Veo 3.1

Positioning Overview

Veo 3.1's text-to-video route is designed for developers who need to produce finished clips directly from a single line of text. It generates 4- to 8-second videos on demand at 720p to 4K in landscape or portrait orientation, with an optional native audio track that lets environmental sounds, dialogue, and sound effects described in the prompt be generated in sync with the visuals. You can call it by passing a prompt through the unified HiAPI.ai interface, making it suitable for scenarios that require rapid validation of visual ideas, such as short ads, vertical social media content, and storyboard previsualization.

Key Highlights

• Native audio-visual sync, no separate voiceover needed — when audio generation is enabled, the video comes with its own environmental sounds, dialogue, and sound effects, reducing post-production audio design and mixing work.
• Up to 4K resolution output per generation — resolution can be set to 720p, 1080p, or 4k, meeting different requirements from quick previews to high-quality deliverables.
• Switch between landscape and portrait as needed — aspect_ratio supports 16:9 and 9:16, so the same prompt can directly produce versions suited to feeds or vertical platforms.
• Controllable output with seed and negative prompts — use seed to reproduce generation results and negative_prompt to exclude unwanted elements, making it easy to keep a consistent style in batch production.

Capabilities

Direct text-to-short-video: enter a descriptive prompt (up to 20,000 characters) and directly get a 4-, 6-, or 8-second video clip without preparing any assets.

Native audio track generation: optionally generate native audio; describe environmental sounds, dialogue, or sound effects in the prompt and the finished video comes with synchronized sound, eliminating the separate voiceover process.

Resolution and aspect ratio control: output resolution covers 720p, 1080p, and 4k, and aspect ratio supports 16:9 and 9:16, so you can choose according to the delivery channel.

Reproducibility and negative constraints: a fixed seed allows the same result to be generated repeatedly, and negative_prompt is used to exclude unwanted visual elements, helping maintain consistency in batch output.

Use Cases

• Marketing teams quickly producing short ads — use a prompt describing product selling points to generate an 8-second clip with sound, directly usable for rapid validation of ad assets and first-cut editing.
• Social media operations creating vertical short videos — generate short videos in 9:16 aspect ratio for feeds or short-video platforms, skipping the landscape cropping step.
• Film and TV pre-production storyboard previsualization — turn storyboard descriptions into dynamic clips with sound effects for concept visualization and team communication, reducing trial-and-error costs before live-action shooting.
• Programmatic content production pipelines — developers can submit prompts in batches through the unified interface and connect the generated clips to their own content management systems or automated workflows.

Limitations and Selection Advice

A single generation is capped at 8 seconds; longer content requires multiple generations followed by stitching. Enabling audio or increasing resolution raises the cost per call, so it is recommended to choose specifications according to delivery requirements. This route is text-to-video and cannot upload reference images to maintain consistent character or product appearance; for that need, use the image-to-video route in the same family. If multi-shot continuity and long-form narrative are required, additional manual orchestration and consistency management are still necessary.