editable: you can change the fill, opacity, proportions and text without replacing an asset. For typography, layout and Text+ controls, continue with the DaVinci Resolve text guide.

Add a Border and Shadow That Follow the Radius

Build the border from a second rounded shape instead of applying an outline to the rectangular source. Duplicate Rectangle1, enlarge the duplicate slightly, and use it to mask a Background node set to the border color. Merge the rounded video over that larger background.

For a shadow, duplicate the outer rounded shape again, darken it, soften it and offset it behind the card. Keep the shadow on its own branch. Blurring the completed video branch softens the picture as well as the edge, which is rarely what you want.

When the Edit-Page Method Is Enough

For a one-off overlay, apply Resolve FX Transform from the Effects Library. In Resolve 21, enable Crop, then adjust Edge Rounding. Use Edge Softness only when the alpha edge needs feathering; it isn't the rounding control. This method is quicker than Fusion when one clip needs no reusable border or node branching.

Don't confuse that effect with the normal Inspector controls named Crop Left, Crop Right, Crop Top and Crop Bottom. Those controls remove straight strips; they don't create curved corners on their own. The Resolve Inspector control guide maps those clip-level transform and crop groups. Move back to Fusion when the effect is combined with stabilization, several transforms, animation or a reusable border. The node graph makes the processing order visible instead of forcing you to guess which crop happened first.

Round Only the Top or Bottom Corners

The standard Rectangle mask applies the same radius to all four corners. For a panel with only the top corners rounded, make the mask taller than the frame and move it down until the bottom curves sit outside the visible area. Reverse that placement for only the bottom corners.

For four independently controlled corners or a true squircle, combine multiple masks or use the Shape tools rather than fighting the standard Rectangle. Community threads about independent Fusion corner radii show why this becomes an expression-and-shape problem, not a hidden checkbox in Rectangle1.

Animate the Card Without Making the Edge Wobble

Width, Height, Center, and Corner Radius have keyframe controls. A clean entrance usually keeps Corner Radius fixed and animates Center or overall size. If Width and Height change by different proportions, the apparent curve can breathe. Treat that as a geometry observation and verify the rendered motion; Blackmagic doesn't document a fixed-pixel radius formula for Rectangle.

Set the final radius at the final card size, then preview the complete animation at normal speed. Use the Spline editor to ease the position or scale; don't add extra Corner Radius keyframes unless the design intentionally changes from square to rounded.

Export Rounded Corners with or Without Transparency

If the rounded video is already composited over its final background, export it normally. The transparency outside the mask has already been replaced by the lower track.

If another editor needs a file with real transparency, choose a delivery format and codec that expose alpha-channel export in your installed Resolve build, enable the alpha option, and test the rendered file by placing it over a bright color. Don't assume an H.264 MP4 will preserve transparency. For ordinary YouTube or social delivery, composite over the intended background first and use the settings in the Resolve export settings hub.

Fix the Five Problems That Waste the Most Time

The corners are black

The outside of the mask is transparent, but there is nothing underneath it. Put the rounded clip on V2 and a background on V1, or render to an alpha-capable format when the next application needs transparency.

The entire clip disappears

Select Rectangle1 and reset Width, Height and Center. Confirm that Invert is off and that the mask feeds MediaIn1’s blue input. A tiny, inverted or off-screen Rectangle can hide the whole frame.

The curves turn into ovals

A non-uniform transform is happening after the mask. Move the stretch or aspect-ratio change before Rectangle1, then set the mask at the final proportions.

The edge looks soft

Reduce Soft Edge and check the composition at delivery resolution. A small feather can hide aliasing; a large one makes a UI card look out of focus.

The mask works in Fusion but not in the timeline

Make sure you opened the same timeline clip whose Fusion composition you edited. Confirm MediaIn1 still reaches MediaOut1 and that no later Edit-page crop or transform hides the rounded boundary.

If this is your first effect built from clip geometry, the DaVinci Resolve tutorial roadmap places it after Inspector basics and before more complex Fusion work.

Rounded Corners in DaVinci Resolve: FAQ

Can I round corners in DaVinci Resolve Free?

Yes. The native Fusion Rectangle mask, Background, Merge, Transform and basic keyframe controls used here are available in the free edition.

Why does Corner Radius change when I resize the Rectangle?

Blackmagic lays out Corner Radius as a 0.0–1.0 Rectangle control but doesn't define a fixed-pixel formula. In practice, the same value can look different after Width or Height changes. Set final proportions first; use a Shape or expression workflow when dimensions animate.

Can I apply rounded corners to several clips at once?

Yes. Put the shots into a Compound Clip and apply one Fusion Rectangle mask to the compound. Keep them separate if each clip needs different framing or animation.

Can I round only two corners?

Extend the Rectangle beyond the frame so the unwanted curved corners sit outside the visible area. Use multiple masks or Shape tools when every corner needs independent control.

Why are my rounded corners uneven?

Check for non-uniform X/Y scaling after the mask. Apply that scaling before Rectangle1 and build the mask in the final image proportions.

How do I export rounded video with transparency?

Render with a format and codec that expose alpha-channel output in Resolve, enable alpha export, and verify the file over another color. Composite over the final background first when the delivery platform doesn't accept alpha.

Related guides

• Fusion in DaVinci Resolve: the hub: the rest of the Fusion cluster.
• DaVinci Resolve Fusion Tutorial for Beginners: the node basics behind this mask trick.
• How to Add Text in DaVinci Resolve: titles and lower thirds to pair with rounded frames.

Jason Miller I run DaVinci Resolve Club as an independent publication: hands-on edits, color grading breakdowns, Fairlight sessions, Fusion tests, and honest notes on where Resolve gets in the way.