01Sound on every clip
Kling 4 always renders audio with the video; there is no silent mode and no off switch. That suits clips you post straight away: footsteps on a wet street, a cheering crowd, a kettle starting to whistle. Write what should be heard next to what happens on screen, for example “rain on the window, no music”.
02First and last frame control
Add a first frame and a last frame, and Kling 4 generates the motion between them. Use it for a before-and-after, a room going from empty to furnished, or a product turning from front to back. Choose two photos of the same scene with the same aspect ratio, and let the prompt describe how the change happens.
03Animate photos in 2K
Add one image as the first frame and Kling 4 brings it to life, keeping your photo’s aspect ratio: a vertical phone shot makes a vertical clip, a wide landscape makes a wide one. Try a street portrait turning to the camera, a plate of food with rising steam, or a sleeping cat waking up. Your prompt only needs motion and sound.
04Five durations from 3 to 15 seconds
Choose 3, 5, 8, 10 or 15 seconds. Three seconds is enough to test a prompt, make a loop or a reaction; 15 seconds fits a short scene with setup and payoff. Write one idea per clip, open on the subject so the first frame already tells the story, and land the payoff before the last second.
05Four aspect ratios in text mode
Without an image, choose the frame yourself: 9:16 for TikTok, Reels and Shorts, 16:9 for YouTube, 1:1 for feeds, or 21:9 for cinematic widescreen. Every ratio works with every length from 3 to 15 seconds, always in 720p.
06720p for phones and social
Kling 4 renders every clip in 720p on this site, in all modes and at every length. With a single quality setting, you only choose the duration, plus the aspect ratio in text mode. On phones and social feeds, where most short videos are watched, 720p looks good.