Kling AI image to video: settings that keep the subject

Kling's own pages say it keeps "recognizable characters, products, and visual styles" as images start to move, and give no numbers for how well. This page collects the limits Kling and its API partners document, then gives you a score sheet to measure drift on your own photos and a cost for a 60-clip test grid.

How do I turn an image into a video with Kling AI?

You upload one image in Kling's image-to-video mode, write a short motion prompt, pick a length and generate. Kling's feature page says you can upload "a photo, illustration, or product image."

1. Choose image-to-video and upload the picture.
2. Write one motion and one camera instruction.
3. Pick the length. Kling 3.0 accepts 3 to 15 seconds, and Kling 4.0 accepts 3 to 30 seconds (Kling, 2026-10-26).
4. Generate, then judge the clip against the source image.

Kling refunds the credits if a generation fails (Kling credits policy).

Which images keep the subject stable in Kling image to video?

The images that hold up best are sharp, large in frame and shown from the angle you want in motion. The hard limits come from Kling's partner documentation; the rest is advice to test.

Documented limits in ComfyUI's Kling nodes (checked 2026-10-26):

• At least 300x300 pixels.
• Start frame aspect ratio between 1:2.5 and 2.5:1.
• At most 10 MB.

These documents describe the kling-v2-5-turbo API model. Treat them as the safe floor for the Kling app too.

Checklist before you upload (our character photo checker scores a photo for you):

• The face or product fills a large part of the frame.
• Light on the subject is even, without hard shadows across the eyes or label.
• Nothing covers the face, such as a hand, hair or sunglasses.
• A product shows its main side, with the logo or label readable.
• A pet shows eyes and nose clearly, with the whole head in frame.
• The aspect ratio matches the clip you want (16:9, 9:16 or 1:1 in ComfyUI's nodes).

Skip images with several faces or a tiny subject. Kling has more to invent in those, and each invented detail is a chance to drift.

What should the motion prompt say?

A Kling image-to-video prompt should describe movement and camera only, in under 500 characters (see more prompt examples). The picture already supplies how the subject looks.

ComfyUI's Kling nodes require a non-empty prompt of at most 500 characters and allow a negative prompt of the same length. fal.ai's Kling v3 endpoint sets the default negative prompt to "blur, distort, and low quality".

Prompt shapes to test:

Avoid describing the face again ("blue eyes, freckles"). A second description gives the model another version to follow.

How do Kling start and end frames work?

A Kling start and end frame gives the clip a first image and a last image, and the model fills the movement between them. Kling says start and end frames "help guide a transition."

ComfyUI's start/end node documents these rules (checked 2026-10-26):

• Both images are required, each at least 300x300 and at most 10 MB.
• The start frame must have an aspect ratio between 1:2.5 and 2.5:1. The page states no aspect ratio limit for the end frame.
• Prompt up to 500 characters.

fal.ai's Kling v3 endpoint lists the end image as optional and does not say how it interacts with the start image.

Kling 4.0 adds up to 10 keyframe images to set poses, expressions and scene changes (Kling blog, 2026-09-30, early access at the time).

Best practice: use two photos of the same subject with the same framing, light and aspect ratio. A different background or outfit in the end frame asks the model to change the subject on the way there.

Which Kling settings affect how well the subject holds?

Four settings are documented: duration, cfg_scale, negative prompt and audio. Kling does not publish how each one changes identity, so the last column is your test list.

Sources: ComfyUI first-frame node, ComfyUI start/end node, fal.ai Kling v3.

How do I score identity drift in my own clips?

Score each clip against its source image on five yes/no checks and add the yeses. A clip scoring 5 kept the subject; 3 or lower drifted.

Pause at the first frame, the middle and the last frame, and compare each to the source. Two people scoring the same clip catches bias.

A small grid shows what moved the score. Use 10 images (4 people, 3 pets, 3 products), 3 setting combinations and 2 runs each. That is 60 clips.

What does a 60-clip test cost?

At the 5-second price ComfyUI shows for Kling's start/end node, 60 clips cost $21.00. The 10-second price of $0.70 doubles it to $42.00.

• 60 clips x $0.35 = $21.00 (5 s, kling-v2-5-turbo pro, ComfyUI price badge on 2026-10-26).
• 60 clips x $0.70 = $42.00 (10 s).

In Kling credits, the Kling VIDEO 3.0 credit guide lists 33 videos at 720p for the 660-credit Standard plan. That works out to 20 credits per clip. That is our division of the listed figures, not a rate Kling states for image-to-video. At that rate, 60 clips use 1,200 credits, which is more than one month of Standard and under half of the 3,000 credits on Pro.

See the Kling AI pricing guide for plan rates, and Is Kling AI free for what a free account can run. To price the grid on other models, use the AI video cost calculator. Run the grid in cheap batches. Stop when one setting clearly leads.

Is Kling AI image to video free?

Kling has a free Basic plan. Sources disagree on its credits, and Kling's plan guide lists it with no monthly credits; Is Kling AI free compares them. Your account balance shows what you can run today. Sites that offer "free Kling" image to video, such as Vidnoz, are third-party hosts that say only Kling has "a free tier with limited credits" (checked 2026-10-26).

Can I animate a photo of a real person with Kling?

Animate only photos you took or have written permission to use. A moving, talking clip of a real person can be taken for something they did.

Kling's community guidelines set the likeness and minors rules, so read them before you upload. The same applies to copyrighted characters and brand logos: the image owner's rights apply to the clip. For motion copied from a reference video, see Kling Motion Control.