How to widen a vertical video without cropping or black bars

Last updated 2026-09-01 · 8 min read

What is the short version?

A vertical clip in a landscape slot normally gets one of two bad treatments: cropped, so half the subject leaves, or letterboxed, so two thirds of the frame is black. Generating the missing sides is the third option.

1. Go to Vizard Agent and upload the vertical clip.
2. Say the shape you need it in.
3. Say what must stay exactly as filmed — usually the subject.

What do you need before you start?

The clip and the destination. Vizard Agent generates the sides to match what is already in the frame, so a shot with a simple, continuous background — a wall, a sky, a crowd — extends far more convincingly than one with detail running off the edge.

• The clip. As filmed, at full resolution.
• The target shape. 16:9, square, or a specific size.
• The untouched area. The original frame, always.
• The setting. So the extension matches it.
• The length. Longer clips mean more to keep consistent.

What do you type into Vizard Agent?

Use the word extend rather than the word fit. Vizard Agent will otherwise crop the frame or pad it out, because those are the two safe and reversible answers — and asking explicitly for the sides to be generated is the only thing that gets you the third option.

Prompt

Variants worth knowing:

• "Extend the sides." Not "make it landscape".
• "Do not crop." Otherwise it may choose the safe route.
• Name the destination. The exact size follows from it.

What does Vizard Agent actually do?

Here is the order Vizard Agent worked in on a real frame extension for a video that had to fit a landscape post. Notice what happens in the middle of it: rather than trusting a single image generator, it produces the extension twice with two different models and compares them.

1. Checks the video's dimensions and the tools available.
2. Extracts sample frames and inspects the footage.
3. Reviews a sample frame to see what is at the edges.
4. Checks the image generation options.
5. Samples frames across the whole timeline and reviews them tiled.
6. Transcribes the shots to understand what changes across the clip.
7. Uploads a sample frame as the reference for the extension.
8. Prepares a 16:9 canvas with padded sides to generate into.
9. Generates the extended background with an image editor.
10. Reviews the generated extension at full size.
11. Generates an alternative extension with a different model and reads that one too.
12. Checks the dimensions of both generated images.
13. Tests the alignment and composite and views the result directly.
14. Inspects the raw background dimensions and the generated image shape.
15. Generates test composites for the different scenes in the clip.

Step eleven is the practical bit. Frame extension is exactly the task where two generators give noticeably different results on the same footage, so Vizard Agent produces both and looks at them rather than accepting the first.

What does the result look like?

The clip this page is written from was a vertical video extended to fill a 16:9 frame: the original footage untouched down the centre, generated background running out to both edges, matched to the setting rather than blurred.

The common shortcut is a blurred, scaled-up copy of the video behind itself. That reads as a workaround. A generated extension that matches the room reads as a wider shot.

When does this not work well?

The extension has to invent whatever was sitting just outside the camera's view when you filmed, and there are several kinds of shot where that simply cannot be done convincingly. These are the ones where cropping is the better answer.

• Detail running off the edge. A face or a sign half out of frame.
• Camera movement. The extension has to move with it.
• Changing scenes. Each one needs its own extension.
• Recognisable places. Invented architecture will be noticed.
• Long clips. Consistency gets harder the longer it runs.

How do you fix a result that came back wrong?

Say what the generated extension got wrong and on which side. Vizard Agent keeps the reference frames, both generated versions and all the alignment tests it ran, so a corrected side is a re-composite from existing material rather than starting the clip over.

• "The wall does not line up." Regenerated from the same reference.
• "It invented a doorway." Extension simplified to plain background.
• "The seam shows." Alignment re-tested and the blend widened.

How does Vizard Agent compare to doing it yourself?

By hand you crop, letterbox, or blur a copy behind it — those are the three options an editor has. Vizard Agent generates the sides, tests two models against your actual footage, and checks the seam on real frames.

Common questions

Does it crop my video at all? No. Vizard Agent keeps the original frame intact and builds outwards from it.

Is this better than a blurred background? Usually. A blurred copy is instantly recognisable as a workaround.

Will the seam show? It tests for that. Vizard Agent composites real frames and inspects the join.

What shapes can it target? Any. Vizard Agent extends to 16:9, square, or a specific pixel size.

Does it work with camera movement? Less well. Vizard Agent will tell you when the shot moves too much.

What about several scenes in one clip? Each needs its own extension. Vizard Agent generates and tests them separately.

Can it extend the top and bottom instead? Yes. Vizard Agent extends whichever edges the target shape needs.

Why generate twice? Because models differ on the same footage. Vizard Agent compares rather than assuming.

Is the extension real? No — it is generated. For a recognisable location, say so or crop instead.

Can I keep a version of both? Yes. Vizard Agent can deliver the extended and the cropped version together.

When should I just crop? When the shot is a close-up with nothing at the edges worth keeping, or when the location is identifiable and an invented background would misrepresent it.

Does it work on a still image? Yes, and considerably more easily. A single frame has no consistency problem to solve across time.

Will the extension move with the shot? It has to, and that is the hard part. Vizard Agent tells you when the camera moves too much for the extension to hold.

Can it match a specific background colour? Yes. Vizard Agent can extend into a flat colour or a gradient instead of generating scenery, which is often the safer choice for a studio shot.

Does it check the result? Yes. Vizard Agent builds test composites across each of the clip's scenes and inspects them before committing to a render.

Can it extend a whole long video? Yes, though it gets harder. Vizard Agent generates per scene and checks each join.