How to Turn a Day Video into Night with AI

To turn a day video into night with AI, render the clip again with the time of day changed and everything else kept: the sky goes dark, windows and lamps light up, and the person, the moves, the framing and the timing stay where they were. We tested it on two clips we made ourselves. On one continuous shot, the whole clip turned to night. On a clip with 12 shots, Seedance 2.0 turned only the first shot and Seedance 2.5 turned half of them. A disclosure first: we make Riffkit, whose Swap mode does the re-render.

Three ways to make a day video look like night

Pick by what you need. If a darker, bluer version of your clip is enough, a grade in your editor is quick and keeps every pixel. If you need a real night, with a dark sky, lit windows and lamps on, in a clip you already have, a re-render can get it without filming again: on our one-shot clip it did, and on a clip with cuts you need to check every shot.

Test 1: one continuous shot, from an overcast day to night

The source is a 5-second clip we made with AI: one continuous, low handheld shot of a woman in a navy blazer running toward the camera across an office plaza, under a glass canopy, with glass towers and a white overcast sky behind her and a caption burned in. We asked for night and nothing else. We used Swap on Seedance 2.0 at 720p. It was billed as 6 seconds, 720 credits, and took about 10 minutes from submit to finished video, including the analysis of a new clip.

What changed as asked. The white sky became a dark night sky, the office windows in the towers lit up, and the lights under the glass canopy came on. A few night details we didn't ask for came with it: red lights on the far rooftops and lit trees at the end of the plaza.

What stayed. Her face and expression, the blazer, the bun, the gold chain, the run, the low angle, the framing and the caption, in the same place, in every frame we checked where she is in shot. The sound came back unchanged: Swap kept the clip's original track.

What drifted. We asked for cool city light on her face and blazer, and it didn't land: the light on her face and the pavement stayed almost as bright as in the daytime original, so up close she looks lit for day against a night sky. The towers also picked up white light strips along their edges that the original doesn't have.

Test 2: a clip with 12 shots

A week earlier we ran the same kind of change on a 13-second clip we made with AI: a woman's office day in 12 shots, at desks, in a store, by a river at dusk, and close-ups of hands and a drink can. We asked for night in every shot, with lit buildings outside the windows, the overhead lights off and warm desk lamps on. Swap on Seedance 2.0 at 720p was billed as 13 seconds, 1,560 credits.

What happened. Only the first shot turned to night: the office behind her became a lit night skyline. The other 11 shots stayed as they were in the original (daylight, and dusk by the river), and in two of them her beige sweater was replaced by the black jacket from the first shot. Every cut stayed in place, within one frame.

A re-run on Seedance 2.5 the same day turned 3 of the 12 shots to night, the ones with a window behind her. That was before an engine update that changed how Seedance 2.5 handles light and time-of-day changes.

On October 26 we ran the clip again on Seedance 2.0, at 480p, with a request written for the whole video. It opened "The whole video, from the first shot to the last, changes from day to night" and asked to keep the outfit in each shot exactly as it was in that shot. It was billed as 13 seconds, 780 credits. The first shot turned to night again, two more moved toward evening (bluer windows behind her in one, a darker dusk sky by the river in the other), and the other nine stayed as they were. This time no outfit moved from one shot to another.

The same evening we ran that request on Seedance 2.5 at 480p, after the engine update. It was billed as 13 seconds, 1,170 credits. Six of the 12 shots turned to night: the ones where a window or the room shows behind her. A close-up of the can got dimmer, four shots stayed as they were (a bag on a counter, an e-reader close-up, a hand on a mouse, the riverside at dusk), and the store shot came back as a different store. No outfit moved.

How to change a video from day to night with Swap

1. Open Swap. It's the first card on the Make videos page.

2. Add the clip. Upload a file up to 100 MB, paste a TikTok link to your own post, or pick a template. Swap keeps the full length, up to 45 seconds, so trim a longer clip first.

3. Write the change in "What to change". Name the new time of day and what the light should do, then say what must stay. This is the line we used in the first test, word for word:

   Change only the time of day: the same plaza at night. The pale overcast sky becomes a dark night sky, the office windows in the glass towers are lit, the lights under the glass canopy are on, and cool city light falls on her face and her blazer. Keep everything else exactly as it is: the same woman, her face and her hair blown up by the wind, the navy blazer, dark shirt and gold chain, her run toward and past the camera, the low handheld angle, the framing, the timing, and the caption text and its position. Add nothing else: no rain, no extra people.

4. Name the lights you want on, then check each one. Our request named the sky, the office windows, the canopy lights and cool light on her face. The first three changed; the light on her face stayed close to daytime.

5. Check the price and submit. The page shows the rate per second, then the billed seconds and credit total, before you tap Riff it →. For a new upload it is an estimate until Riffkit has the file.

6. Compare it with the original. Watch every shot, and look at the people and the ground as well as the sky.

Working in a chat instead? The same change runs from Claude or ChatGPT through the Riffkit connector; how to make videos in ChatGPT and Claude has the setup.

What you can do for free

• No card. New accounts start with signup credits, and the page shows what a Swap costs before you spend them.
• Engines. Free accounts Swap at 480p, on Seedance 2.0 Fast or Seedance 2.0.
• Length. A short clip comes back whole; a clip with more than one section gets its first section free, and a plan finishes the rest.
• Watermark. Free videos carry a small Riffkit watermark, and any plan removes it.

Seedance 2.5, 720p and 1080p come with a plan, from $15 a month for 3,000 credits. Swap bills per second of finished video, from 50 credits a second on Seedance 2.0 Fast at 480p, and failed renders aren't charged.

Limits to know before you start

• On a clip with cuts, check every shot. On our 12-shot clip, Seedance 2.5 turned the most shots to night (6 of 12, the ones with a window or a room behind her); Seedance 2.0 turned only the first shot, in two runs. Close-ups with no window in them kept their daytime light. Our one-shot clip turned to night from start to finish, so if one shot matters most, trim it out and run that shot on its own.
• Name each shot's outfit in what must stay. In our first run on the 12-shot clip, a jacket from the first shot showed up in two others; in the second, the request kept the outfit in each shot as it was, and none moved.
• People can stay lit for day. In the first test the light on her face and the pavement stayed close to daytime, so a close-up can look pasted onto the night. Compare a close-up frame with the original before you post.
• Everything is drawn again. Small details can appear or shift, like the light strips on the towers in our first test.
• Storefronts, property exteriors and product close-ups are untested. If your clip is one of these, name the product, its label and its colors in what must stay, and check signs and labels in every frame.
• Use footage you own. Swap is for your own videos and templates; someone else's video still belongs to them. Where the line sits.

To move a clip to a different place rather than a different time, see how to change a video's background with AI, and to change only the color of what someone wears, how to change the color of clothes in a video.