Kling 4.0 AI Video Generator

Kling is the video model family of Kuaishou, the Chinese short-video company. Version 4 reached the Kie.ai API, the provider AgentReel uses, at the start of November 2026. Kie.ai's model page highlights native stereo audio with better lip sync, more stable fast motion and camera moves, clearer text and logos in the frame, and support for several languages and accents.

The upstream model can do more than AgentReel exposes today. Kie.ai lists clips of 3 to 30 seconds, up to 10 keyframes and an Omni Reference mode with up to 15 images, videos, voices and subjects. On AgentReel you get text-to-video and first-and-last-frame video at 5s, 10s, 15s; reference mode and video input may follow later. Kuaishou lists 4K and 10-bit HDR as coming soon, so neither is offered yet.

Sources: Kie.ai Kling 4.0 model page, API docs for kling-4.0/keyframe-to-video and the Kie.ai pricing page, all read on 2 November 2026.

Write one shot: the subject, the action, the camera and the light. "A cyclist sprints through a neon tunnel at night, low tracking shot, wet asphalt reflecting pink light, the hum of the bike and distant traffic" gives the model a subject, a motion, a camera move and a soundscape. Because audio is always generated, a few words about sound pay off.

When you use frames, do not describe the pictures again. Describe what changes between them. Kie's API refers to the pictures as @first_frame and @last_frame; AgentReel adds those names to your prompt automatically when you leave them out, so you can write plain sentences.

The 720p tier is the default and the better choice for drafts and social clips. Move to 1080p for a final render, a large screen or a shot you will crop. Both take the same prompt and frames.

Length is the setting that moves the price most. A reveal or a gesture fits in the shortest option; a walk through a room or a long camera move needs more. Start short, check the motion, then render the long version.

On AgentReel a clip costs 36 to 160 credits. The price follows the per-second rate of the resolution times the duration, and the table on this page lists every combination. A failed clip is refunded automatically.

Credits come from a plan or credit pack. Free check-in credits do not pay for AI video. The credits and pricing guide explains plans and packs.

Choose Kling 3.0 when you want a sound switch, more length options or a lower price per second; it remains a strong model for silent clips. Pick the new version when sound matters, when the shot has fast action, or when you want a planned first and last frame with audio.

Veo 3.1 is priced per 8-second clip and reaches 4K; Seedance 2.5 has wider ratios and long prompts; Vidu Q4 builds a scene from up to 15 reference images. The model overview has a page for each one, and all of them run in the same generator.