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Negative Prompting: Definition and Examples

Negative prompting is a technique that involves explicitly telling an AI model what it should not generate, thereby refining the results by excluding undesirable elements.

Full definition

Negative prompting is a prompt engineering method that relies on specifying elements to avoid in the output of an artificial intelligence model. Rather than just describing what you want (positive prompt), you add negative instructions to guide the model by telling it what to exclude. This approach is particularly common in image generation but also applies to language models.

In image generation (Stable Diffusion, Midjourney, DALL-E), negative prompting helps eliminate common visual artifacts like deformed hands, blurry faces, inconsistent backgrounds, or unwanted artistic styles. The model then assigns negative weight to these concepts during the generation process, reducing their likelihood in the final output.

For language models (LLMs), negative prompting takes the form of explicit instructions such as "do not include technical jargon," "avoid bullet points," or "do not fabricate information." These negative constraints help frame the response and avoid default model behaviors that do not meet user expectations.

The effectiveness of negative prompting is based on a fundamental principle: it is often easier to describe what you want to avoid than to exhaustively specify what you want. By combining positive and negative prompts, you achieve much finer control over the model's output, making it an essential technique for any prompt engineering practitioner.

Etymology

The term combines "negative" and "prompting" (giving instructions to an AI model). It emerged with the popularization of diffusion models for image generation in 2022, especially with Stable Diffusion, where a dedicated field for "negative prompts" was integrated into user interfaces.

Concrete examples

Image generation with Stable Diffusion — avoiding common visual defects

Realistic photo portrait of a woman, natural lighting, high quality | Negative: deformed hands, blurry, bad anatomy, low resolution, text, watermark

Content writing with an LLM — controlling tone and format

Explain how blockchain works. Do not use technical jargon. Do not use bullet points. Do not exceed 200 words. Avoid clichéd metaphors.

Code generation — preventing bad practices

Write a Python function for email validation. Do not use regex. Do not install an external dependency. Do not ignore edge cases like internationalized domains.

Practical usage

To use negative prompting effectively, start by identifying recurring defects in the model's outputs, then formulate explicit exclusions for each. With LLMs, integrate your negative constraints directly into the system prompt or at the end of the instruction. With image models, use the dedicated negative prompt field and adjust the CFG Scale parameter to control the intensity of the effect.

Related concepts

Positive promptClassifier-Free Guidance (CFG)Prompt weightingGeneration constraints

FAQ

Does negative prompting work with all AI models?
Most image generation models natively support negative prompting via a dedicated field. For LLMs like Claude or GPT, there is no separate field, but negative instructions phrased in natural language ("don't do…", "avoid…") are generally well understood and followed by the model.
Should I prioritize positive or negative instructions in a prompt?
Ideally, combine both. Positive instructions define the desired direction, while negative instructions eliminate unwanted results. As a rule of thumb, start by describing what you want, then add exclusions for specific issues you have observed in previous outputs.
Why does my negative prompt not seem to work?
Several possible reasons: the weight assigned to the negative prompt may be too low (adjust the CFG Scale for images), the terms used may be too vague, or the model may interpret your phrasing differently. Try to be more specific, use synonyms, and test different phrasings. For LLMs, rephrase your constraints in affirmative rather than negative terms if the model persists in ignoring your exclusions.

See also

How to use this prompt

  1. Copy the prompt with the button above.
  2. Paste it into ChatGPT, Claude or your favorite AI assistant.
  3. Replace the bracketed variables with your details, then refine the result.

About Prompt Guide

Prompt Guide is a free library of 2500+ ready-to-use prompts for ChatGPT, Claude and other AIs, with guides to learn prompting and tools to build and optimize your own prompts.

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