Veo 3.1 JSON Prompt Builder

What JSON prompting is — and why it beats prose for Veo

A JSON prompt describes your shot as named fields instead of one flowing paragraph: subject, scene, camera, lighting, audio, style, duration_seconds. Google Cloud’s official Veo prompting guidance endorses exactly this kind of structured, attribute-by-attribute prompt, and the community keeps rediscovering the same result: structured prompts land far more first-try successes than prose. Three reasons why:

• Nothing gets forgotten. Prose prompts routinely omit camera movement, audio, or duration because you simply did not think to mention them. A form with a field for each attribute forces the decision — and Veo fills unspecified attributes with whatever it likes, which is where most “that’s not what I asked for” results come from.
• Details stop bleeding into each other. In a paragraph, “dark” might attach to the jacket, the alley, or the mood. In JSON, "lighting" is unambiguous. This matters most for dialogue: a quoted line inside prose sometimes gets narrated or paraphrased, while a dialogue array with explicit speaker and line fields is delivered as speech.
• Iteration becomes surgical. When take one is 90% right, you change one field — swap the lens, adjust the lighting — and regenerate. With prose you end up rewriting the paragraph and accidentally changing three other things. This is the workflow paid tools like promptveo3.com sell; this page does it free in your browser.

The builder only emits fields you filled in, so the output stays compact, and it is generated with JSON.stringify — quoting and escaping are always correct, no matter what characters your dialogue contains.

Worked examples

Three complete prompts built with this exact structure. Copy them directly, or press Load into builder to drop one into the form above and start tweaking fields.

1. Cinematic shot — atmosphere and camera language

A single moody shot where camera and lighting carry the story. Note how the movement and lens are named precisely — Veo responds much better to real cinematography vocabulary (“slow dolly in”, “anamorphic”) than to vague words like “epic”.

2. Product shot — clean, controlled, ad-ready

For product work, keep the scene minimal and spend your budget on lighting and camera motion. A slow orbit plus studio lighting reads instantly as a commercial. No dialogue — let the music field set the tone instead.

3. Dialogue scene — two short sentences, no more

The dialogue budget is the most common failure point. This example stays inside the two-short-sentences rule for an 8-second clip, so the delivery is unhurried and the lip sync holds. If you load it and add a third sentence, watch the builder’s warning appear.

4. Ambient / ASMR shot — audio does the heavy lifting

Veo generates native audio, and prompts that specify it precisely stand out. Here the audio.ambient field is the star; the visuals stay simple so the soundscape reads clearly.

Go deeper: Veo guides on this site

• Veo 3 prompt list: ready-to-use 8-second video prompts — finished prompts for ads, cinematic clips, and social posts; the shot-type and audio vocabulary in this builder comes from that set.
• Funny Veo 3 prompts — comedy clips lean hardest on dialogue timing, which is exactly what the sentence lint above protects.
• Gemini Omni vs Veo vs Sora vs Runway — which AI video model to use for which job, and where Veo’s native audio gives it the edge.

More free tools

• Nano Banana prompt generator — the image-side equivalent of this builder, for Gemini’s Nano Banana model.
• Image fix prompt picker — repair blurry, plastic, or warped image output with paste-ready blocks.

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