Answer: Kling 4.0 costs 6 credits per second at 720p and 8.9 at 1080p, against 14 credits per second for Kling 3.0 and 8.5 for Kling 4.0 Flash at 720p. Kling 4.0 is the cheapest of the three and also the newest, with a 3–30 second duration range and generated audio.
The naming is not a ladder here. The newer model is the cheaper one, which is worth checking before you assume "3.0 → 4.0" means "premium → more premium".
The price ladder
| Model | 720p | 1080p | Duration | Notes |
|---|---|---|---|---|
| Kling 2.5 Pro | 8.4 credits/s | — | legacy range | older, cheapest in some lanes |
| Kling 2.6 | 11 | — | legacy range | |
| Kling 3.0 | 14 | — | legacy range | motion control variant is separate |
| Kling 4.0 | 6 | 8.9 | 3–30 s | native sound |
| Kling 4.0 Flash | 8.5 | — | check quote | 720p only in the current list |
| Kling O3 | 14 | — | scene-dependent | transformation route |
Read the 720p column twice: Kling 4.0 is less than half the per-second price of Kling 3.0, and it is the model with the thirty-second ceiling and the audio track.
What each tier is actually for
Kling 2.5 Pro — the legacy workhorse. If you have an existing pipeline pinned to 2.5, there is no reason to move for price alone; 8.4 credits a second for a five-second clip is 42 credits.
Kling 2.6 / 3.0 — the intermediate generations. At 11 and 14 credits a second they cost two to three times Kling 4.0 per second, without the longer duration range. Unless a specific reference mode only exists there, the newer tier wins on both price and control.
Kling 4.0 — the default. Six credits a second, 3–30 seconds, 720p or 1080p, and sound generated with the clip.
Kling 4.0 Flash — 8.5 credits a second at 720p. More per second than the model it is named after, so check the quote and the capability list before assuming "Flash" means cheaper. It exists for a different trade, not a cheaper one.
How to choose in one line each
- Need the cheapest usable take with sound? Kling 4.0 at 720p.
- Need 1080p? Kling 4.0 at 8.9/s — still cheaper than 3.0 at 720p.
- Need more than ten seconds? Only Kling 4.0 reaches thirty.
- Need a motion-control transfer? That is a separate Kling route, not a Kling 4.0 setting.
- Pinned to an older API shape? Stay where you are; the savings are real but a migration is not free.
The same shot, three ways
A ten-second vertical product shot with sound:
| Route | Credits | USD |
|---|---|---|
| Kling 3.0 · 720p | 140 | $1.40 |
| Kling 4.0 · 1080p | 89 | $0.89 |
| Kling 4.0 · 720p | 60 | $0.60 |
The middle row is the interesting one: 1080p on the newer model is cheaper than 720p on the older one, and it comes with a longer duration range if the shot needs it.
Where the comparison misleads
- Credits are not dollars. On a higher plan each credit costs less, so the same clip price moves. The ranking between tiers does not.
- Flash is not a discount tier. At 8.5 credits a second it costs more than 4.0 at the same resolution.
- Motion control is a separate route. Comparing its 20 credits a second to Kling 4.0's 6 is comparing different products.
FAQ
Is Kling 4.0 the newest and the cheapest? Yes on both counts among the tiers listed here.
Why is Flash more expensive than the model it is named after? Different trade-offs in whatever lane it serves; price it from the quote rather than from the name.
Do all these tiers support audio? No — audio support differs by model and mode; confirm before you budget a sound-led piece.
Do they all need a subscription? Kling 4.0 requires Starter or higher; check each model page for the others.
The current per-second table, including every Kling route, is on Callirra's Kling 4.0 page. If a shot needs the older model, the reason is usually a specific reference mode — worth naming in the commit message.