Kling 4.0 vs Kling 3.0: the spec differences in one dated table

Kling 4.0 changes six things you plan around: clip length (3 to 30 seconds), resolution and HDR, reference inputs, keyframes, audio, and prompt size. The table below sets Kling's own statements side by side, as read on 2026-10-03. Where a page did not state the Kling 3.0 value, the cell says so.

The table

Sources are the Kling 4.0 vs 3.0 page, the Kling 4.0 guide, and the multiple keyframes guide.

The HDR contradiction

One row needs care. The 4.0 guide says HDR is coming soon, while the comparison page lists 10-bit HDR. Treat HDR as unconfirmed until a delivered file shows it, and check the bit depth of a real output before you promise HDR to a client.

Mapping to a Sume request

The Sume video docs describe a different spread of limits. Most catalog models top out at 15 seconds, seedance-2.5 and wan-3.0 reach 30 seconds, and first and last frames go in frame_images while style or content references go in input_references. Those are the two fields a Kling 4.0 keyframe or Omni Reference plan would have to be translated into.

Which rows change a budget

Not every row in the table affects cost. Length does: a 30 second single shot replaces what used to be two clips and a join. Reference capacity does too: ten images and five videos in one request can replace several separate generations used to establish a character or a product.

Other rows affect risk more than cost. Keyframes reduce the number of times a story has to be stitched. HDR affects delivery, since a 10-bit file needs a pipeline that keeps 10 bits. Audio and languages affect whether you need a separate voice track. Rank the rows by what your project actually uses before you decide whether 4.0 is worth the switch.

• Length: fewer stitches, fewer visible joins.
• References: fewer setup generations for consistent characters.
• Keyframes: more control over a long shot.
• HDR: only matters if your delivery path preserves it.
• Audio and languages: may remove a separate voice step.

Check the catalog, not the announcement

The docs name no Kling 4.0 id on the pages read here. List the live catalog before writing code against it, since new ids appear in GET /v1/videos/models rather than in a blog post. The video generation docs describe the response fields to compare against this table.

• Compare supported_durations with the 3 to 30 second claim.
• Compare supported_resolutions and supported_aspect_ratios with the table.
• Read supported_input_references to see which reference types are accepted.
• Read generate_audio before assuming sound is on.