Veo 3.1 vs Kling 4.0 vs Runway Gen-4.5 (October 2026): Which AI Video Model Fits Your Job?

Short answer: pick Veo 3.1 for short, polished clips with native audio inside Google’s tools. Pick Kling 4.0 when you need long single takes (up to 30 seconds) or many keyframes and references. Pick Runway when you want one app or one API that runs its own Gen-4.5 model next to partner models such as Kling 3.0, Seedance and MiniMax. All of this comes from each vendor’s official pages, checked on October 18, 2026. We didn’t run our own tests.

How do Veo 3.1, Kling 4.0 and Runway Gen-4.5 compare?

The biggest differences are clip length, how much you can steer a shot, and where you can use the model.

	Google Veo 3.1	Kling 4.0	Runway Gen-4.5
Where you use it	Google Flow, Gemini API (Flow, Gemini API)	Kling’s creation workspace, plus Kling MCP and CLI (Kling 4.0 guide, Kuaishou)	Runway app (paid plans) and Runway API (changelog, Runway Dev)
Clip length per generation	4, 6 or 8 seconds	3–30 seconds, in 1-second steps	2–10 seconds through the API
Native audio	Yes, always on in the Gemini API	Yes (“high-quality audio”)	Runway’s API reference lists no audio parameter for gen4.5
Frames and keyframes	First frame, or first and last frame	First, last and middle keyframes, up to 10	First frame (Gen-4.5 API endpoint)
References	Up to 3 reference images (not on Lite)	Up to 15 reference assets: images, videos, voices, elements	Runway’s API reference lists no reference-image parameter for gen4.5
Resolution	720p, 1080p, 4K (4K not on Lite)	720p, 1080p, 4K; 10-bit HDR at 1080p and 4K per Kling’s spec table (official sources disagree; see below)	Text-to-video: 1280:720 or 720:1280; image-to-video: 6 ratios (1280:720, 720:1280, 1104:832, 960:960, 832:1104, 1584:672); 4K upscaling on paid app plans
API status	Preview model IDs in the Gemini API	Not yet; API covers Kling 3.0 family	Generally available in Runway’s API

Sources: Veo specs from the Gemini API Veo docs and Flow Help. Kling 4.0 specs from its user guide. Gen-4.5 durations from Runway’s API primer, which says gen4.5 accepts “any integer duration from 2 to 10”.

When should you pick Veo 3.1?

Pick Veo 3.1 when you want short clips with sound and you already use Google’s tools. Google’s API docs describe it as “a model for generating 8-second videos (720p, 1080p, or 4k) with natively generated audio” (Gemini API).

• Three tiers. In Google Flow you choose Veo 3.1 Lite, Fast or Quality. Reference images (“Ingredients”) work on Lite and Fast, not Quality. Extending a clip works only with Lite in Flow (Flow Help).
• Dialogue in the prompt. Google’s prompt guide tells you to put speech in quotes and to describe sound effects and ambience. The model then generates a matching soundtrack (Gemini API).
• Watermarking. Veo videos carry an invisible SynthID watermark (Gemini API).
• A note on Google’s own default. The Gemini API now recommends Gemini Omni Flash as its default video model, and Veo 3.1 for “scene extension, last-frame control, or integration with legacy pipelines” (Gemini API video overview).

Step-by-step access is in how to use Veo 3.1 in Gemini and Flow.

When should you pick Kling 4.0?

Pick Kling 4.0 when a shot has to run long or follow a plan beat by beat. Kuaishou says Kling 4.0 launched on October 15, 2026 with “native generation of up to 30 seconds in a single pass” (Kuaishou).

• Two ways in. Kling’s guide describes two entry points, Omni Reference and Keyframes, and says they “cannot be combined within a single generation task” (Kling 4.0 guide).
• Keyframes at any point. The Keyframes entry supports “first frames, last frames, start-and-last frames, and middle frames at any position in the timeline”, with up to 10 images.
• Lots of references. Omni Reference accepts up to 15 assets per task: up to 10 images, 5 videos (30 seconds in total), 7 elements and voice references.
• Long prompts. Prompts can run to 8,000 tokens.
• 4K and HDR: official sources disagree. The guide’s spec table lists 720p, 1080p and 4K with “10-bit HDR (1080p and 4K)”, but the same page’s highlights say “Supports 4K/1080p Resolution with 10-bit HDR output (coming soon)”, and Kuaishou’s release says Kling 4.0 “will also support 4K, 1080p and the 21:9 ultrawide format” (Kling 4.0 guide, Kuaishou). Check the options in the app before you plan a 4K or HDR delivery.
• No API yet. Kuaishou says Kling 4.0 “will soon be made available to enterprise customers and developers through API access”. The Kling API capability map currently lists Kling 3.0 Turbo, 3.0, 3.0 Omni, O1, 2.6 and 2.5 Turbo.

When should you pick Runway?

Pick Runway when you want several models behind one login or one API key. Runway’s model catalog describes “the best video, image, audio, and real-time models, available through one API”. It lists Runway’s Gen-4.5 and Aleph 2.0 alongside Google’s Gemini Omni Flash, Kling 3.0 and O3, Seedance, MiniMax and others (Runway Dev catalog).

• Gen-4.5 is for paid plans. Runway introduced Gen-4.5 on December 11, 2025 as “available for all paid plans”, and added first-frame image-to-video on January 21, 2026 (Runway changelog).
• Editing, not just generating. Aleph 2.0 is Runway’s “in-context video editing model with keyframe-guided control” (catalog).
• Last frames depend on the model. In Runway’s API, the gen4.5 image-to-video endpoint accepts only a first image position, and the reference lists no audio or reference-image parameters for gen4.5. Image-to-video does accept 6 aspect ratios: 1280:720, 720:1280, 1104:832, 960:960, 832:1104 and 1584:672; text-to-video accepts only 1280:720 and 720:1280. Partner models such as veo3.1 and several Kling models accept first and last (Runway API reference).
• Plugins. Runway now runs inside Adobe Premiere Pro, After Effects and DaVinci Resolve (changelog).

How do pricing and plans differ?

All three sell usage, but each counts it differently. We don’t list amounts; check the official pages.

Tier	Best for	Key differences	Official pricing
Google AI Plus / Pro / Ultra (Flow)	Using Veo 3.1 in Flow	Each plan adds monthly Flow credits on top of a daily allowance; Ultra gets the most credits and lower credit costs on Veo 3.1 Lite and Fast	Google AI plans, Flow credits
Gemini API paid tier	Veo 3.1 in your own app	Billed per second of video, higher for higher resolution; not available on the free tier	Gemini API pricing
Kling memberships	Kling 4.0 in the app	Paid memberships add monthly credits, watermark removal and unrestricted commercial use (Kling Terms of Paid Service 3.1.2)	Kling membership plans (prices shown after sign-in)
Runway Free / Standard / Pro / Max	Gen-4.5 and partner models in the app	Free is a one-time credit grant with a selection of models; paid plans unlock all models and remove watermarks	Runway pricing
Runway API credits	Gen-4.5 and partner models in your app	Credits bought per project in the developer portal; each model costs a set number of credits per second	Runway API pricing

Can you use the output commercially?

Generally yes on paid plans, but the terms differ. Read the full terms before you publish. This is a summary, not legal advice.

• Google: “Google won’t claim ownership over that content” (Google Terms).
• Runway: “The Company does not claim ownership of any of your Inputs or Outputs” and “does not restrict your commercial use of your Outputs” (Runway Terms of Use).
• Kling: for paid members, commercial use “is not restricted”, except for building competing products (Kling Terms of Paid Service 3.1.2). Members may also remove the Kling brand watermark; non-members must keep Kling branding on their output (Paid Terms 7.2). Without membership, its general terms bar commercial use without written permission (Kling Terms).

The full breakdown by tool is in Can you use AI videos commercially?

Which should you choose?

• Ad spots, social clips with dialogue: Veo 3.1.
• One continuous 15–30 second shot, or a planned sequence of beats: Kling 4.0.
• A team that also edits footage, or a product that needs several models behind one API: Runway.
• You need an API today for long clips: none of the three gives you Kling 4.0’s 30 seconds through an API yet. Compare options in AI video generation APIs compared.

For transitions between two exact shots, see first and last frame AI video. If you’re coming from Sora, start with Is Sora shut down?. Still images for your frames can come from an image model; see Midjourney and official image APIs. More tools by use case are in the AI video tools hub.