Kling V4 AI Video Generation

Kling V4 is the newest video model in Kuaishou's Kling line, added to FlyAIgh in October 2026. Its headline change is length: one generation runs any whole number of seconds from 3 to 30, so a walk-and-talk, a slow reveal or a product turn can stay in a single take instead of being stitched from shorter clips. Kling V3 and V3 Omni stop at 15 seconds. Kuaishou describes V4 as built for larger motion, complex camera moves, steadier emotion on faces and legible on-screen text.

Every clip comes back with stereo sound. There is no switch for it — sound is part of the render and part of the price. Output is 720p or 1080p. Text-to-video and the reference mode offer 16:9, 9:16, 1:1 and 21:9; image-to-video keeps the framing of your image.

There are three ways to drive it. Text-to-video works from a prompt alone, and prompts can run long — up to 11,000 characters — which helps when a 30-second take needs its beats written out. Image-to-video starts from your first frame, and you can add a last frame so the shot lands on a pose you chose. The reference mode takes up to 10 images and up to 5 reference videos, 30 seconds of video in total, to fix a character, a costume, a set, a camera move or a rhythm from real material instead of description.

Without a reference video, Kling V4 costs 12.7 credits per second at 720p: 64 credits for 5 seconds, 127 for 10 and 381 for a full 30-second take. At 1080p a 5-second clip is 97 credits and 30 seconds is 582. Attaching a reference video changes how the supplier bills: you pay for the output length plus the longer of the reference and the output, at 7.4 credits a second at 720p or 11.3 at 1080p. A 10-second 720p clip guided by a 6-second reference costs 148 credits; a 5-second clip guided by a 12-second reference costs 126. The generator shows the exact total before you start.

Pick Kling V4 for long single takes, for shots that need a reference video, or when you want sound without a second pass. For shorter clips, Kling V3 is the cheaper Kling at 8 credits a second, and Kling V3 Omni adds a 4K tier and up to 7 reference images; both have their own pages. Like every model on FlyAIgh, V4 runs on the same credit wallet — no Kuaishou account or China-mainland phone number.