Kling 4.0 review, pricing and limits

Kling 4.0 was announced on 30 September 2026 with early access first and a wider rollout in October, alongside a 20-second Flash variant. It suits creators who want long continuous shots and reference-led editing, and it replaces Kling 3.0 for those jobs.

Kling 4.0 is a proprietary AI video model from Kuaishou Technology that generates clips of 3 to 30 seconds in a single pass, double the 15 seconds of Kling 3.0. It accepts up to 10 keyframes and 15 reference assets per task, and outputs two-channel stereo audio at 720p or 1080p.

Provider: Kuaishou Technology · Family: Kling

More about Kuaishou Technology on Hokai

Input modalities: text, image, video, audio · Output: video, audio

About Kling 4.0

Kling 4.0 is a video generation model from Kuaishou Technology, announced on 30 September 2026 and opened to early-access users before a wider rollout in October. It follows Kling 3.0 (February 2026) as the fourth major Kling generation and is the model behind the consumer studio and API of the Kling product. A faster, cheaper sibling, Kling 4.0 Flash, shipped alongside it for high-frequency work. The vendor does not publish a parameter count, an architecture paper or a training data summary, so those fields stay marked as not disclosed.

The headline change is clip length. Kling 4.0 generates 3 to 30 seconds in one pass, adjustable in 1-second steps with a 10-second default, where Kling 3.0 topped out at 15 seconds. Kling 4.0 Flash is limited to 3 to 20 seconds at 720p with standard dynamic range. Prompts can run to 8,000 tokens, and the model accepts up to 10 keyframe images to pin down character poses, scene changes and story beats inside a single long take.

Omni Reference is the second large upgrade. One task takes up to 15 reference assets: up to 10 images, 5 videos (30 seconds in total), 7 elements (including up to 3 video elements) and voice styles. Kuaishou describes three uses: recreating the pacing and shot composition of an existing clip with new products or characters, targeted edits to expressions, camera position or background while the rest of the scene stays stable, and keeping a character consistent across shots.

Audio and picture formats also changed. Output carries two-channel stereo audio with improved lip sync, and the vendor lists Chinese, English, Japanese, Korean, Spanish, Portuguese, German, French and Hindi, plus accents and dialects such as Cantonese, Sichuan, American, British and Indian English. Text, emoji and logos are meant to stay legible through camera moves. 21:9 is new alongside 16:9, 1:1 and 9:16. 10-bit HDR at 1080p and 4K is announced as coming soon, and the API price table lists 720P and 1080P only, so treat 4K and HDR as not yet generally available.

Quality is hard to rank this early. Standard language-model benchmarks such as SWE-bench, GPQA or MMLU-Pro do not apply to a video model, and no independent arena score for Kling 4.0 was readable on the day this page was written, so the benchmark fields are empty rather than estimated. The closest rivals are Seedance 2.5, Veo 3.1 and the open-weights Wan 3.0. Pick Kling 4.0 when you need long continuous shots or heavy reference control; pick a rival when you need self-hosting, a Western compliance paper trail or the lowest cost per second.

Access runs through two separate systems. The Kling app sells consumer plans paid in credits, and the Kling Open Platform sells prepaid API packages billed in units per second of video; the two pools do not mix. API billing counts input video seconds too, so editing a clip costs more than the output length suggests. Kuaishou publishes no zero-retention option and no SOC 2 or HIPAA statement on the pages read, so regulated teams should ask for terms before sending client footage. For a wider comparison of video tools see the best AI video generators guide, and for editing-led workflows look at Runway, CapCut, Pika and Higgsfield. Related reading: AI UGC video generators and turning photos into video. The vendor profile is Kuaishou Technology.

Pricing

Kling 4.0 is billed per second of video in units, not per token. The API price table (read 5 Nov 2026) charges Kling 4.0 1.0 unit a second in 720P and 1.5 in 1080P when no input video is supplied, and 0.6 and 0.9 with input video, where billed duration is input plus output seconds (or twice the output if the input is shorter). Kling 4.0 Flash costs 0.6 units per second at 720P. Package sizes run 3,250 units for $500, 13,135 for $2,000 and 53,640 for $8,000, so the unit price falls from about $0.154 to $0.149; packages last 180 days with no rollover and 20 concurrent jobs. No 4K price is listed. Consumer plans draw on a separate credit pool and do not give API access.

Key Features

• Native 30-Second Generation: Clip duration is set anywhere in that range in 1-second steps, so long takes need no stitching.
• Omni Reference: Combines up to 15 assets per task: 10 images, 5 videos totalling 30 seconds, 7 elements and voice styles.
• Multiple Keyframes: Accepts up to 10 keyframe images to control poses, scene changes and story beats.
• Stereo Audio and Lip Sync: Outputs two-channel stereo audio with improved lip sync across nine listed languages and several accents.
• Kling 4.0 Flash: A cheaper, faster variant for shorter clips at standard dynamic range, billed at a lower unit rate.

Pros

• Clip length doubles over Kling 3.0 in a single generation.
• Reference control covers mixed assets, including video and voice.
• Per-second API units are published openly with package sizes.

Cons

• 4K and HDR are announced but not yet priced or generally available.
• No independent arena score was readable at launch, so quality claims are vendor-reported.
• No self-hosting, retention terms or compliance certificates published.

Benchmarks

A benchmark is an exam, not the job. Scores transfer unevenly between tasks, so weigh the one closest to your workload and read every figure with its source.

Visit Kling 4.0 Official Page