比較一覧表
| 順位 | サービス名 | 料金 | 特徴 | 日本語対応 | プラン | 評価 |
|---|---|---|---|---|---|---|
| 1位 | Midjourney | From $10/month | Stunning artistic quality, best for creative visuals | Prompt only (English recommended) | 有料 | ★★★★☆ 4.7 |
| 2位 | DALL-E 3 (via ChatGPT) | Free tier / $20/month | Easiest to use, great text rendering in images | Full support | 有料 | ★★★★☆ 4.4 |
| 3位 | Stable Diffusion | Free (open source) | Maximum flexibility, runs locally, no content restrictions | Community models available | 有料 | ★★★★☆ 4.3 |
Midjourney Standard Plan
AI image generation has gone from a niche experiment to a mainstream creative tool. In 2026, anyone can create stunning visuals from a simple text description — no artistic training required.
But with so many tools available, choosing the right one can feel overwhelming, especially if you’re just getting started.
This guide breaks down the three most popular AI image generators — Midjourney, DALL-E, and Stable Diffusion — in plain language, so you can pick the best fit for your needs.
What Is AI Image Generation?
AI image generation uses machine learning models to create images from text descriptions (called prompts). You type something like “a cozy cabin in a snowy forest at sunset,” and the AI produces an original image matching that description.
These tools are trained on millions of images and learn to understand relationships between words and visual concepts. The result is surprisingly creative and often photorealistic output.
Who Is It For?
- Content creators who need blog thumbnails, social media graphics, or YouTube covers
- Small business owners who want marketing visuals without hiring a designer
- Students and hobbyists exploring digital art
- Professionals who need quick concept art or mockups
The Big Three: Overview
| Feature | Midjourney | DALL-E 3 | Stable Diffusion |
|---|---|---|---|
| Access | Web app | Via ChatGPT | Local install or cloud |
| Ease of Use | Medium | Very Easy | Advanced |
| Image Quality | Excellent | Very Good | Good to Excellent |
| Cost | From $10/month | Free tier available | Free (open source) |
| Customization | Moderate | Low | Very High |
| Best For | Artistic/creative work | Quick, easy generation | Full control & privacy |
Midjourney: The Artist’s Choice
What Is Midjourney?
Midjourney is a paid AI image generation service known for producing the most visually striking and artistic images of any AI tool. It excels at creating images with a distinctive aesthetic quality that often looks like professional digital art.
How It Works
- Go to midjourney.com and sign up
- Use the web-based editor to type your prompt
- Midjourney generates four image variations
- Select your favorite, upscale it, or request variations
Key Features
- Exceptional aesthetic quality — images look polished and professional out of the box
- Style control — use parameters like
--style,--chaos, and--stylizeto fine-tune output - Image blending — combine multiple reference images
- Pan and zoom — extend images beyond their original boundaries
- Fast generation — typically under 60 seconds per batch
Pricing
| Plan | Price | Fast GPU Hours | Features |
|---|---|---|---|
| Basic | $10/month | 3.3 hrs/month | Standard access |
| Standard | $30/month | 15 hrs/month | Unlimited relaxed mode |
| Pro | $60/month | 30 hrs/month | Stealth mode, faster |
| Mega | $120/month | 60 hrs/month | Maximum speed |
Pros and Cons
Pros:
- Best overall image quality and artistic style
- Active community for learning and inspiration
- Regular model updates with significant improvements
- Web interface is intuitive once you learn the basics
Cons:
- No free plan (free trials occasionally available)
- Requires learning prompt syntax for best results
- Less control over specific details compared to Stable Diffusion
- All generation happens in the cloud — no offline option
DALL-E 3: The Easiest Starting Point
What Is DALL-E?
DALL-E 3 is OpenAI’s image generation model, integrated directly into ChatGPT. It’s the most beginner-friendly option because you interact with it through natural conversation — just tell ChatGPT what you want, and it creates the image.
How It Works
- Open ChatGPT
- Type a description of the image you want in plain English
- ChatGPT automatically refines your prompt and generates the image
- Ask for modifications in natural language (“make the sky more dramatic” or “change it to a cartoon style”)
Key Features
- Conversational interface — no special syntax to learn
- Excellent text rendering — one of the few AI tools that can reliably put readable text inside images
- Automatic prompt enhancement — ChatGPT improves your description before sending it to DALL-E
- Edit mode — select areas of an image and ask for changes
- Integrated workflow — generate images while chatting about other topics
Pricing
DALL-E 3 is available through ChatGPT:
| Plan | Price | Image Generation |
|---|---|---|
| Free | $0 | Limited daily generations |
| Plus | $20/month | Generous daily limit |
| Pro | $200/month | Unlimited generations |
Pros and Cons
Pros:
- Lowest barrier to entry — just type what you want
- Free tier lets you try before paying
- Best-in-class text rendering within images
- Seamless integration with ChatGPT’s other capabilities
Cons:
- Less artistic flair compared to Midjourney
- Limited control over specific artistic parameters
- Daily generation limits on free and Plus plans
- Cannot run locally or offline
Stable Diffusion: The Power User’s Playground
What Is Stable Diffusion?
Stable Diffusion is an open-source AI image generation model that you can run on your own computer for free. It offers the most flexibility and customization of any AI image tool, but requires more technical knowledge to set up.
How It Works
- Install a user interface like AUTOMATIC1111 or ComfyUI on your computer
- Download the Stable Diffusion model (and optional fine-tuned models)
- Write prompts and adjust parameters like sampling steps, CFG scale, and seed values
- Generate images locally — no internet connection required
Key Features
- Completely free — no subscription, no usage limits
- Run locally — full privacy, no data sent to the cloud
- Massive model ecosystem — thousands of community fine-tuned models on Civitai and Hugging Face
- ControlNet — guide image generation with poses, depth maps, or edge detection
- Inpainting and outpainting — edit specific parts of images or extend them
- Training custom models — teach the AI to generate specific subjects or styles
System Requirements
| Component | Minimum | Recommended |
|---|---|---|
| GPU | NVIDIA 4GB VRAM | NVIDIA 8GB+ VRAM |
| RAM | 8GB | 16GB+ |
| Storage | 10GB | 50GB+ (for multiple models) |
| OS | Windows/Linux/macOS | Windows or Linux preferred |
Don’t have a powerful GPU? Cloud services like Google Colab, RunPod, and Paperspace let you rent GPU time. You can also use web-based interfaces like Clipdrop powered by Stable Diffusion.
Pros and Cons
Pros:
- Completely free and open source
- Maximum creative control and customization
- Huge community with thousands of models and extensions
- Full privacy — everything runs on your machine
- No content restrictions (depending on model)
Cons:
- Steepest learning curve of the three
- Requires a decent NVIDIA GPU for local use
- Setup can be intimidating for non-technical users
- Image quality depends heavily on model choice and settings
Get the Stable Diffusion Guide Book on Amazon
Head-to-Head Comparison
Image Quality
| Category | Winner | Notes |
|---|---|---|
| Photorealism | Midjourney | Most consistently realistic output |
| Artistic Style | Midjourney | Superior aesthetic quality |
| Text in Images | DALL-E 3 | Only tool that reliably renders readable text |
| Customization | Stable Diffusion | Thousands of specialized models |
| Consistency | DALL-E 3 | Most predictable results from simple prompts |
Ease of Use
- DALL-E 3 — Just type what you want in ChatGPT. Perfect for beginners.
- Midjourney — Intuitive web interface, but learning prompt parameters helps a lot.
- Stable Diffusion — Requires installation, configuration, and understanding of technical parameters.
Cost Comparison (Monthly)
| Usage Level | Midjourney | DALL-E 3 | Stable Diffusion |
|---|---|---|---|
| Casual (10-20 images) | $10 | Free | Free (if you have a GPU) |
| Regular (100+ images) | $30 | $20 | Free |
| Professional (500+ images) | $60 | $200 | Free (electricity cost only) |
Which Tool Should You Choose?
Choose Midjourney If:
- You want the best-looking images with minimal effort
- You’re creating content for social media, marketing, or creative projects
- You don’t mind paying $10-30/month for quality
- You enjoy being part of a creative community
Choose DALL-E 3 If:
- You’re a complete beginner and want the easiest experience
- You need text inside your images (logos, posters, memes)
- You already use ChatGPT and want image generation built in
- You want a free option to experiment with
Choose Stable Diffusion If:
- You’re technically inclined and enjoy tinkering
- You want full control over every aspect of generation
- Privacy matters — you don’t want images processed in the cloud
- You plan to generate a high volume of images without ongoing costs
- You want to train custom models on specific subjects or styles
Getting Started: Your First AI Image in 5 Minutes
The fastest way to try AI image generation right now:
- Open ChatGPT at chatgpt.com (free account works)
- Type a prompt like: “Create an image of a modern home office with plants, warm lighting, and a cat sleeping on the desk”
- Wait 15-30 seconds for your image to appear
- Iterate — ask ChatGPT to adjust colors, style, or composition
Once you’re comfortable with the basics, explore Midjourney for higher quality or Stable Diffusion for more control.
Prompt Writing Tips for Beginners
Good prompts make all the difference. Here’s a simple formula:
[Subject] + [Style] + [Details] + [Mood/Lighting]
Examples:
| Basic Prompt | Improved Prompt |
|---|---|
| ”a dog" | "a golden retriever puppy playing in autumn leaves, soft afternoon sunlight, shallow depth of field, professional photography" |
| "a city" | "a futuristic cyberpunk city at night, neon lights reflecting on wet streets, aerial view, cinematic lighting" |
| "a logo" | "a minimalist logo for a coffee shop called ‘Brew,’ clean vector design, earth tones, white background” |
Key Tips:
- Be specific — the more detail you provide, the better the result
- Mention art styles — “watercolor,” “oil painting,” “3D render,” “photorealistic”
- Describe lighting — “golden hour,” “studio lighting,” “neon glow,” “dramatic shadows”
- Specify composition — “close-up,” “aerial view,” “symmetrical,” “rule of thirds”
Conclusion
AI image generation is one of the most accessible and fun ways to experience AI technology firsthand. Whether you pick the artistic power of Midjourney, the simplicity of DALL-E 3, or the flexibility of Stable Diffusion, you’ll be creating impressive visuals in no time.
Our recommendation for beginners: Start with DALL-E 3 through ChatGPT (it’s free), then graduate to Midjourney when you want higher quality output. Consider Stable Diffusion once you’re comfortable and want maximum control.
The AI art world is evolving rapidly, and 2026 is the perfect time to jump in.
よくある質問(FAQ)
Do I need a powerful computer for AI image generation?
Not necessarily. Midjourney and DALL-E run in the cloud, so any device with a web browser works. Only Stable Diffusion benefits from a powerful local GPU (NVIDIA with 8GB+ VRAM), though cloud-hosted options like Google Colab exist.
Can I use AI-generated images commercially?
It depends on the tool. Midjourney's paid plans grant commercial usage rights. DALL-E images created through ChatGPT Plus are yours to use commercially. Stable Diffusion outputs are generally unrestricted, but check the specific model license.
Which AI image generator is best for absolute beginners?
DALL-E 3 via ChatGPT is the easiest starting point. You simply describe what you want in plain English — no special prompt syntax required. Midjourney produces more artistic results but has a slight learning curve.
Are AI-generated images copyrightable?
Copyright law around AI art is still evolving. In the US, purely AI-generated images without significant human creative input are generally not copyrightable. Adding substantial human modification may qualify for protection. Consult a legal professional for specific cases.
How do I write better prompts for AI image generation?
Be specific about subject, style, lighting, and composition. For example, instead of 'a cat,' try 'a fluffy orange tabby cat sitting on a windowsill, golden hour lighting, watercolor style.' Adding artistic references and technical details dramatically improves results.
Products & Services in This Article
Midjourney Standard Plan
ChatGPT Plus (DALL-E)
AUTOMATIC1111 Guide Book
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