How to change something inside a video with AI

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Swap a product, restyle a scene, change lighting or the look of an existing clip while keeping the motion. A step-by-step tutorial for Claude Code, Codex and Grok.

Output: The edited clip, same length and framing Price: in credits on varg, with a cost estimate before anything runs; the free skills below install in one command.

Recommended route

Best skills for this

  1. varg AI (varg-ai, varg, live) — Start here: Video-to-video on one key: Grok Imagine Video Edit, ID-V2V (keeps identity and motion), FLUX 3 v2v, ID-V2V Relight
  2. Runway Media (runway-media, Runway, live) — Alternative: Runway's video editing from chat (needs a Runway account) · Needs: Runway account
  3. Color Grade AI (color-grade-ai, Isaac Rowntree, beta) — Alternative: When a grade is enough for lighting or time of day
  4. Video Editing Best Practices (varg-video-editing, varg, live) — Adds: Which video-to-video model for which edit (swap, relight, restyle, extend) and how to splice the edited span back
    • Claude Code: claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg
    • Codex: npx skills add vargHQ/skills --skill varg-video-editing -a codex -y
    • Cursor: npx skills add vargHQ/skills --skill varg-video-editing -a cursor -y
    • Details: https://skills.varg.ai/skills/varg-video-editing.md
  5. Local-first video downloader: private, no subscription (media-download, varg, live) — Adds: Gets the source clip by link

Ask the person first

Put these choices in front of the person before spending anything. Paste the example link next to each option: people pick a look by seeing it.

What changes?

Clip length?

How to change something inside a video: step by step

  1. Trim to the part to change; split at calm moments (≤5 s Aleph, <10 s Kling Omni, ≤30 s Seedance 2.5)
  2. Edit the first frame as a still; attach references for new objects (design only)
  3. Prompt 'keep exactly … change only …', run video-to-video
  4. Check edges and seams, put the original audio back, export a before/after

What works now (researched 2026-10-27)

In-video editing went mainstream in 2026: Seedance 2.5 edit, Kling 3.0 Omni, Runway Aleph 2.0 and Genjutsu restyle keep the original acting, camera and sound and change only what you name. The edits people share most are before/after splits where the person stays and the world around them changes, not single object removals.

  1. Write the prompt as 'keep exactly, change only'. First list what must not change (duration, route, gestures, framing, lens, lighting, audio). Then list each change with its constraint, and end with 'everything not listed stays the same'. The 'status upgrade' edit used this structure (new outfit, house, garden and car, same walk) and got 240k views and 773 bookmarks; the full prompt is in the reply. (Matias S. Zavia on X, prompt for the Magnific motion-transfer edit (Sep 2026))
  2. Respect each model's input window and split long clips at calm moments where the subject is clearly visible. Aleph reads the first 5 s by default; Kling 3.0 Omni edit wants pieces under 10 s and at least 720 px; Seedance 2.5 edits up to 30 s in one pass. Runway's help center gives the 5 s default and the 64 MB limit; practitioners render Kling Omni in sub-10 s pieces with the same reference and prompt, then compare seams. (Runway Help Center, Aleph in the Edit Video app)
  3. Attach a reference image for any new product, prop or outfit, and say it is a design reference only, not a reference for the scene. Pick replacements that fit the original action (a car door that opens the same way). The status-upgrade edit attached the product photo as 'a product-design reference only' and chose a car with a conventional door so every hand movement still matched. (Matias S. Zavia on X, prompt reply (Sep 2026))
  4. Show the before. Post as a split screen or an 'ORIGINAL' then 'EDIT' cut. Use action verbs in the prompt: add, remove, restyle, relight. The top edit posts are all side by side. Runway's Aleph guidance recommends clear action verbs and reference images for style or lighting. (DataCamp, Runway Aleph tutorial)
  5. Keep the original sound. Join edited pieces without audio, then lay the source audio back on as one track. Re-generated audio drifts from lip and hand timing; the swap pipeline with 873 bookmarks does it this way. (Chris (@everestchris6) on X, edit pipeline (Oct 2026))

Stopped working:

Prompts that work

Templates from the creators of the best current results and from the model guides. Fill in the {CAPS}.

Keep exactly, change only (any)

Video-to-video edit of your own take (Seedance 2.5 edit, Kling Omni edit or grok_imagine_edit): new outfit, space, car or product, same walk and audio. Adapted from Matias S. Zavia on X, full prompt for the status-upgrade edit (Sep 2026).

Use the uploaded video as the exact source for timing, choreography, subject identity, composition, spatial continuity and camera movement. It is not loose inspiration. Reproduce the same continuous take frame by frame: identical duration, action, route, gestures, expression, gaze, body position, handheld motion, lens, framing, focus, lighting direction and original audio.
Preserve {SUBJECT}'s identity perfectly: same face, age, hair, {GLASSES_OR_FACIAL_HAIR}, body shape. Only change the clothing: {NEW_OUTFIT}. No visible logos. The clothes stay identical in every frame.
Upgrade the {SPACE} without changing its architecture, layout, doors, stairs or the route: {NEW_MATERIALS_AND_FURNITURE}.
Replace only the {OBJECT} the subject {TOUCHES_OR_ENTERS} with {NEW_OBJECT}, in the same position and orientation, opened and handled the same way, so every hand movement still matches.
When {ORIGINAL_PRODUCT} appears, replace it with the product in the attached image. The image is a product-design reference only, not a reference for the environment or the opening frame. Keep its real scale.
Photorealistic live action. No new shots, cuts, zooms, stabilization, slow motion or altered timing. No identity drift, flickering clothes, warped architecture, object popping, malformed hands, illegible text, added logos or watermarks. All elements not explicitly listed above must remain unchanged.

Restyle from an edited first frame (id_v2v)

Change the world or light around a performance: edit frame 0 as a still, then id_v2v carries the look through the clip and keeps faces, gaze and motion. Adapted from Eyeline Labs, ID-V2V README and sample prompts (GitHub).

STEP 1, edit frame 0 of the source as a still (image edit model, frame attached):
Keep the camera, framing, lens and the people exactly as they are: same faces, pose, expression, gaze and clothing. Change only {WHAT_CHANGES: the room into ..., the time of day to ..., the look to ...}. Match the original perspective and the direction of light on the people. No new people, no text.

STEP 2, video (source video + the edited still as the first frame):
{NEW_SETTING_AND_LIGHT_IN_ONE_SENTENCE}. {SUBJECT_A: hair, clothing} and {SUBJECT_B: hair, clothing} {BEAT_1_AS_IN_THE_SOURCE}. {BEAT_2}. {BEAT_3}. {HOW_THE_NEW_LIGHT_FALLS_ON_THEM}, creating {MOOD}.

Write step 2 as the new world plus the performance in the order it happens in the source. Do not describe a different action: the source owns the motion.

Trending formats to remake

To remake one: download the example with the media-download skill, take a frame a second and the transcript, write a beat list (time, shot, camera, on-screen text, sound), keep what the format needs, swap in the person's product or character (never the creator's face, voice, logo or footage), show the beat list and stills before spending, then make it with the skill named below.

  1. Everything but me: The same phone take of you walking through your place, re-rendered with an upgraded home, outfit, garden and car, shown as a split with the original. Why it spreads: Identity and motion stay, so it reads as real and makes people ask how. 240k views and 773 bookmarks, with the full prompt shared in the replies. Keep: One phone take of you walking through your own place, the same route, gestures and timing, change only outfit, house, garden and car (each with a constraint), shown as a split with the original and the original audio. Swap what gets upgraded. Make it with varg AI (varg-ai).
  2. Masked restyle reveal: Only part of the frame is restyled: a moving mask reveals a different look of the same footage underneath, so original and edit share one shot. Why it spreads: It shows the edit without a split screen and works as a website hero or a transition. 681 bookmarks on 40k views (save ratio 0.87). Keep: One clip rendered twice (original and restyled, same motion and frame count, aligned) and a moving mask in code that reveals the restyle; swap the footage and the look. Make it with varg AI (varg-ai).
  3. Swap the product in a winning ad: Take an ad that already performs and replace only the product, packaging or outfit, keeping every cut, line and camera move. Why it spreads: Brands and agents now sell this as a one-step skill (Scenario's 'film it once, change it later' skill drew 1,082 bookmarks), but public examples are tool promos, so none pass yet. Keep: Every cut, line and camera move of the ad; only the product changes, attached as a design reference only, picked to be the same size and handled the same way; edit per shot and lay the original audio back. Make it with varg AI (varg-ai).

Open-source repos

Set up varg

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