How to Edit an Existing Video with AI Prompts

Prompt-based video editing works differently from a traditional timeline editor. You do not cut, key, or mask anything — you upload a clip you already have, describe the change in plain language, and the model re-renders the clip with that change applied. This guide walks through the full workflow and the constraints that decide whether your edit succeeds.

What "editing" means here

The editor is built to keep your source clip's duration and framing: an 8-second clip in, an 8-second clip out, one described difference on top of the same shot. That is the strength of the approach — the result is meant to be compared with the original, side by side. "Meant to" is doing real work in that sentence: the model re-renders every frame, so the framing and camera move stay close but are not guaranteed pixel-exact. Checking an edit includes watching for drift in what should have stayed unchanged (step 4 covers how).

It is not a general-purpose editor. Trimming, resizing, subtitles, audio cleanup, and multi-track timelines are not part of this workflow. If you need those, do them in a conventional editor first, then bring the finished short clip here.

Step 1: Upload the source clip

Requirements are strict, and they exist for a reason:

• Format: MP4
• Length: 1–15 seconds
• Size: up to 50 MB

Long videos must be cut down first. Before anything runs, the clip is previewed in the studio so you can confirm you uploaded the right file — and the duration used for billing is verified server-side from the actual file, not from what the browser reports.

Step 2: Describe one change

The prompt field is where the edit happens. Two rules make the difference between a usable result and a wasted one:

1. Change one thing per pass. "Make the car red" is a well-scoped edit. "Make the car red, remove the reflection, and add a sunset" is three edits fighting each other in a single generation.
2. Name what must stay the same. Models drift when nothing anchors them. "Keep the windows, wheels, lights, camera movement, and timing unchanged" tells the model what the edit is not allowed to touch.

A practical starting structure:

Change only <the one thing>.

Keep <subject parts, scene, camera movement, timing> unchanged.
Maintain natural <reflections / shadows / lighting>.

The prompt library has filled-in templates for color, background, and style changes.

Step 3: Draft first, then final

The studio offers two quality modes for edits:

• Draft — fewer credits, meant for testing whether the prompt does what you intended.
• Final — more credits, the version you publish.

The exact credit cost is quoted before you submit and depends on duration and mode; nothing is charged without the quote being shown first. If a task fails or is cancelled, the reserved credits are refunded.

A sensible loop: draft → watch the comparison → adjust one factor in the prompt → draft again. Only switch to final when the draft already looks close.

Step 4: Compare against the original

The result player shows the original and the edited clip side by side, kept in sync. Use it deliberately:

• Check the thing you asked for. Did the color actually change? Everywhere, or only in some frames?
• Check what you told the model to keep. Windows, wheels, logos, background objects — drift here is the most common failure.
• Watch for flicker on clips with fast motion or a busy scene; both are hard for current models.

If the result is wrong, change one factor and re-run. Iterating two variables at once means you cannot tell which change caused the improvement.

When this workflow is the wrong tool

Be honest about the inputs. Prompt editing struggles with:

• fast subject motion or a cluttered scene
• multiple similar colors when you only want one changed
• subjects that leave the frame
• edits that require pixel-exact precision (brand colors, UI screenshots)

For creating footage that does not exist at all — rather than changing an existing clip — text-to-video and image-to-video are the right entry points, and the difference matters for what you can honestly claim the output is.

Start editing

Open the video editor, upload a 1–15 second clip, and describe one change. Credit plans are on the pricing page, and the quote is always shown before you submit.