Kling 4.0 Flash API
kling-4.0-flashKling 4.0 Flash is the lighter tier of Kling 4.0, the newest video model in Kuaishou's Kling family, and like Kling 4.0 it generates sound together with the picture on every clip. On APIMODELS it is the model id kling-4.0-flash (kling-4-0-flash and kling-v4-flash also work) on the same endpoint as Kling 4.0, POST /v1/video/generations, with the same request shape, so moving between the two tiers means changing one string. What Flash keeps: text-to-video from a prompt alone; reference-to-video with up to 10 reference images in image_urls (@image_1 and on in the prompt), up to 5 reference videos in video_urls (@video_1 and on) and up to 7 named subjects in elements, called as @Name, where an image subject is 2 to 4 views with the main view first and a video subject is one single-shot clip of 3 to 8 seconds, with at most 3 video subjects; 15 materials per request in total; and keep_original_sound, which keeps the reference videos' own sound. What Flash narrows: output is 720p only; duration is any whole number of seconds from 3 to 20 (default 5); reference videos and video subjects together are at most 5 clips and must add up to 2 to 20 seconds; the keyframe route takes a first frame only (first_frame_url, mentioned as @first_frame), with no middle or last frames; there is no standalone voices list, so a character's voice is attached with elements[].voice_url; and the prompt is limited to 8,000 characters. aspect_ratio is auto, 16:9, 9:16, 1:1 or 21:9, and with a first frame the clip follows the image. Sound cannot be turned off; generate_audio: false returns a 400. Billing is per billed second. Without video input the rate is $0.094 per second, so 5 seconds cost $0.47, 10 seconds $0.94 and 20 seconds $1.88. With a reference video or video subject the rate is $0.063 per billed second, and the billed seconds are the output length × 2 when the input video is no longer than the output, or input + output when it is longer, with each input clip rounded up to whole seconds: a 10-second clip with a 5-second reference video is 20 billed seconds, $1.26. At 720p that is about 60% of the Kling 4.0 rate of $0.157 per second. Choose Kling 4.0 instead when you need 1080p, clips longer than 20 seconds, middle or last keyframes, or standalone voices. Failed generations are not charged.
Generate Video
Characters, products, outfits or places. Each one is @image_1, @image_2… in upload order.
MP4 / MOV / WebM, 2-20 seconds in total. Each one is @video_1, @video_2… Adding video changes the billing, see the estimate below.
Named subjects (elements, @Name), including a character voice through elements[].voice_url, are available through the API — see the Kling 4.0 Flash docs.
Kling 4.0 Flash outputs 720p. For 1080p, clips over 20 seconds, middle or last frames or standalone voices, use Kling 4.0.
auto leaves the framing to the model
Sound is generated with every clip and cannot be turned off.
$0.47 for this clip (720p, $0.094/s × 5s) · only successful generations are billed
Result
Generated video will appear here
Provide URLs and click Generate
$0.094 per Second
About 60% of the Kling 4.0 rate at 720p ($0.157 per second), on the same endpoint and request shape: switching tiers means changing one model string
3-20 Seconds at 720p, Sound Included
Any whole length from 3 to 20 seconds. Every clip comes with generated sound; keep_original_sound keeps the audio of your reference videos instead
References You @Mention
Up to 10 images, 5 videos and 7 named subjects, 15 materials in total, each pointed at in the prompt as @image_1, @video_1 or @Name
Voices Bound to Characters
Give a character subject its voice with elements[].voice_url. A standalone voices list is not available on Flash; that needs Kling 4.0
First-Frame Animation
Send first_frame_url and mention it as @first_frame; the clip follows the image's aspect ratio. Middle and last keyframes need Kling 4.0
Per-Second Pricing, Only on Success
$0.094/s, or $0.063 per billed second with a reference video (output × 2, or input + output). Failed generations are not charged
Kling 4.0 Flash API: Kling 4.0 video with sound at $0.094 per second
Kling 4.0 Flash is the lighter tier of Kuaishou's Kling 4.0: send a prompt, as many as 15 reference materials or one opening image, and get back a 3 to 20 second 720p clip whose sound is generated alongside the picture.
On APIMODELS the Kling 4.0 Flash API is the model id kling-4.0-flash on POST /v1/video/generations, the same endpoint and request shape as kling-4.0, billed at $0.094 per second, and a failed Kling 4.0 Flash generation is not charged.
- Model ID
kling-4.0-flash- Duration
- 3–20 s per take
- Resolution
- 720p
- References
- 10 images · 5 videos · 7 subjects
- Billing
- $0.094/s · $0.063/s with video
Kling 4.0 Flash at a glance
What the Kling 4.0 Flash tier keeps from Kling 4.0, and where it draws the line.
Sound on every clip
Always on
Kling 4.0 Flash generates audio together with the picture, and there is no silent mode. When you pass reference videos, keep_original_sound switches to the sound already in those clips.
keep_original_soundReferences by @mention
Up to 10 images and 5 videos
Name every input in the prompt as @image_1 or @video_1, numbered by array position, so the prompt can say what each picture and clip is for.
image_urlsvideo_urlsNamed subjects with voices
Up to 7 subjects
elements turns 2 to 4 views, or one single-shot clip of 3 to 8 seconds, into a subject you call as @Name. A character subject can carry its own voice_url.
elementsvoice_urlFirst-frame animation
One opening image
Send one image as the opening frame and mention it as @first_frame. The clip follows that image's aspect ratio.
first_frame_url3 to 20 seconds at 720p
Any whole second
duration is any whole number from 3 to 20. Every Kling 4.0 Flash clip is 720p, in auto, 16:9, 9:16, 1:1 or 21:9.
durationaspect_ratioThe Kling 4.0 request, unchanged
One string to switch
Kling 4.0 Flash shares the endpoint, the fields and the @mention syntax with kling-4.0, so a request moves between the two tiers by changing the model id.
kling-4.0-flashkling-4.0Two routes behind one Kling 4.0 Flash model id
The fields you send pick the route; a first frame and references never share a request.
Reference-to-video, including text-to-video
A prompt alone is text-to-video. Add images, videos and named subjects and Kling 4.0 Flash treats them as references, 15 materials at most.
image_urlsUp to 10 reference images, @image_1 onwardvideo_urlsUp to 5 clips; together with video subjects at most 5 clips and 2–20 s in totalelementsUp to 7 subjects, no more than 3 of them videos; voice_url gives a character a voicekeep_original_soundKeep the reference videos' own sound instead of new audio
Mention in the prompt@image_1 · @video_1 · @Name
First-frame-to-video
One image becomes the opening frame of the clip. Middle and last keyframes are outside Kling 4.0 Flash; they need Kling 4.0.
first_frame_urlThe opening frame; the clip keeps its aspect ratiopromptWhat happens after the first frame, up to 8,000 characters
Mention in the prompt@first_frame
Every @mention has to match an input in the same request. Because numbering follows array position, reordering image_urls changes which picture @image_2 means.
What Kling 4.0 Flash is used for
Five common jobs, each with what you send and what comes back.
Short social clips in batches
Input: one prompt per clip, with aspect_ratio 9:16, 1:1 or 16:9. Output: a 3 to 20 second 720p clip with sound for each request. A 10-second clip is $0.94, so 50 of them are $47.
promptaspect_ratioProduct videos from reference photos
Input: product photos in image_urls, or 2 to 4 views of the product as a named subject, plus a prompt that places it in a scene. Output: a 720p product clip in which Kling 4.0 Flash takes the product's look from your photos; reference images add nothing to the $0.094 per second rate.
image_urlselementsConcept and storyboard checks
Input: the prompt and references of each planned shot. Output: 720p drafts at $0.094 per second for choosing the take. The request moves to kling-4.0 unchanged, so the chosen shot can be rendered there at 1080p for the final version.
kling-4.0-flashkling-4.0Animating a first frame
Input: one image in first_frame_url and a prompt that says what happens next. Output: a clip that opens on that image and keeps its aspect ratio, 3 to 20 seconds long.
first_frame_urlReusing camera movement and pacing
Input: a reference clip in video_urls (2 to 20 seconds in total), mentioned as @video_1, with a prompt asking for the same camera movement and rhythm on new content. Output: a new clip that follows the reference, billed at $0.063 per billed second.
video_urls@video_1Not a fit for Kling 4.0 Flash: 1080p output, a single take longer than 20 seconds, middle or last keyframes, or standalone voices. Those jobs go to kling-4.0 with the same request format.
Kling 4.0 Flash pricing
$0.094 per second for most requests, and a different count once a video goes in.
$0.282
Smallest Kling 4.0 Flash request
3 seconds at $0.094 per second, sound included. The 20-second maximum without video input is $1.88.
| Request | Rate | Billed seconds |
|---|---|---|
| No video input (text, reference images, image subjects, first frame) | $0.094/s | Output length |
| Reference video or video subject, input no longer than output | $0.063/s | Output × 2 |
| Reference video or video subject, input longer than output | $0.063/s | Input + output |
5 s text-to-video
$0.47
5 × $0.094
10 s from reference images
$0.94
10 × $0.094; images are not billed separately
20 s from a first frame
$1.88
20 × $0.094, the longest Kling 4.0 Flash take
10 s with a 5 s reference video
$1.26
Input ≤ output: 10 × 2 = 20 billed s × $0.063
5 s with an 8 s reference video
$0.819
Input > output: 8 + 5 = 13 billed s × $0.063
The same 10 s on Kling 4.0
$1.57
10 × $0.157 at 720p, for comparison
Input clips count in whole seconds, rounded up per clip and measured when the task is created. Reference images, subject images and the first frame add nothing to the per-second rate, and a Kling 4.0 Flash generation that fails is not charged.
Kling 4.0 Flash request parameters
The fields both routes share, with the limits of the Kling 4.0 Flash tier.
model
kling-4.0-flash
The aliases kling-4-0-flash and kling-v4-flash reach the same model.
kling-4.0-flashprompt
Up to 8,000 characters
Required. Describe the action, the camera and the sound, and point at your inputs with @mentions.
promptduration
3–20 s, default 5
Whole seconds only. A single take past 20 seconds needs Kling 4.0, which goes to 30.
durationresolution
720p
The only output size of Kling 4.0 Flash: leave it out or send 720p. For 1080p, change the model id to kling-4.0.
resolutionaspect_ratio
auto · 16:9 · 9:16 · 1:1 · 21:9
Pick one of the five. With a first frame the clip follows the image instead.
aspect_ratiocallback_url
Optional webhook
We POST the finished Kling 4.0 Flash task to this URL. Without it, poll GET /v1/video/generations?task_id=.
callback_urlKling 4.0 Flash or Kling 4.0?
One model family and one request format; what changes is the price and the range.
720p is what you deliver
Social feeds, previews and in-app clips that ship at 720p: Kling 4.0 Flash charges $0.094 per second where Kling 4.0 charges $0.157.
Takes of 20 seconds or less
Any length from 3 to 20 seconds fits one Kling 4.0 Flash request, sound included.
Many variations of one shot
When you try several prompts, references or first frames per shot, every attempt is billed at $0.094 per second (Kling 4.0 is $0.157 at 720p).
Voices that belong to characters
If a voice_url on each speaking character covers your dialogue, Kling 4.0 Flash has what you need.
You need 1080p
Kling 4.0 renders 1080p at $0.235 per second; Kling 4.0 Flash stops at 720p.
One take longer than 20 seconds
Kling 4.0 runs up to 30 seconds per request.
Middle or last keyframes
Kling 4.0 can pin the start of a clip, up to 8 points in between and the end; Kling 4.0 Flash pins only the start.
Standalone voices
Kling 4.0 accepts a voices list of up to 3 named voice clips; on Kling 4.0 Flash a voice has to belong to a subject.
How to call the Kling 4.0 Flash API
From an API key to a finished clip in four steps.
Get an API key
Register on apimodels.app and generate a key from the console; the same key and USD balance work for Kling 4.0 Flash and the rest of the catalog.
Send the request
Send a POST to /v1/video/generations: set model to kling-4.0-flash, write the prompt, and add references or a first frame if you have them. A taskId comes back straight away.
Wait for the result
Poll GET /v1/video/generations?task_id= every 10 to 15 seconds, or pass callback_url and let us call you when the Kling 4.0 Flash task finishes.
Download the clip
resultUrls holds the finished video. Files are kept for 30 days, so copy them to your own storage.
curl -X POST https://api.apimodels.app/v1/video/generations \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "kling-4.0-flash",
"prompt": "The barista from @image_1 slides a latte across the counter and says: Your usual. Cups clink and the cafe hums in the background",
"image_urls": ["https://example.com/barista.jpg"],
"duration": 8,
"aspect_ratio": "9:16"
}'
# { "code": 200, "msg": "success", "data": { "taskId": "clxxx", "state": "pending" } }
curl "https://api.apimodels.app/v1/video/generations?task_id=TASK_ID" -H "Authorization: Bearer YOUR_API_KEY"
# { "code": 200, "data": { "state": "completed", "resultUrls": ["https://r2.apimodels.app/videos/clxxx.mp4"] } }Kling 4.0 Flash vs Kling 4.0 on APIMODELS
Both are Kuaishou's Kling 4.0 behind the same endpoint. Kling 4.0 Flash is the lighter tier: 720p only, takes of up to 20 seconds, a first frame but no middle or last keyframes, and no standalone voices, at $0.094 per second (Kling 4.0 is $0.157 at 720p).
One measured run on APIMODELS: a 3-second 720p text-to-video request on Kling 4.0 Flash returned its clip in about 66 seconds. That is a single run, not a speed guarantee.
| Kling 4.0 Flash | Kling 4.0 | |
|---|---|---|
| Model id | kling-4.0-flash | kling-4.0 |
| Price without video input | $0.094/s (720p) | $0.157/s (720p) · $0.235/s (1080p) |
| Price with reference video | $0.063 per billed second | $0.094 · $0.141 per billed second |
| Resolution | 720p | 720p / 1080p |
| Clip length | 3-20 s | 3-30 s |
| Reference images / videos / subjects | 10 / 5 / 7, 15 materials in total | 10 / 5 / 7, 15 materials in total |
| Reference video length | 2-20 s in total | 2-30 s per clip, at most 30 s combined |
| Frames | First frame only | First + up to 8 middle + last (10 in total) |
| Voices | elements[].voice_url only | voice_url plus up to 3 standalone voices |
| Prompt length | 8,000 characters | 10,000 characters |
| Audio | Always on | Always on |
| 10 s at 720p, no video input | $0.94 | $1.57 |
Sources
About Kling 4.0 Flash
Kling 4.0 Flash is a Video Generation API provided by Kling. Kling 4.0 Flash is the lighter tier of Kling 4.0, the newest video model in Kuaishou's Kling family, and like Kling 4.0 it generates sound together with the picture on every clip. On APIMODELS it is the model id kling-4.0-flash (kling-4-0-flash and kling-v4-flash also work) on the same endpoint as Kling 4.0, POST /v1/video/generations, with the same request shape, so moving between the two tiers means changing one string. What Flash keeps: text-to-video from a prompt alone; reference-to-video with up to 10 reference images in image_urls (@image_1 and on in the prompt), up to 5 reference videos in video_urls (@video_1 and on) and up to 7 named subjects in elements, called as @Name, where an image subject is 2 to 4 views with the main view first and a video subject is one single-shot clip of 3 to 8 seconds, with at most 3 video subjects; 15 materials per request in total; and keep_original_sound, which keeps the reference videos' own sound. What Flash narrows: output is 720p only; duration is any whole number of seconds from 3 to 20 (default 5); reference videos and video subjects together are at most 5 clips and must add up to 2 to 20 seconds; the keyframe route takes a first frame only (first_frame_url, mentioned as @first_frame), with no middle or last frames; there is no standalone voices list, so a character's voice is attached with elements[].voice_url; and the prompt is limited to 8,000 characters. aspect_ratio is auto, 16:9, 9:16, 1:1 or 21:9, and with a first frame the clip follows the image. Sound cannot be turned off; generate_audio: false returns a 400. Billing is per billed second. Without video input the rate is $0.094 per second, so 5 seconds cost $0.47, 10 seconds $0.94 and 20 seconds $1.88. With a reference video or video subject the rate is $0.063 per billed second, and the billed seconds are the output length × 2 when the input video is no longer than the output, or input + output when it is longer, with each input clip rounded up to whole seconds: a 10-second clip with a 5-second reference video is 20 billed seconds, $1.26. At 720p that is about 60% of the Kling 4.0 rate of $0.157 per second. Choose Kling 4.0 instead when you need 1080p, clips longer than 20 seconds, middle or last keyframes, or standalone voices. Failed generations are not charged. Through APIMODELS platform, you can access this model via a unified API with transparent pay-as-you-go pricing. Current pricing: 720p · per second: $0.094, 720p · 5s: $0.47, 720p · 10s: $0.94, 720p · 20s: $1.88, Reference video · 720p · per billed second: $0.063.
Related model: Kling 4.0 — the full tier, when you need 1080p, takes up to 30 seconds, middle and last keyframes or standalone voices — from $0.157/s
Related model: Kling V3 Omni — when you edit an existing clip and want to keep its original sound — from $0.088/s, $0.117/s with audio
Related model: Vidu Q4 — for 4K, or 540p from $0.042/s — 3-16 seconds, up to 15 reference images and 3 voice clips
Key Features
- $0.094 per Second -- About 60% of the Kling 4.0 rate at 720p ($0.157 per second), on the same endpoint and request shape: switching tiers means changing one model string
- 3-20 Seconds at 720p, Sound Included -- Any whole length from 3 to 20 seconds. Every clip comes with generated sound; keep_original_sound keeps the audio of your reference videos instead
- References You @Mention -- Up to 10 images, 5 videos and 7 named subjects, 15 materials in total, each pointed at in the prompt as @image_1, @video_1 or @Name
- Voices Bound to Characters -- Give a character subject its voice with elements[].voice_url. A standalone voices list is not available on Flash; that needs Kling 4.0
- First-Frame Animation -- Send first_frame_url and mention it as @first_frame; the clip follows the image's aspect ratio. Middle and last keyframes need Kling 4.0
- Per-Second Pricing, Only on Success -- $0.094/s, or $0.063 per billed second with a reference video (output × 2, or input + output). Failed generations are not charged
Use Cases
Marketing Videos
Quickly generate brand promotion videos for ad campaigns and social media marketing.
Social Media Content
Create compelling short-form video content for platforms like TikTok, Instagram, and YouTube.
Product Demos
Generate product feature demonstrations and tutorials to improve user conversion.
Educational Content
Produce course explanations, knowledge explainers, and training videos at an affordable price.
Why APIMODELS
- Unified API -- One API key to access all models, no need to register on multiple platforms
- Transparent Pricing -- Pay-as-you-go with per-call pricing published on every model page, ideal for indie developers and startups
- Instant Access -- Start right after signup; pay by card, PayPal, Alipay or USDT
- Full Documentation -- Detailed API docs with code examples in cURL, Python, and Node.js
Frequently Asked Questions
How to use Kling 4.0 Flash API?
Sign up at APIMODELS, get your API key, and call our unified API endpoint. We provide detailed API documentation with code examples in cURL, Python, and Node.js.
What is the difference between APIMODELS and the official Kling API?
APIMODELS offers the same Kling 4.0 Flash model through our aggregation platform. We provide a unified API interface so you do not need separate accounts for each provider - one API key to access all models.
What is Kling 4.0 Flash?
Kling 4.0 Flash is the lighter tier of Kling 4.0, the newest model in Kuaishou's Kling video family. It makes 3 to 20 second clips at 720p with sound generated in the same pass, from a prompt alone, from reference images, videos and named subjects that you call by @mention, or from a first frame. On apimodels.app it is the model id kling-4.0-flash (kling-4-0-flash and kling-v4-flash also work) on POST /v1/video/generations, the same endpoint and request shape as kling-4.0, at $0.094 per second. Typical uses: batches of short social clips, product videos from reference photos, concept and storyboard checks before a final render on Kling 4.0, first-frame animation, and reusing the camera movement and pacing of a reference video.
How much does Kling 4.0 Flash cost per second?
$0.094 per second without video input, which covers a prompt alone, reference images, image subjects and a first frame: 5 seconds cost $0.47, 10 seconds $0.94 and the 20-second maximum $1.88. With a reference video or a video subject the rate is $0.063 per billed second, and the billed seconds are output × 2 when the input video is no longer than the output, or input + output when it is longer, with each input clip rounded up to whole seconds. So a 10-second clip with a 5-second reference video is 20 billed seconds, $1.26, and a 5-second clip with an 8-second reference is 13 billed seconds, $0.819. Reference images and subject images are not billed separately, and failed generations are not charged.
What is the difference between Kling 4.0 Flash and Kling 4.0?
Price and range. Kling 4.0 Flash costs $0.094 per second, about 60% of the Kling 4.0 rate of $0.157 at 720p, and $0.063 instead of $0.094 per billed second with video input. Kling 4.0 adds 1080p ($0.235/s), clips up to 30 seconds, middle and last keyframes and a standalone voices list; Flash is 720p only, 3 to 20 seconds, first frame only, and takes a voice only through elements[].voice_url. The endpoint, the request fields and the @mention syntax are the same, so a request written for Flash runs on kling-4.0 by changing the model string. Pick Kling 4.0 when a shot needs any of those four things.
How long can a Kling 4.0 Flash video be, and in which resolution and aspect ratios?
duration takes any whole number of seconds from 3 to 20 (default 5), and every clip is 720p; for 1080p use kling-4.0. aspect_ratio is auto, 16:9, 9:16, 1:1 or 21:9, and when you send a first frame the clip follows the image's aspect ratio instead. Without video input the shortest clip, 3 seconds, costs $0.282 and the longest, 20 seconds, $1.88.
Does Kling 4.0 Flash generate audio, and can a character have its own voice?
Sound is generated with every clip and cannot be turned off; generate_audio: false returns a 400. When you pass reference videos, keep_original_sound keeps their own sound instead of new audio. To give a character a voice, add voice_url to that character's entry in elements and mention the character as @Name in the prompt. The standalone voices list that Kling 4.0 accepts is not supported on Flash, so a voice always belongs to a subject.
How many reference images, videos and subjects can one Kling 4.0 Flash request use?
Up to 15 materials in total: at most 10 reference images in image_urls, 5 reference videos in video_urls and 7 subjects in elements. An image subject is 2 to 4 images with the main view first; a video subject is one single-shot clip of 3 to 8 seconds, and no more than 3 subjects can be videos. Reference videos and video subjects together are limited to 5 clips that must add up to 2 to 20 seconds. In the prompt you point at them as @image_1, @video_1 and @Name, numbered by array position, and the prompt itself can run to 8,000 characters.
Can Kling 4.0 Flash start from a first frame or use keyframes?
It takes a first frame: send first_frame_url, mention it as @first_frame, and the clip keeps the image's aspect ratio. Middle keyframes (keyframe_urls) and a last frame (last_frame_url) are not available on Flash; they need Kling 4.0. A first frame cannot be combined with reference images, videos or subjects in the same request, and a first-frame request is billed at $0.094 per second.
How do I get an API key and call the Kling 4.0 Flash API?
Create an account at apimodels.app and generate an API key in the console; one key and one USD balance cover every model. Then POST to https://api.apimodels.app/v1/video/generations with the key as a Bearer token: curl -X POST https://api.apimodels.app/v1/video/generations -H "Authorization: Bearer YOUR_API_KEY" -H "Content-Type: application/json" -d '{"model": "kling-4.0-flash", "prompt": "The cyclist in @image_1 rides through a night market in the rain, neon reflecting on the wet street", "image_urls": ["https://example.com/cyclist.png"], "duration": 10}'. The response holds a taskId: poll GET /v1/video/generations?task_id= until the state is completed, or pass callback_url, then download the file within 30 days.
Can I try Kling 4.0 Flash for free?
Not entirely. Eligible new accounts get $0.10 of trial credit, but the smallest Kling 4.0 Flash request, 3 seconds, costs $0.282, so a first test needs a top-up; top-ups start at $10. The playground on this page shows the price before you click Generate, including the billed seconds when you add a reference video, and failed generations are not charged.
How does Kling 4.0 Flash compare with other models in the Video Generation category?
On APIMODELS, Kling 4.0 Flash runs alongside 60+ models on one API key and one balance, so choosing is about fit, not lock-in. It supports Text to Video, Reference to Video, First Frame to Video, Up to 10 Images + 5 Videos, Named Subjects, Native Audio, 720p, 3-20s, $0.094/s, and you can weigh it on price and capability against other models in the Video Generation category, then switch by changing a single model-name string — no new account or integration. Browse every model in that category with live pricing at apimodels.app/models.
What can Kling 4.0 Flash do?
Kling 4.0 Flash supports: Text to Video, Reference to Video, First Frame to Video, Up to 10 Images + 5 Videos, Named Subjects, Native Audio, 720p, 3-20s, $0.094/s. See the APIMODELS docs for full parameters and call examples.
Can I use the Kling 4.0 Flash API from any country, including mainland China?
Yes. APIMODELS does not restrict access by country: the site and the API answer requests from anywhere, and apimodels.app and api.apimodels.app are reachable directly from mainland China without a proxy. You call Kling 4.0 Flash with one APIMODELS key, so you do not need a separate account with the model's developer.
What payment methods are supported? Can I pay with PayPal or crypto?
Yes to both. You can top up with a card (Visa, Mastercard and others, through Stripe), PayPal, Alipay, or USDT on TRON (TRC20) or BNB Smart Chain (BEP20). Card, PayPal and Alipay top-ups are credited immediately; USDT is credited once the transfer confirms on-chain. Auto top-up is optional, and a $50 top-up adds a $1 bonus ($3 on a $100 top-up). The balance is in USD and billed per use, with no subscription.