Kling 4.0 is the new flagship AI video model from Kuaishou's Kling AI. A lighter Kling 4.0 Flash opened to a small group of users for early access on September 28, 2026, and Kuaishou set the full launch for October 2026. The headline change: Kling 4.0 generates up to 30 seconds of video with sound in a single pass — twice as long as Kling 3.0 — and gives you much more control over characters, references and edits.
This guide explains what Kling 4.0 is, what changed from Kling 3.0, what it costs on SeeVid, and how to use each mode.
What Is Kling 4.0?
Kling 4.0 is a multimodal video model: it turns a text prompt, images or existing video clips into a new video, with audio generated in the same pass. Kling describes the release as more than a quality bump — the focus is on longer takes and more control: more keyframes, more reference inputs, steadier motion and editing that is built into the model.
On SeeVid, Kling 4.0 runs in four modes:
| Mode | What you give it | What you get |
|---|---|---|
| Text-to-video | A prompt | A 3–30 s clip in 16:9, 9:16, 1:1 or 21:9 |
| Image-to-video | A first frame (and optionally a last frame) | A clip that starts from your image |
| Reference-to-video | Up to 10 images and 5 videos | A new clip that keeps your characters, products or style |
| Video edit | One video (3–30 s) plus up to 10 reference images | Your video with the changes you describe |
What's New in Kling 4.0 vs Kling 3.0
| Kling 3.0 | Kling 4.0 | |
|---|---|---|
| Clip length | 3–15 s | 3–30 s in one pass |
| Audio | Single-channel, lip sync | Two-channel stereo, improved lip sync |
| Lip-sync languages | Chinese, English, Japanese, Korean, Spanish | Adds Portuguese, German, French, Hindi and more, plus accents and dialects |
| Keyframes | Start and end frame | Up to 10 keyframes |
| References | Up to 7 images, or 1 video (max 15 s) + 4 images | Up to 15 reference assets: 10 images, 5 videos (30 s total), plus voice |
| Video editing | Through Omni workflows | Built in: up to 5 input clips, 30 s total |
| Output | Up to 4K, 8-bit SDR | Up to 4K with 10-bit HDR at 1080p and 4K |
| Aspect ratios | 16:9, 9:16, 1:1 | Adds 21:9 ultrawide |
Specs as published by Kling. Some features — 4K, HDR, more than two keyframes and voice references — are not available on every platform yet; see "Kling 4.0 on SeeVid" below.
1. 30-second clips in one pass
Kling 3.0 topped out at 15 seconds, so longer scenes had to be stitched from several clips — and characters, lighting and camera often drifted between them. Kling 4.0 generates up to 30 seconds at once, which keeps a whole ad, product demo or story beat consistent.
2. Stereo sound and better lip sync
Audio moves from mono to two-channel stereo, and lip sync is more accurate. Kling also added more languages for speech — Portuguese, German, French and Hindi among them — and accents such as British and Indian English, Cantonese and Sichuanese.
3. More references, steadier characters
Omni Reference now takes up to 15 assets: up to 10 images, up to 5 videos (30 seconds in total) and voice. You can lock several characters, a product and a style in one generation, which matters most in longer clips where faces and outfits tend to drift.
4. Steadier motion and camera work
Kling says tracking shots, orbits, fast action and continuous body movement — fights, sports, dance, vehicles — stay more stable and connected. It also improves detail in faces, materials and lighting, and renders text, logos and emoji more accurately.
5. Video editing built in
Kling 4.0 can edit an existing video directly: change expressions, movement, backgrounds, camera angle, style, weather, colours or materials while keeping the rest. Creative Recreation reuses a video's pacing and structure with new subjects.
Kling 4.0 on SeeVid
SeeVid runs Kling 4.0 through Kuaishou's API, next to Seedance, Veo, Wan and other models with one credit balance. What you can use today:
- Length: 3–30 seconds in every mode.
- Quality: 720p or 1080p.
- Aspect ratios (text-to-video): 16:9, 9:16, 1:1 and 21:9. Image-to-video follows your image.
- Image-to-video: a first frame, plus an optional last frame.
- Reference-to-video: up to 10 images and 5 videos, 30 seconds of video in total.
- Video edit: one source video of 3–30 seconds plus up to 10 reference images; the output length follows the source by default.
- Prompts: up to 2,500 characters.
- Sound: generated with every clip and included in the price.
4K, 10-bit HDR, more than two keyframes and voice references are not offered on SeeVid yet.
Kling 4.0 Pricing on SeeVid
Kling 4.0 is billed per second of output, with sound included:
| Length | 720p | 1080p |
|---|---|---|
| 5 seconds | 59 credits | 88 credits |
| 10 seconds | 117 credits | 176 credits |
| 15 seconds | 176 credits | 264 credits |
| 30 seconds | 352 credits | 528 credits |
Prices as of November 2026. The generator always shows the current price before you generate.
These prices apply to text-to-video, image-to-video and reference-to-video without a reference video. When you add a reference video, or edit a video, the source length is billed too at a lower rate — so editing a clip costs more than generating one of the same length. The exact price always shows on the Generate button before you start.
In dollars, credits cost about $0.025 each on the Basic pack ($20 / 800 credits), $0.022 on the Pro pack and $0.020 on the Studio pack or the Pro monthly plan. A 10-second 720p Kling 4.0 clip is therefore about $2.35–2.95, and a full 30-second 1080p take about $10.55–13.20. See pricing for all plans.
For comparison, Kling 3.0 on SeeVid costs about half as much per second, but capped at 15 seconds and without the new reference and editing features.
How to Use Kling 4.0
Text-to-video
- Open the AI Video Generator and choose Kling 4.0.
- Write your prompt: subject, action, setting, camera and sound.
- Pick the aspect ratio, a length from 3 to 30 seconds and the quality, then generate.
A barista in a sunlit café pours latte art in slow motion, then slides the cup across the counter and smiles at the camera. Slow dolly-in, shallow depth of field, warm morning light. Sound: espresso machine hiss, soft jazz, quiet café chatter.
Image-to-video
Switch to Image to Video, upload your first frame and, if you want to control where the shot ends, a last frame. The image sets the look, so use the prompt for motion, camera and sound.
Reference-to-video
Use reference-to-video when the same character, product or style must appear in a new scene. Upload up to 10 images and 5 videos, then say in the prompt what each one is for — "the woman from image 1", "the sneakers from image 2", "the camera move from video 1".
Video edit
Upload a clip of 3–30 seconds and describe only what should change: "Replace the cloudy sky with a sunset and make the jacket red leather. Keep everything else the same." One clear change per run gives the most reliable results.
Prompting tips
- Use the length. A 30-second clip can hold several beats — describe them in order ("First… then… finally…").
- Write the sound. Name the music, effects and any dialogue; put spoken lines in quotes.
- Name the camera. "Slow orbit", "handheld tracking shot" or "locked-off wide shot" steer the result more than adjectives.
- Start short, then scale. Test a 5-second 720p version, then generate the full length at 1080p.
Kling 4.0 vs Seedance 2.5
Both generate 30-second clips with sound. Kling 4.0 is the better value: stereo audio, solid references and editing at about 35–45% less per second than Seedance 2.5. Seedance 2.5 gives the most control — up to 30 reference images and 10 videos, an extender and a draft mode — at a higher price. Our Seedance 2.5 vs Kling 4.0 vs Veo 3.1 vs Wan 3.0 comparison goes through them side by side.
Best Use Cases
- Ads and product videos that need one continuous 15–30 second take.
- Short story scenes with a recurring character, using reference-to-video.
- Talking-head and dialogue clips in more languages, thanks to stereo audio and better lip sync.
- Fixing or restyling footage with video edit instead of reshooting.
- Cinematic 21:9 shots for trailers and intros.
Frequently Asked Questions
When was Kling 4.0 released? Kling 4.0 Flash opened for early access on September 28, 2026, and Kuaishou set the full launch for October 2026.
How long can a Kling 4.0 video be? Up to 30 seconds in a single generation, from a minimum of 3 seconds.
Does Kling 4.0 generate sound? Yes. Every clip comes with two-channel stereo audio — music, effects and speech with lip sync. On SeeVid, sound is included in the price.
Can I use Kling 4.0 in 4K? Kling lists 4K and 10-bit HDR output for Kling 4.0, but SeeVid currently offers 720p and 1080p.
Is Kling 4.0 better than Kling 3.0? For longer clips, multiple characters and editing, yes. Kling 3.0 is still cheaper per second if a 15-second, 720p or 1080p clip is all you need.
How much does Kling 4.0 cost? It is billed per second with sound included — see the price table above. New accounts get free credits to try it.
Conclusion
Kling 4.0 is a big step for long-form AI video: 30 seconds in one pass, stereo sound, richer references and editing built into the model. If you need complete scenes rather than short clips — at a mid-range price — it is one of the strongest choices right now.