Kling 4.0 vs Kling 3.0: What Changed and How to Choose

Kling 4.0 is now live on WaveSpeedAI, next to Kling 3.0 and the Kling O3 family. They are not a simple old-and-new pair: each is the better choice for different jobs, and this article compares them using what the live endpoints accept today.

Start with the Kling 4.0 API page or the Kling 4.0 collection, or try both in the Video Generator, where Kling 4.0 has Generate, Reference, Edit and Extend modes.

Quick answer

Pick Kling 4.0 for longer single takes (up to 30 seconds), for mixed image, video and audio references, and when you want to edit or extend footage on the same model.
Pick Kling 3.0 for native 4K, for multi-shot requests through multi_prompt, and for Turbo when you are iterating cheaply on prompts.
Keep the model id in configuration. Both use the same submit-and-poll pattern, so routing each shot type to the right model is a config edit.

Side-by-side: Kling 3.0 vs Kling 4.0 on WaveSpeedAI

Area	Kling 3.0 on WaveSpeedAI	Kling 4.0 on WaveSpeedAI
Tasks	Text-to-video, image-to-video, motion control; O3 adds reference-to-video and video editing	Text-to-video, image-to-video, reference-to-video, video edit and video extend, all on one model
Duration	3 to 15 seconds per generation	3 to 30 seconds per generation (whole seconds, default 5)
Resolution	Standard, Pro and native 4K tiers, plus Turbo	720p (default) or 1080p only; no 4K tier
Prompting	Up to six shots per request via `multi_prompt`, with automatic or custom shot splitting	One prompt per request; no `multi_prompt` parameter
References	Up to three Kling Elements on 3.0 image-to-video and O3; O3 reference-to-video takes up to seven reference images (four with a reference video)	Reference-to-video takes up to 10 images, 5 videos and 3 audios (15 files at most), cited in the prompt as @Image1, @Video1, @Audio1
Frames	First frame, optional end frame	First frame, optional `last_image`, and `keyframes` for in-between frames; up to 10 images in total
Edit and extend	Editing through Kling O3	Video edit (3 to 30 s input) and video extend on Kling 4.0 itself
Audio	Optional native sound on Standard, Pro and 4K	Synchronized stereo audio generated with the picture
Aspect ratios	16:9, 9:16, 1:1	16:9, 9:16, 1:1 and 21:9
Fast tier	Kling 3.0 Turbo Standard and Pro	None

Where Kling 3.0 is still the right pick

Native 4K

Kling 3.0 has native 4K tiers. Kling 4.0 on WaveSpeedAI stops at 1080p, so final renders that must be 4K belong on 3.0.

Multi-shot requests

Kling 3.0 accepts a multi_prompt array of up to six shots, and shot_type controls whether the model splits shots automatically (intelligence) or follows your breakdown (customize). For storyboarded ads and short-drama scenes this removes stitching work. Kling 4.0 takes one prompt per request. See the Kling 3.0 Pro text-to-video model page for the full parameter list.

Turbo for cheap iteration

Standard, Pro, 4K and Turbo on Kling 3.0 share the same inputs. Turbo is the natural place to iterate on prompts, and a prompt that works on Kling 3.0 Turbo Pro moves to Pro or 4K for the final render by changing the model path. Kling 4.0 has no Turbo tier.

Kling O3 and Elements

Kling O3 reference-to-video takes multiple reference images and an optional reference video, and Kling Elements, accepted by both Kling 3.0 image-to-video and O3, let you reuse the same character across clips.

Where Kling 4.0 is the right pick

Longer single takes

Kling 4.0 generates 3 to 30 seconds in one request, twice the 15-second ceiling of Kling 3.0. If a scene works as one continuous take, you no longer have to stitch segments.

Mixed references

Reference-to-video accepts up to 10 images, 5 videos and 3 audios in one request. Refer to them in the prompt as @Image1, @Video1 and @Audio1 in the order given. Set keep_original_sound to keep a reference video’s own sound instead of generating new audio. Aspect ratio defaults to auto, following the references.

Edit and extend on the same model

Video edit takes a 3 to 30 second video and a prompt describing the change, and keeps the scene, subject and motion. Video extend generates a new segment from the video’s last frame and returns the original and the new segment joined; an optional last_image gives it a target last frame.

In our quick tests, editing a 5-second coastal-road clip of a red vintage convertible into a snowy winter evening kept the same car, driver and motion, with snow on the road and cliffs, at 1280x720 with the audio kept. Extending a 5-second sailboat-at-sunrise clip by 5 seconds carried on the boat and bay, with the camera rising to reveal a harbor, and produced a 10-second clip with audio. These are single examples, not benchmarks.

Keyframes and wider framing

Image-to-video takes a first frame, an optional last frame and optional in-between keyframes in order, up to 10 images in total. Kling 4.0 also adds 21:9 for cinematic framing, alongside 16:9, 9:16 and 1:1. Text-to-video covers the prompt-only case.

How to test them against each other now

Both models are live, so the comparison takes an afternoon.

Freeze a prompt set. Pick 10 to 20 briefs from real work: a product close-up, a talking character, a fast camera move, a scene with text or hands, and a long continuous take.
Use the same settings. Fix duration, aspect ratio and, where possible, resolution (1080p works on both). Use identical inputs for each model, and keep the outputs.
Score what matters to you. For example: identity drift, hand and fabric artifacts, whether the camera move matches the prompt, and how many generations it takes to get an approved clip.
Compare cost per approved clip, not cost per generation. A cheaper model that needs more retries may not be cheaper.
Route by shot type, not all at once. Send long takes, mixed-reference and edit or extend work to 4.0, and 4K, multi-shot and Turbo drafts to 3.0.

Make the model choice a config change

Every Kling model on WaveSpeedAI uses the same pattern: submit a JSON body to the model path, receive a prediction ID, then poll for the result. Keep the model id in configuration and switching between Kling 3.0 and Kling 4.0 is a one-line edit. Remember that multi_prompt exists only on Kling 3.0, and Kling 4.0 durations can go up to 30 seconds, so read limits from the model schema rather than hard-coding them.

import os
import time
import requests

API_KEY = os.environ["WAVESPEED_API_KEY"]
BASE = "https://api.wavespeed.ai/api/v3"

# Read from configuration so choosing between the two models is a config change.
# Kling 3.0 Pro: kwaivgi/kling-v3.0-pro/text-to-video
# Kling 4.0:     kwaivgi/kling-v4.0/text-to-video
MODEL = os.environ.get("VIDEO_MODEL", "kwaivgi/kling-v4.0/text-to-video")

# Submit once. Do not retry this POST automatically: a retry after an ambiguous
# failure (timeout, 5xx) could create a second paid task.
resp = requests.post(
    f"{BASE}/{MODEL}",
    headers={"Authorization": f"Bearer {API_KEY}"},
    json={
        "prompt": "A chef plates a dessert in a dim restaurant kitchen, slow push-in, steam rising under a warm pendant light",
        "duration": 5,
        "aspect_ratio": "16:9",
    },
    timeout=60,
)
resp.raise_for_status()
prediction_id = resp.json()["data"]["id"]

# Poll until a terminal status.
TRANSIENT = {429, 500, 502, 503, 504}
failures = 0
while True:
    try:
        poll = requests.get(
            f"{BASE}/predictions/{prediction_id}/result",
            headers={"Authorization": f"Bearer {API_KEY}"},
            timeout=60,
        )
    except requests.RequestException:  # network error: back off and keep polling
        poll = None
    if poll is None or poll.status_code in TRANSIENT:
        failures += 1
        retry_after = poll.headers.get("Retry-After", "") if poll is not None else ""
        time.sleep(int(retry_after) if retry_after.isdigit() else min(2 ** failures, 60))
        continue
    if poll.status_code != 200:
        raise RuntimeError(f"task {prediction_id}: unexpected HTTP {poll.status_code}")
    failures = 0
    result = poll.json()["data"]
    if result["status"] == "completed":
        print(result["outputs"][0])
        break
    if result["status"] in {"failed", "cancelled", "timeout", "deleted"}:
        raise RuntimeError(f"task {prediction_id} {result['status']}: {result.get('error')}")
    time.sleep(2)

Pricing

Both models are billed per second of generated video, with no subscription.

Kling 4.0: at the time of writing, text-to-video, image-to-video and video extend cost $0.157 per second at 720p and $0.235 per second at 1080p, so a 5-second 720p clip is $0.785 and a 10-second 1080p clip is $2.35. Reference-to-video without a reference video uses the same rates. With reference videos, and for video edit, billing uses counted seconds (output length plus the longer of output length and total reference-video length, each capped at 30 seconds) at $0.094 per counted second at 720p and $0.141 at 1080p. Reference audios are not charged. Video extend charges only the new segment.
Kling 3.0: the rate is set by tier (Turbo, Standard, Pro, 4K) and whether native sound is enabled.

Current prices are on the Kling 4.0 API page and the Kling 3.0 API page.

Bottom line

Kling 4.0 and Kling 3.0 cover different strengths. Use 4.0 for long single takes, mixed image, video and audio references, and edit and extend on one model. Use 3.0 for native 4K, multi-shot multi_prompt requests and Turbo iteration. Keep the model id configurable, run your own frozen prompt set through both, and let cost per approved clip decide.

Related reading: Kling 4.0 Is Live on WaveSpeedAI: Models, Pricing, and How to Use Them. To try both models in the browser, open the WaveSpeedAI Video Generator.

FAQ

Is Kling 4.0 available on WaveSpeedAI?

Yes. Kling 4.0 has been live on WaveSpeedAI since October 2026 with five endpoints: text-to-video, image-to-video, reference-to-video, video edit and video extend. Each produces 3 to 30 second clips at 720p or 1080p with synchronized stereo audio.

Should I move from Kling 3.0 to Kling 4.0?

It depends on the job. Choose Kling 4.0 for single takes longer than 15 seconds, mixed image, video and audio references, or editing and extending clips on the same model. Stay on Kling 3.0 for native 4K, multi-shot requests with multi_prompt, and Turbo for cheap iteration.

Does Kling 4.0 support 4K or multi_prompt?

Not on WaveSpeedAI. Kling 4.0 endpoints offer 720p and 1080p only, and take one prompt per request with no multi_prompt parameter. Kling 3.0 provides native 4K tiers and up to six shots per request through multi_prompt.

How long can a Kling 4.0 clip be?

Kling 4.0 accepts 3 to 30 seconds per request, in whole seconds with a default of 5. Kling 3.0 accepts 3 to 15 seconds. Video extend generates a new segment of 3 to 30 seconds and returns it joined to the original.

How is Kling 4.0 priced compared with Kling 3.0?

Both are billed per second of generated video with no subscription. At the time of writing, Kling 4.0 text-to-video, image-to-video and video extend cost $0.157 per second at 720p and $0.235 per second at 1080p. Kling 3.0 rates depend on tier and sound. Check the Kling 4.0 and Kling 3.0 API pages for current prices.

Can I use the same code for both models?

Yes for the request pattern. Both use POST to api.wavespeed.ai/api/v3/ followed by the model id, return a prediction id, and are polled at the predictions result endpoint. Keep the model id in configuration, and note that parameters differ, for example multi_prompt exists only on Kling 3.0.

How do I compare Kling 3.0 and Kling 4.0 on my own prompts?

Freeze a prompt set, run it on both models with the same duration, aspect ratio and settings, and compare cost per approved clip. You can also open the WaveSpeedAI Video Generator and run the same brief through both models in the browser.