Why all three matter and when to use each
As AI image and design models mature, the question is no longer “What’s the best way to prompt?” but “What’s the right prompt format for this model and this task?”
JSON prompts, TOON prompts, and natural language prompts are all valid. They just solve different problems. Understanding where each one shines and where it breaks down is how you get better results with less friction, lower cost, and more creative control.
This guide breaks down how each prompt type works, which models they suit best, and how to move between them without losing style consistency.
1. JSON prompts
Maximum control, maximum consistency
JSON prompts are structured, explicit, and deterministic. Instead of describing what you want in flowing language, you define it in clearly separated fields such as style, lighting, materials, camera, mood, and constraints.
Why JSON prompts are powerful
JSON prompts excel when:
You need repeatable, consistent outputs
You are building style systems, not one-off images
You want prompts that behave more like configuration files than creative writing
This makes them especially effective with:
GPT-based image generation systems
Gemini-based models such as Nano Banana and Nano Banana Pro
These models are designed to interpret structured data cleanly. JSON gives them exactly what they want: unambiguous instructions with minimal interpretation drift.
Where JSON prompts struggle
JSON prompts are not universal:
High token usage
JSON is verbose. Every key, value, and nested object adds tokens, which increases cost.Poor compatibility with some diffusion-style models
Models like Midjourney and Seedream tend to perform better with descriptive natural language.Creatively rigid
JSON locks behaviour tightly. This is great for consistency, but bad for discovery and exploration.
In short, JSON prompts are best when you care about locking a look, not when you want to find one.
2. TOON prompts
Compressed structure with creative side effects
TOON prompts are a compressed evolution of JSON prompts. They aim to preserve structure while aggressively reducing token count by:
Removing redundant wording
Flattening hierarchy
Compressing descriptors into shorthand patterns
Why TOON prompts exist
TOON prompts solve a very real problem:
JSON prompts are expensive
Some models penalise verbosity
Token budgets matter at scale
TOON prompts are excellent when:
You want structured intent at a lower token cost
You are running large batch generations
You want faster iteration without fully abandoning structure
The trade-off: consistency vs discovery
Because TOON prompts compress meaning:
Some nuance is lost
Style definitions can blur
Outputs may drift slightly between generations
This is not always a downside.
TOON prompts are fantastic for exploration:
They often surface unexpected variations
They can reveal sub-styles hiding inside your original JSON
They are useful for stress-testing a style system
However, if your goal is pixel-level consistency, TOON prompts are not a perfect replacement for JSON. Think of them as a creative mutation layer, not a style lock.
3. Natural language prompts
The fastest way to think visually
Natural language prompting is how most people start with AI, and for good reason:
It is fast
It is intuitive
It works with every model
Why natural language is still king
Natural language prompts are ideal for:
Rapid ideation
Early-stage concepting
Mood exploration
Discovering new directions quickly
They allow you to think like a designer instead of an engineer.
Importantly, all models interpret natural language slightly differently:
Some prefer short, punchy descriptors
Others respond better to cinematic, descriptive language
Some prioritise adjectives, others prioritise nouns
Prompting is not portable by default. A prompt that works in one model often needs small adjustments in another.
Converting JSON to natural language
A powerful hybrid approach is:
Build your style in JSON
Convert that JSON into clean natural language
Use the converted prompt to style-lock models like:
Seedream
Seedance
Flux
Other diffusion-style systems
This gives you the consistency logic of JSON with the compatibility of natural language.
4. Midjourney: the outlier model
Natural language with a control layer
Midjourney sits in a category of its own.
At its core:
Midjourney prefers simple, clear natural language
Over-structuring usually hurts results
However, Midjourney adds an additional control system:
Moodboard references
Style reference codes (SREFs)
Image weighting and prompt codes
What works best in Midjourney
For Midjourney:
Keep prompts short and descriptive
Avoid JSON-style formatting entirely
Lock consistency using:
Reference images
SREF codes
Carefully curated moodboards
Midjourney rewards visual anchoring more than textual precision. The style lock happens through references, not through verbose instructions.
This is why JSON prompts tend to underperform in Midjourney, while well-crafted natural language plus strong references consistently outperform everything else.
Choosing the right prompt format
There is no universal winner. The best prompt format depends on what you are optimising for.
Goal | Best approach |
|---|---|
Maximum consistency | JSON prompts |
Lower token cost | TOON prompts |
Creative exploration | Natural language |
Batch experimentation | TOON prompts |
Style systems | JSON → Natural language |
Midjourney workflows | Natural language + references |
Final takeaway
Prompting is not about picking one format and committing forever.
JSON prompts give you control
TOON prompts give you efficiency and variation
Natural language gives you speed and creative freedom
The strongest workflows move between these formats, not against them.
If you treat prompts as living systems rather than static text blocks, you unlock far better results across every model you use.

