Kling 2.1 is Kuaishou's flagship video generation model, released in 2025 as the successor to the original Kling that broke onto the global scene by ranking competitive with Sora on key benchmarks. The 2.1 release tightens motion physics, sharpens shot composition awareness, and pushes maximum resolution to 1080p — making it the practical default for short-form social, ad creatives, product demos, and concept art that needs to actually move. Polyfaced runs Kling 2.1 through the official Kuaishou-authorized infrastructure (via Kie), so you get the full feature set including image-to-video conditioning and native ratio control.
Why Kling 2.1 on Polyfaced
Native motion physics that pass the AI-tell test
Most AI video gives itself away in the first second — rubber faces, plasticy textures, motion that obeys nothing in particular. Kling 2.1 is one of the few models that actually moved past that. Watch the fog roll across this mountain valley: peaks reveal gradually, light shifts as the camera pulls back, and the air itself has weight. Run the same prompt twice and you get two cinematically coherent scenes, not two AI hallucinations. That's the bar Polyfaced ships against.
Image-to-video that actually preserves your subject
Text-to-video is great when you start from a blank canvas, but the moment you have a specific character or product in mind, identity drift kills the result. Switch to Image to Video mode in the studio, paste a starting frame, and Kling 2.1 animates it while keeping the subject locked. This golden retriever is the same dog in frame 1 and frame 120 — same coat, same gait, same eyes — because the model treats the input image as a constraint, not a suggestion.
1080p with prompt-aware shot composition
Most generators treat resolution as a knob and composition as luck. Kling 2.1 reads camera direction, framing, and depth of field from your prompt and renders them at 1080p without losing crispness. Tell it "close-up on a vintage espresso machine, warm cafe lighting, slow-motion steam" and you get exactly that — not a wider shot, not a softer light, not faster motion. It is the difference between "AI made me a video" and "AI made the video I described."
Iterate ad creatives in 60 seconds, not 60 hours
A 5-second prompt-to-video cycle costs 10 credits and finishes in 60–90 seconds. That means you can fire ten variations of the same product hero shot — different camera angles, different lighting, different motion direction — in the time a single afternoon shoot would take to set up. Teams use this for ad creative iteration, social-first variants, and pre-vis frames that need to actually move before you commit to a full production pipeline.
How to use
- 1
Pick text-to-video or image-to-video
Open the Video Generator panel and choose your starting point. Text-to-video describes the entire scene from scratch; image-to-video animates a starting frame you provide (paste an image URL, or upload from your dashboard once R2 upload is live in v1.1). Both modes share the same Kling 2.1 model — image-to-video tends to produce more controllable results when you already have a hero composition in mind.
- 2
Write a clear, specific prompt
The model rewards specificity. Describe the subject, the action, the camera movement, and the mood. Example: "A golden retriever runs across a flower field at sunset. The camera tracks alongside the dog in a slow dolly. Soft warm light, shallow depth of field, cinematic 35mm look." Keep prompts under 1000 characters — Kling 2.1 handles dense compositions but loses precision past that length.
- 3
Set ratio, resolution, and duration
Choose 16:9 for landscape (YouTube, ads), 9:16 for portrait (TikTok, Reels, Shorts), or 1:1 for social posts. Resolution toggles between 720p (cheaper, faster) and 1080p (production-grade, takes longer). Duration is 5s or 10s — 10s costs double credits but gives you the room for a real shot, not just a beat.
- 4
Generate and watch progress
Press Create Video. Polyfaced freezes the credit cost upfront, dispatches the job to Kuaishou, and streams progress back to your studio. Most 5-second runs at 720p land in 60-90 seconds; 10-second 1080p runs can take 2-3 minutes. The progress bar reflects the actual provider-reported progress when available, gradual estimation when not.
- 5
Download, share, or generate again
On success, your video appears in the right panel with autoplay and a Download button. The asset is permanently stored on Cloudflare R2 with a shareable URL — copy it, link it from a tweet, embed it in a presentation. Hit Generate Another to iterate, or open the dashboard history page to revisit and re-download previous runs anytime.
What people are creating
Short-form social content
Generate 9:16 vertical clips for TikTok, Reels, Shorts, or YouTube Shorts. The motion physics are clean enough to avoid the "AI plasticy" tell on most prompts, especially for landscape-led or product-focused scenes.
Ad creative iteration
Run 10 prompt variations of the same product hero shot in under 20 minutes. Pick the one that wins your team review, then iterate on lighting, ratio, or camera movement in a second pass — far faster than booking a shoot or commissioning motion graphics.
Concept art and pre-vis
Use image-to-video to bring storyboards and concept frames into motion. Filmmakers, game designers, and animators use Kling 2.1 to test whether a static composition reads correctly when the camera moves — before committing to a full production pipeline.
Product demos and explainer reels
Generate 10-second product motion clips (a watch rotating, a phone screen flipping, a logo morphing) for landing pages, App Store screenshots, and pitch decks. Kling 2.1 handles rigid-body motion notably well compared to peer models.
Model specifications
| Provider | Kuaishou (via Kie infrastructure) |
|---|---|
| Modalities | Text-to-video, Image-to-video |
| Max resolution | 1080p (1920×1080) |
| Max duration | 10 seconds per generation |
| Aspect ratios | 16:9, 9:16, 1:1 |
| Credit cost | 5s @ 720p = 10 credits · 5s @ 1080p = 20 credits · 10s doubles either |
| Typical generation time | 60-90s @ 720p, 2-3min @ 1080p |
| Prompt length cap | 1000 characters |
| Refund policy | Failed runs auto-refund credits to balance (FIFO ledger) |
FAQ
How does Kling 2.1 compare to Sora, Veo 3, and Seedance?
Kling 2.1 sits in the top tier across most independent benchmark sets for motion realism and prompt adherence — competitive with Sora 2 and Veo 3 on consumer-friendly scenes, ahead of most peers on character motion and product shots. Each model has stylistic fingerprints; we strongly recommend running the same prompt across providers when v2 lands the multi-model selector. For v1, Kling 2.1 is our pick because it has the strongest balance of quality, speed, and cost.
Can I generate video from an existing image?
Yes — switch to the Image to Video tab and paste an image URL. Kling 2.1 will animate the starting frame according to your motion prompt. This mode is significantly more controllable than text-to-video when you have a strong hero composition: the model preserves the subject identity and only generates the motion track. R2 upload (drag-and-drop from your computer) lands in v1.1; for now, host the image somewhere reachable and paste the URL.
What if my generation has the wrong subject or motion?
Iterate the prompt. Common fixes: (1) add specific subject anchors ("a golden retriever, not a cat"), (2) explicitly describe camera movement ("the camera dollies forward slowly"), (3) anchor the lighting ("soft warm sunset light"), (4) reduce simultaneous actions (one action per shot reads cleaner). If a generation fails entirely (content policy, upstream timeout), credits are auto-refunded — you can re-run safely.
Is the output watermarked?
Free plan outputs carry a small Polyfaced badge in the bottom corner — fine for personal preview but not for commercial use. Pro plan members ($29.9/mo) and Credit Pack buyers get fully clean, watermark-free outputs with a full commercial license — use them in client work, paid ads, products, or sale-distributed content. The watermark policy applies only to outputs generated on the Free plan; it does not retroactively apply to your Free outputs once you upgrade.
Where do my videos go after generation?
Storage rules differ by tier. Pro plan mirrors successful generations to our own Cloudflare R2 with a 90-day rolling retention window (10 GB per-user cap) and a durable share URL — open from your dashboard history any time within that window. Free and Credit Pack tiers use Kuaishou's 14-day CDN window; download to keep, or upgrade to Pro for long-term storage. Cancel Pro and we hold mirrored assets for 30 days with email reminders at 7d / 3d / 1d before purging — never a silent delete.
Can I use Kling 2.1 outputs commercially?
Pro plan members and Credit Pack buyers receive a full commercial license — use the videos in marketing, products, client work, paid social, or sale-distributed content. Free plan outputs are watermarked and personal-use only. Note: Kuaishou's underlying provider terms also apply (no extremist content, no impersonation, etc.) — content policy violations on the provider side may trigger a failed generation and an automatic refund.
Ready to generate your first Kling 2.1 video? Sign in with Google in one click to claim your 10 free credits. The free grant covers a full 5-second 720p run plus an extra short test — enough to evaluate whether Kling 2.1 fits your specific creative workflow before you commit to a Pro plan or Credit Pack. Cancel anytime, no annual lock, no hidden fees.