Kling 4.0 Flash vs Kling 4.0

Kling 4.0 Flash vs Kling 4.0 at a glance

Kling 4.0 Flash and Kling 4.0 are both Kling AI models in the Video Generation category, available through the EmpirioLabs API.

Key differences

• Kling 4.0 Flash is the newer release (Nov 4, 2026); Kling 4.0 was released on Oct 15, 2026.
• Kling 4.0 Flash lists the lower rate for Standard 720p (per second) and Video input 720p (per second of input plus output, at least twice the output).

Kling 4.0 Flash vs Kling 4.0: specs

Kling 4.0 Flash vs Kling 4.0: API pricing

Live rates from the EmpirioLabs catalog for both models. Each rate card always matches what the API charges.

Kling 4.0 Flash vs Kling 4.0: API parameters

Request parameters each model lists on EmpirioLabs, with the allowed values or range where one applies. A dash marks a parameter the model does not list.

Kling 4.0 Flash vs Kling 4.0: limits and notes

Kling 4.0 Flash

Generates 3 to 20 second clips at 24 fps in 720p, each with a native stereo audio track.

Inputs

• Text to video: prompt only.
• First frame (image): the video starts on this image and follows its aspect ratio.
• Reference images (reference_images): characters, objects, scenes or style to use. A first frame can be sent with them.
• Reference videos (reference_videos): motion, camera work or style to follow, 3 to 20 seconds each.
• Video edit (video): a video to edit, 3 to 20 seconds. The result keeps its length.
• Up to 10 images and 5 videos per request, with at most 20 seconds of video in total. In the prompt, refer to reference images as @image_1, @image_2 and to videos as @video_1, @video_2 (the video to edit first).
• Last and middle frames and 1080p are available on Kling 4.0.

In the Playground

One attached image is the first frame, and two or more are references. The first attached video is the one edited; any others are references.

Media limits

• Images: JPG or PNG, at least 300 px, aspect ratio between 2:5 and 5:2, up to 30 MB.
• Videos: MP4 or MOV, 3 to 20 seconds, 700 to 4553 px per side, 24 to 60 fps, up to 300 MB.

Billing

• Without a video input: billed per second of the generated clip.
• With a video input (a video to edit or a reference video): billed at the video input rate on twice the length of the generated clip, or on the input plus the output when the input is longer.

Kling 4.0

Generates 3 to 30 second clips at 24 fps in 720p or 1080p, each with a native stereo audio track.

Inputs

• Text to video: prompt only.
• Keyframes: a first frame (image), middle frames (middle_images) and a last frame (image_end). The video follows the first frame's aspect ratio.
• Reference images (reference_images): characters, objects, scenes or style to use.
• Reference videos (reference_videos): motion, camera work or style to follow, 3 to 30 seconds each.
• Video edit (video): a video to edit, 3 to 30 seconds. The result keeps its length and aspect ratio.
• Up to 10 images and 5 videos per request. In the prompt, refer to images as @image_1, @image_2 (first frame, middle frames, last frame, then references) and to videos as @video_1, @video_2 (the video to edit first).

In the Playground

One attached image is the first frame, two are the first and last frames, and three or more are references. The first attached video is the one edited; any others are references.

Media limits

• Images: JPG or PNG, at least 300 px, aspect ratio between 2:5 and 5:2, up to 30 MB.
• Videos: MP4 or MOV, 3 to 30 seconds, 700 to 4553 px per side, up to 300 MB.

Billing

• Without a video input: billed per second of the generated clip at the resolution you request.
• With a video input (a video to edit or a reference video): billed at the video input rate on twice the length of the generated clip, or on the input plus the output when the input is longer.

How to call Kling 4.0 Flash and Kling 4.0

Kling 4.0 Flash runs through POST /v1/videos/generations. The request returns a job_id right away; poll GET /v1/jobs/{job_id} until the job completes and read the output URLs from the result. Both models are called through the same endpoint. Set model to kling-4-0-flash or kling-4-0. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/videos/generations \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "kling-4-0-flash",
    "prompt": "Describe what you want Kling 4.0 Flash to generate."
  }'

Kling 4.0 Flash vs Kling 4.0: tests and guides

Prompt tests and comparison runs that cover both models.

Guides Kling 4.0 Flash vs Kling 4.0: Which Video API to Use Kling 4.0 Flash is the faster, lower-cost Kling 4.0: 720p clips up to 20 seconds. Kling 4.0 adds 1080p, clips up to 30...

Kling 4.0 Flash vs Kling 4.0: common questions

What is the difference between Kling 4.0 Flash and Kling 4.0?

Kling 4.0 Flash is the newer release (Nov 4, 2026); Kling 4.0 was released on Oct 15, 2026. Kling 4.0 Flash lists the lower rate for Standard 720p (per second) and Video input 720p (per second of input plus output, at least twice the output). The specs, rate cards, and parameters on this page come from the live EmpirioLabs catalog.

Which is newer, Kling 4.0 Flash or Kling 4.0?

Kling 4.0 Flash is the newer release (Nov 4, 2026); Kling 4.0 was released on Oct 15, 2026.

Which has the lower rate, Kling 4.0 Flash or Kling 4.0?

Kling 4.0 Flash lists the lower rate for Standard 720p (per second) and Video input 720p (per second of input plus output, at least twice the output). Both live rate cards are on this page and always match what the API charges.

Can I switch between Kling 4.0 Flash and Kling 4.0 without rebuilding my integration?

Yes. Both models use POST /v1/videos/generations with the same EmpirioLabs API key, so most integrations switch by changing the model value. Check the parameters table on this page first if you rely on a model-specific parameter.

Can I try Kling 4.0 Flash and Kling 4.0 in the browser before integrating?

Yes. Open each model in the EmpirioLabs playground and run the same prompt on both, with the parameters the API exposes.