First-frame motion
Do not rewrite the frame; write how clay changes
The frame locks hands, bowl and light while the prompt owns rotation, pressure, droplets and protected structure.
Kling V2.1
Begin with one frame for credible motion, or lock the ending with two boundary images in Pro mode.
Boundary motion
When the image exists, the prompt owns change
Kling V2.1 is an image-to-video-only route in Flux Art. The frame supplies existing facts; the prompt describes action, force and camera without redefining subject, composition or material.
Image-to-video onlyStandard and ProPro boundary framesRealistic physicsNegative prompts
Pro boundary frames
Constrain the full path with two states
Base and summit images own the result; the prompt owns speed, rail path, shadows and deceleration.
Human and fabric physics
Make wind, fabric and balance explain each other
Define wind, scarf path and footwork to avoid intersections or unexplained imbalance.
Start and end states
Decide which input owns the information
The input route defines existing visual facts. The prompt should supply motion and change instead of competing with the source.
First-frame video
Add motion to one established image in Standard or Pro.
Pro start and end
Control the ending with two boundary states in Pro mode.
Path control
Where Kling V2.1 fits
Use it when a reliable first frame already exists and needs cost-effective product, human, material or environmental motion, optionally with a locked ending.
First-frame motion
Preserve subject, proportions, composition, light and material while describing only observable action and camera.
Pro boundary transition
Use two images to lock start and finish while the prompt owns path, speed, physics and continuity.
Object and material physics
Clay, fabric, plants and mechanisms need visible force and result to avoid unexplained deformation.
Standard versus Pro
Use Standard for quick validation and Pro for important motion quality or boundary-frame results.
Transition scripts
Kling V2.1 image-to-video briefs
Do not redescribe the image; spend prompt budget on action order, camera, force and protected details.
Wheel-thrown bowl
The first frame owns hands, bowl, wheel and window light. The wheel rotates steadily; hands stabilize the wall, then press once from base upward, creating continuous wet-clay rings as a few droplets move outward. Fixed close view; preserve fingers, rim, clay color and background tools.
Coastal funicular boundary
The first frame places the blue funicular at the hill base; the last has it at the top station. Fixed wide view centered on rails; it climbs steadily, crosses two tree shadows, slows and stops. Preserve carriage, rail count, coastline and golden sun direction.
Red scarf in wind
The first frame owns person, stone stairs and red scarf. A gust moves lower-left to upper-right; scarf leaves the palm, unfurls and passes before her shoulder. She steps and reaches as weight shifts. Slow lateral camera; preserve face, clothing, stairs and scarf length, with no fabric-body intersection.
Boundary check
How to use Kling V2.1 in Flux Art
Kuaishou debuted Kling 2.1 at the end of May 2025, describing broader improvements in motion, realistic physical simulation and semantic response with Standard and High Quality routes. Flux Art currently exposes first-frame video plus Pro start-and-end frames, both with negative prompts.
Create with Kling V2.1- Prepare an authoritative frameEnsure person, product, composition and light already work; add a second boundary image only when the ending matters.
- Describe only the changeWrite action, camera, force and stopping state in time order, then list what cannot change from the frame.
- Choose mode and reviewValidate direction in Standard; in Pro review physics, structure, continuity and end-frame alignment.
Source notes
Official sources and page information
Model capabilities are summarized from public Kling AI and Kuaishou materials. Available modes, parameters and pricing follow the current Flux Art workspace.
Published
Compare related Kling video models
- Kling V2.1 MasterUse stronger motion, physics and semantic response to push a high-quality single shot toward delivery.
- Kling V2.5 TurboPut multi-step action, credible physics, subtle expression and reference style into one shot.
- Kling V2 MasterUse a premium route to control action, semantics, cinematic light and explicit artistic style.
- Kling V1.6Control action, timing and camera from text, a first frame, a last frame or two boundary images.
Kling V2.1 FAQ
What is Kling V2.1?
Kling V2.1 is part of the model series Kuaishou introduced at the end of May 2025 with improvements in motion, realistic physical simulation and semantic response.
Is Kling V2.1 text-to-video available in Flux Art?
No. The current Flux Art configuration exposes image-to-video only: first-frame and Pro start-and-end-frame workflows.
Which modes are available for first-frame video?
First-frame generation currently supports Standard and Pro modes.
Which mode supports start and end frames?
The current start-and-end-frame route is Pro only.
Does Kling V2.1 support negative prompts?
Yes. Negative prompts are available for both current image-to-video workflows.
What should a first-frame prompt contain?
Describe only chronological action, camera motion, physical force and protected details; do not redescribe subjects or composition already present in the frame.
How should I use start and end frames?
Let the images define opening and closing states, then describe the path, speed, physical response and continuity required between them.
When should I choose Pro?
Use Standard to validate a direction quickly, and Pro when motion quality or an accurate boundary-frame result matters more.
Can results be used commercially?
Commercial use depends on current Flux Art and model-provider terms and your rights to prompts and reference media. Check the latest terms before client work.