Tutorial7 min read

Negative Prompts for AI Video: What to Write and When

AI video negative prompts: VdoBloom has no negative-prompt field for video, so here is how to phrase exclusions in the main prompt.

By VdoBloom Team

Negative prompts are a list of things you do not want in the output, and on VdoBloom they work differently depending on whether you are generating video or images. Video generation has no negative-prompt field at all — there is nowhere to type one — so exclusions have to be phrased inside the main prompt. Image generation does have the field, but only on a few models, limited to 500 characters. For most AI video work, clear positive phrasing beats a negative list.

Updated October 2026.

What a negative prompt is meant to do

The idea comes from image generation, where a model can be given two prompts: one describing what you want, and one describing what you do not. The second is meant to steer the model away from a category of output — blur, extra fingers, text overlays, watermarks — without cluttering the first with exceptions. It works because the model has a direction to push against, rather than only a target to reach.

That indirection is also its weakness. A negative prompt cannot describe a place a thing should be removed from. Telling a model “no cars” when you want a street with no cars in it does not reliably empty the street; it sometimes produces a street with a car cropped at the edge, because the model has a strong prior that streets have cars. The negative tells it what to avoid naming, not what to un-draw.

Does VdoBloom have a negative prompt for video?

No. VdoBloom’s video generation interface does not expose a negative-prompt field on any video model, including Kling 3.0, Seedance, WAN, Veo and the rest. There is no box to type into and no per-model support to look for. If you are looking for a switch to turn on, there is not one.

That is not a gap unique to VdoBloom, and it reflects where the technology has moved. Current video models are trained to follow a described scene rather than to work around a list of prohibitions, and in practice a well-written positive prompt outperforms a positive prompt plus a negative one. The practical consequence is simple: on VdoBloom, everything you want excluded has to be described as part of the scene.

Where a negative prompt does exist on VdoBloom

Image generation is different. The image generation interface does include a negative prompt field, and it is capped at 500 characters, but it is only shown for models that support it. On VdoBloom that is exactly three models, all in the Qwen text-to-image line: Qwen2 Text-to-Image, Qwen Image 3.0 and Qwen Image 3.0 Pro. Select one of those and the field appears; select any other model and it does not.

Two limits are worth knowing before you plan around it. First, the image editing flow does not send a negative prompt at all, so adding one to an edit instruction has no effect. Second, even on the models that accept it, 500 characters is a short list — roughly a dozen short items. Treat it as a fine-tuning control, not a second script.

How to phrase exclusions in the main prompt

If you cannot say what you do not want, you describe what you do want instead, in enough detail that the unwanted thing has no room. Four techniques cover most cases.

1. Describe the space, not the absence

Instead of “no people in the background,” describe the background that is there: “an empty cobbled street at dawn, shuttered shopfronts on both sides, no pedestrians anywhere in frame.” Naming the surface and the buildings fills the frame with content, and the trailing clause works as emphasis rather than as an instruction to un-draw. The general rule: give the model something specific to render where the thing you do not want would otherwise be.

2. Name the positive alternative

“No text overlay” is weaker than “a clean frame with no text, no logos and no watermarks, the composition filling the full width.” Note that this still names text and logos — the trick is that each is paired with a positive statement about the frame. Where you can, replace the negative with its opposite: instead of “not blurry,” write “sharp focus across the whole subject, crisp detail on the foliage.”

3. Fix the cause, not the symptom

Most unwanted artefacts have a cause you can remove from the prompt. Extra hands appear when a scene is crowded, so reduce the number of people and specify what each is doing with their hands. Morphing faces appear when a face is small and turned away, so move the camera closer and describe the angle. Flickering appears when the shot has too much simultaneous motion, so choose one moving element and hold the rest. Changing the prompt to remove the cause is more reliable than adding a prohibition.

4. Cut, then add

When output keeps drifting toward something you do not want, the fastest fix is usually deletion. Long prompts that mention a subject three different ways give the model more chances to latch onto the wrong one. Write the shortest prompt that still produces the scene you mean, generate it, and add one clause at a time only when something is missing. This is the same discipline that makes a prompt reproducible.

Worked examples

What you want to excludeWeaker phrasingWhat to write instead
Extra people“no crowd, no people”“a single figure centred on an empty wet street, shopfronts either side, dawn light, nothing else in frame”
On-screen text“no text”“a clean frame with no lettering, signage or logos, the subject filling the full width”
Soft focus“not blurry”“sharp focus across the whole subject, crisp edge detail, deep depth of field”
Warped hands“no extra fingers”“the subject holds a single mug with both hands at chest height, hands fully visible and still”
Camera shake“no shaky camera”“a locked-off static shot on a tripod, no camera movement at all”
Wardrobe changes mid-clip“no outfit changes”“the subject wears the same navy coat throughout, standing still while only the steam moves”

When a prompt is rejected rather than misread

A separate problem is a prompt that is refused outright rather than generated badly. That is a content filter, not a negative-prompt failure, and adding exclusions will not help — the model has decided the request itself is out of bounds. Different models carry different content labels on VdoBloom, from strict to more permissive, and the label is shown before you generate, so the practical move is to check which tier you are on rather than reword the same request repeatedly. Kling prompt rejected: the fix and why Veo 3 refuses prompts cover the specific refusal behaviours, and AI video not following the prompt handles the case where the clip generates but ignores half of what you asked for.

A short negative list that actually earns its place

Where the field does exist — Qwen2 Text-to-Image, Qwen Image 3.0 and Qwen Image 3.0 Pro in image generation — keep it minimal and use it for genuine defects rather than scene content:

  • Artefact cleanup: blur, jpeg artefacts, low resolution, oversharpening halos.
  • Compositional defects: cropped subject, extra limbs, watermark, signature, border.
  • Style leakage: 3D render, cartoon, illustration — when you asked for a photograph.

Do not put scene content in it, do not repeat the main prompt’s subject, and do not exceed a dozen items. If the negative list is longer than the prompt, you have written a second prompt and the model has to reconcile two conflicting sets of instructions.

What this costs

Prompt wording is free to change; only generation costs credits. Kling 3.0 is priced per second across standard, pro and 4K tiers, from about 5.6 credits per second at the standard tier up to about 26.8 at 4K, with audio adding to the rate — and the cost is shown before every run, so iterating on your wording is cheap while your clips are short. Plans start at $15/month for 300 credits, or $10/month billed yearly at $0.05 per credit, and one-time packs start at $10.39 for 200 credits that never expire. India plans start at ₹199/month. New accounts start with 10 free credits and no card, and paid output is watermark-free with commercial rights. See the pricing page for the full list.

Frequently asked questions

Does VdoBloom support negative prompts for AI video?

No. No video model on VdoBloom exposes a negative-prompt field, so you cannot pass a negative list to Kling, Seedance, WAN or Veo. Everything you want excluded has to be phrased inside the main prompt.

Which image models support a negative prompt?

Exactly three: Qwen2 Text-to-Image, Qwen Image 3.0 and Qwen Image 3.0 Pro. The field appears when you select one of those, is capped at 500 characters, and is not sent at all in the image editing flow.

So are negative prompts useless for video?

Not useless, but the field-free equivalent is different: describe the scene you want so completely that the unwanted thing has no room. Naming what fills the space works better than naming what is absent. For current video models, positive phrasing is the more effective control.

Why does my clip still contain the thing I excluded?

Because naming something in a prompt, even to exclude it, can reinforce it — the model is drawn to what the prompt mentions. Remove the reference, describe what is there instead, and if the issue persists, fix the cause: fewer people, tighter framing, one moving element at a time.

Does a negative prompt fix a rejected generate?

No. A refusal is a content-filter decision, not a prompt-wording problem. Check the model’s content label before you generate and choose a tier that matches your material rather than rewording the same request repeatedly.

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