Kling's image-to-video input has four rules: JPG or PNG, at least 300 by 300 pixels, at most 10 MB, and an aspect ratio between 1:2.5 and 2.5:1. That is how API resellers publish it; Magnific's Kling 3 docs put it as "minimum 300x300 pixels, maximum 10MB file size, aspect ratio between 1:2.5 and 2.5:1" (Magnific, Kling 3 API, checked 2026-09-28). On 8frame three of the four are handled for you. The one that is not is the minimum size.
TL;DR
- Under 300 x 300: refused. Nothing enlarges it for you. Upscale the image first.
- Over 10 MB: resized on 8frame, with one exception worth knowing: see Kling O3 below.
- Outside 1:2.5 to 2.5:1: adjusted on 8frame. A panorama or a very tall strip is brought into range instead of refused, which changes the framing.
- WebP, GIF and AVIF are accepted on 8frame as well as JPG and PNG.
- Kling rarely fails on 8frame. About one run in twenty failed in the 120 days to 2026-09-28, and every failed run was refunded automatically.
The rules, and what 8frame does with each
| Rule | Kling's limit | On 8frame |
|---|---|---|
| Minimum size | 300 x 300 | Refused below it |
| File size | 10 MB | Resized for you (see O3) |
| Aspect ratio | 1:2.5 to 2.5:1 | Adjusted into range |
| Format | JPG, PNG | PNG, JPG, WebP, GIF, AVIF accepted |
| Prompt | Up to 2,500 characters, every Kling version | |
| Video input (O1) | Up to 100 MB, MP4, MOV or WebM |
The 2,500-character prompt limit applies to v3 Standard and Pro, 2.6 Pro, O1 and O3. Other models' limits are in AI prompt length limits by model.
The failures we actually see
Kling is one of the more reliable models on the canvas. The few failures in our logs came from three causes:
- A content filter. "The content could not be processed because it contained material flagged by a content checker." Seen on Kling v3 Standard and older Kling runs. Change the reference image first, then the wording. More in refusal messages, decoded.
- Kling O3 and files over 10 MB. A few O3 image-to-video runs reached the provider with an image over its limit and failed with "File size exceeds the maximum allowed size of 10485760 bytes". Until that is fixed, keep O3 start images under 10 MB yourself.
- An aspect ratio O1 reference mode does not offer. Its error lists what it takes: "Input should be '16:9', '9:16' or '1:1'". Pick one of those three for the output.
Too small: the fix
Kling's 300 x 300 minimum is low, so this mostly bites on thumbnails, cropped logos and screenshots of small elements. Upscale the image on the canvas first (Clarity or Topaz), or regenerate it larger. Note that Veo 3.1 needs far more, 1280 by 720; the full comparison is in upload limits by model.
Choosing the Kling version
Credits on 8frame, a credit being about $0.01 at pack rate:
| Model | Clip | Credits |
|---|---|---|
| Kling 2.6 Pro | 5 s silent | 47 |
| Kling v3 Standard | 5 s silent | 57 |
| Kling v3 Standard | 5 s with audio | 86 |
| Kling 2.6 Pro | 5 s with audio | 95 |
| Kling v3 Pro | 5 s with audio | 114 |
| Kling v3 Standard | 10 s with audio | 171 |
Kling v3 runs from 3 to 15 seconds. For most image-to-video work the silent 2.6 Pro clip is the cheap test; move to v3 once the start image and motion are right. Details in Kling 3 pricing explained.
FAQ
What are Kling's image requirements for image to video? JPG or PNG, at least 300 x 300 pixels, up to 10 MB, aspect ratio between 1:2.5 and 2.5:1.
Why did Kling reject my image? On 8frame the usual reason is size: under 300 x 300 is refused. Larger files, other formats and extreme shapes are handled for you, except large files on Kling O3 for now.
What is Kling's maximum aspect ratio? 2.5:1 wide and 1:2.5 tall. On 8frame an image outside that range is adjusted rather than refused.
What is Kling's prompt limit? 2,500 characters on 8frame, for every Kling version.
Start images over 300 px and under 10 MB, and Kling rarely argues. The 8frame canvas is free and unlimited, and generation is paid from $19/month.