Kling 3 audio on vs off for 100 fifteen-second SKU ads: $105 gap

Kling 3 Pro on Sume costs $0.14 per second with audio off and $0.21 with audio on, so a 15-second ad is $2.10 or $3.15. Across 100 SKUs the totals are $210 and $315, a $105 difference. Kling 3 takes 4 to 15 seconds in 720p or 1080p.

Price table

Per-second figures are the provider list rate times the 1.25 Sume margin that the docs describe, as of 2026-10-08. Read capabilities from GET /v1/video-router/models before you bill a batch, because rates and envelopes can change.

Decision

Audio on is worth it when the sound is part of the ad, such as a product click or a short voice. If you will add a voiceover or music in Timeline anyway, the generated audio is a cost you do not use. Voice-over synthesized separately is billed per character and music per generation, so compare the totals for your own clips first.

• Ratios: 16:9, 9:16 and 1:1; no 4:3 or 3:4.
• No reference_* fields on this model.
• Set generate_audio explicitly in the template.

Test

Run ten SKUs each way, listen, and pick. Ten SKUs at 15 s are $21.00 off and $31.50 on, and the sample tells you whether the extra $10.50 buys anything.

Beyond the clip price

Audio on adds $0.07 per second. Over a 15-second clip that is $1.05, and over 100 clips $105. A separate voiceover costs per character: 300 characters of narration is 0.3 x $0.0475 = $0.01425, so a separate voice track is far cheaper than Kling's generated audio when you only need speech.

If you want generated sound effects instead, audio on is the only route on this model.

• Voice by TTS: about $0.014 per 300 characters.
• Kling audio on: $1.05 extra per 15 s clip.
• Timeline audio mix: $0.01.

Before you scale

Kling 3 is also one of the models without reference fields, so it is a poor fit for jobs that need to keep a product's exact shape from several photos. Use it for image-to-video from one start frame when sound design is a factor, and use the reference-capable models for catalog consistency. Always set generate_audio explicitly rather than rely on a default.