Prompt Gemini Omni for video editing

Last updated: October 12, 2026

Gemini Omni changes one thing in a clip you already have (an effect, a prop, the lighting, the whole look) and keeps the motion, timing and framing you approved. Pick it when the animation is right and only the look needs to change.

Let the agent write it

You don't have to write any of this yourself. The Layer agent knows how to prompt each model it runs, from the same guidance this page is built on. Attach the clip in chat, name the model and say what should change, for example: Edit this with Gemini Omni Flash 1.1: turn the fire magic into ice, keep everything else. The agent writes the prompt, shows you its plan, and runs it when you approve. Use the rest of this guide when you want to write or adjust the prompt yourself, and see Write a brief for the agent for how to brief it.

When to use it

Use Gemini Omni to make variants of an approved clip: an element swap for an enemy type (fire to ice, sword to axe), a new time of day, a regrade, or a full reskin of a scene. The edit plays the same motion on the same beats as the source, so a variant drops into the same slot in the game or the cut.

It is not the tool for changing what happens: the motion stays. To animate a still into a new clip, see Prompt Seedance for image-to-video or Create a video.

Versions on Layer

Gemini Omni Flash 1.1

The version this guide's examples were made with, and the newer of the two.

Gemini Omni Flash

The first release. In our test the same prompt gave a near-identical edit to 1.1, with the ice blast filling more of the last frames.

How to write the prompt

One sentence for the change, then one for what stays:

Change the fire magic to blue ice magic. Keep everything else the same.

The clip already holds the character, the scene, the camera and the motion, so the prompt only names what is different. Every detail you add is one more thing the model redraws. That prompt is the one in the clip above.

What works

Short, one-change prompts

Write the edit the way you would ask a colleague: "Change the lighting to be more dramatic", "Put a hood on him", "Change the fire magic to blue ice magic". In our test the short prompt swapped the fire for ice on the staff and in the blast, and kept the sunset, the castle and the cloak. A long prompt that listed every frost detail landed each one, and also frosted the cloak's hem, which it did not ask for.

The motion stays

Every edit we ran came back the same length and shape as the source, with the mage raising the staff, swinging it and casting on the same beats. You can rely on that to make a set of variants that cut against each other.

Keep everything else the same

End the edit with "Keep everything else the same", as Google's guide recommends. On our one-change edit it made no visible difference, but it costs nothing and protects the parts you did not mention.

One change per run

Make one change, check it, then edit the result for the next one. Each edit carries the earlier ones forward, and you can see which change caused what.

Whole-clip looks in one line

A regrade, a new time of day or a new material works from the same short form: "Make it a snowy night. Keep everything else the same."

Sound with the edit

The edit comes back with sound. Ask for what you want to hear the way you would when generating, for example "add the crackle of ice forming".

What to avoid

Expecting a keep line to stop new light

A new effect lights what is near it. In our test the ice turned the mage's face pale blue, and adding "Keep his face, the red cloak, the sunset sky and the camera exactly as they are" did not change that: the cloak, sky and camera stayed either way, and the face still took the cold light. Plan for the new effect's colour to fall on the faces and surfaces around it.

Long, descriptive edit prompts

The more you describe, the more the clip changes, including details you did not ask for. If you want a full reskin, say so and list it; otherwise keep to the one change.

Editing speech

Gemini Omni cannot edit a voice or add dialogue over a clip that already has speech. Edit a clip without speech, and add the voice afterwards.

Settings that matter

Video to edit is the clip the edit starts from; source clips run up to 10 seconds. The edit keeps the clip's length and shape, so there is no duration or aspect ratio to set. Above the prompt, Camera, Staging, Look and Performance take reference sets for each.

Prompts to start from

Swap an effect

Change the fire magic to blue ice magic. Keep everything else the same.

Full reskin of a scene

Transform this into a frost mage scene: the glowing ember on the staff becomes a jagged crystal of pale blue ice radiating cold mist, the fireball he launches becomes a spinning shard of ice trailing frost particles and snowflakes, the warm orange light on his face and cloak turns to a cold cyan glow, frost creeps across the mossy stones under his feet, his breath fogs in the cold air, and the sky behind him shifts to a wintry twilight with drifting snow. Keep everything else the same.

Use it in Layer

  1. Add the clip to a session's board.

  2. Click View on the clip. The edit bar sits under it; Prompt edit video in the tools list points to the same bar.

  3. Click the model name in the bar and choose Gemini Omni Flash 1.1.

  4. Write the change, then "Keep everything else the same."

  5. Click Edit video. The cost shows on the button before you click.

  6. The edit joins the clip's edit group and plays in the viewer. Compare it with the source, then edit the result for the next change.

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