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LLM Chat Tab - Complete Guide
The LLM Chat Tab brings AI language model capabilities directly into ComfyUI, enabling you to generate, refine, and enhance prompts without leaving your workflow environment.
Table of Contents
- Overview
- Getting Started
- Supported Providers
- Text Generation
- Vision Features
- Advanced Options
- Conversation History
- Keyboard Shortcuts
- Tips & Best Practices
- Troubleshooting
Overview
Key Features
- Multi-Provider Support: LM Studio and Ollama with custom endpoint options
- Vision Capabilities: Upload and analyze images with vision-enabled models (drag-and-drop supported)
- Real-time Streaming: See responses generate in real-time with SSE
- Conversation History: Maintain context across multiple messages
- Preset System: Save and reuse complete LLM configurations (model, settings, system prompts)
- System Prompt Management: Create, save, and manage system prompts
- Advanced Options: Temperature, top-p, max tokens, presence/frequency penalties, keep-alive
- Cross-Tab Integration: Send responses to Prompt Builder or receive images from Gallery
- Keyboard Shortcuts: Ctrl+Enter to send, Escape to blur textareas
- Accessibility: Full keyboard navigation and screen reader support
When to Use
- Prompt Generation: Create detailed, creative prompts from simple descriptions
- Prompt Refinement: Enhance existing prompts with better structure and keywords
- Image Analysis: Describe images or get prompt suggestions from reference images
- Creative Assistance: Brainstorm ideas, variations, or themes
- Quality Control: Review and improve prompt quality before generation
Getting Started
Opening the LLM Tab
- Launch ComfyUI
- Look for the sidebar on the right side of the screen
- Click on the LLM or Chat tab icon
Basic Workflow
Basic Workflow
- Select a Provider: Choose LM Studio or Ollama
- Configure if needed: Set custom endpoints in settings (optional)
- Choose a Model: Select from available models for your provider
- Enter Your Prompt: Type your request in the text area
- Send: Click "Send" or press Ctrl+Enter
- Review Response: Watch the AI response stream in real-time
Supported Providers
Sage Utils currently supports local LLM providers for privacy, unlimited usage, and no API costs.
Local Providers
LM Studio
- Models: Any GGUF model you load in LM Studio
- Vision Support: ✅ (vision-capable models like LLaVA, BakLLaVA, MiniCPM-V)
- Setup:
- Download and install LM Studio
- Browse and download models from the built-in model browser
- Load a model in LM Studio
- Start the local server (Server tab → Start Server, default: http://localhost:1234)
- Select "lmstudio" from provider dropdown in Sage Utils
- Model will auto-detect
Advantages:
- Free and unlimited
- Complete privacy (runs locally)
- No internet required for generation
- Customizable models and parameters
- User-friendly GUI for model management
- Support for custom endpoints
Default Endpoint: http://localhost:1234/v1
Recommended Models:
- Text: Llama 3, Mistral, Qwen, Phi-3
- Vision: LLaVA 1.6, BakLLaVA, MiniCPM-V
Ollama
- Models: Any model available in Ollama library
- Vision Support: ✅ (llava, bakllava, minicpm-v models)
- Setup:
- Install Ollama
- Pull a model from terminal:
- Text:
ollama pull llama3.2orollama pull mistral - Vision:
ollama pull llavaorollama pull bakllava
- Text:
- Verify model is installed:
ollama list - Ensure Ollama service is running (runs automatically after install)
- Select "ollama" from provider dropdown in Sage Utils
- Enter exact model name (e.g., "llama3.2", "llava")
Advantages:
- Free and open source
- Easy model management via CLI
- Lightweight and efficient
- Active community and model library
- Automatic service management
- Simple installation
Default Endpoint: http://localhost:11434
Popular Models:
- Text Generation:
llama3.2- Fast and capablellama3.1- Larger, more powerfulmistral- Excellent performancemixtral- Mixture of expertsqwen2.5- Strong multilingual
- Vision:
llava- General vision understandingbakllava- Enhanced LLaVA variantminicpm-v- Efficient vision modelllava-phi3- Compact vision model
CLI Commands:
# List available models remotely
ollama list
# Pull a model
ollama pull llama3.2
# Run a model (test)
ollama run llama3.2
# Remove a model
ollama rm modelname
Custom Endpoints
Both providers support custom endpoint URLs for advanced configurations:
Use Cases:
- Docker containers running Ollama/LM Studio
- Remote Ollama instances on your network
- Custom ports (non-default)
- Network-accessible LM Studio instances
- Ollama running in WSL or VMs
Setup:
- Open Sage Utils settings
- Enable "Use Custom URL" for your provider
- Enter custom endpoint (e.g.,
http://192.168.1.100:11434) - Save settings
- Provider will use custom endpoint instead of default
Text Generation
Basic Usage
- Type your prompt in the main text area
- Click "Send" or press Ctrl+Enter
- Watch the response stream in real-time
- Copy response using the copy button
- Send to Prompt Builder to use in tag-based prompts
Example Prompts
Prompt Generation
Create a detailed prompt for a cyberpunk street scene at night
Prompt Refinement
Enhance this prompt with better details and artistic style:
"a girl in a park"
Creative Variations
Give me 5 variations of this theme:
"fantasy castle on a floating island"
System Prompts
System prompts set the behavior and personality of the AI. They're applied before every request.
To use:
- Click "Advanced Options" to expand
- Enter system prompt in the dedicated field
- System prompt persists across conversations
Example System Prompts:
You are an expert at creating detailed, artistic prompts for image generation.
Focus on visual details, lighting, composition, and artistic style.
You are a creative writing assistant specializing in fantasy and sci-fi themes.
Provide vivid descriptions with emphasis on mood and atmosphere.
Vision Features
Uploading Images
Three ways to add images:
-
File Upload:
- Click "Add Image" button
- Select up to 10 images
- Supported: JPEG, PNG, WEBP, GIF
- Max size: 10MB per image
-
Drag & Drop:
- Drag images from your file explorer
- Drop onto the preview area
- Visual feedback during drag
-
Paste:
- Copy image to clipboard
- Click in the LLM tab
- Press Ctrl+V
Image Validation
The system validates all uploads:
✅ Accepted Formats: JPEG, JPG, PNG, WEBP, GIF
✅ Maximum Size: 10MB per image
✅ Maximum Count: 10 images total
❌ Rejected:
- Unsupported formats (BMP, TIFF, SVG, etc.)
- Files over 10MB
- More than 10 images
Error Messages:
- "Unsupported format (BMP). Supported: JPEG, PNG, WEBP, GIF"
- "File too large (15.3MB). Maximum: 10MB"
- "Maximum 10 images allowed. Please remove some images first."
Vision Model Usage
Example Vision Prompts
Image Description:
Describe this image in detail, focusing on composition and artistic elements
Prompt Generation from Image:
Create a detailed prompt that would generate an image similar to this
Style Analysis:
Analyze the artistic style of this image and suggest similar styles
Multiple Image Comparison:
Compare these images and identify common themes or elements
Removing Images
- Click the × button on any image preview
- Click Clear All to remove all images
- Images are cleared when you start a new conversation
Advanced Options
Click "Advanced Options" to reveal additional settings:
Temperature (0.0 - 2.0)
Controls randomness and creativity:
- 0.0 - 0.3: Focused, deterministic, consistent
- 0.4 - 0.7: Balanced (recommended for most use cases)
- 0.8 - 1.2: Creative, varied, exploratory
- 1.3 - 2.0: Very random, experimental
Default: 0.7
Top P (0.0 - 1.0)
Controls diversity via nucleus sampling:
- 0.1 - 0.5: Conservative, safe choices
- 0.6 - 0.9: Balanced diversity
- 1.0: Maximum diversity
Default: 0.9
Max Tokens (1 - 4096+)
Maximum length of response:
- 100-500: Short, concise responses
- 500-1000: Medium responses
- 1000-2000: Detailed responses
- 2000+: Very detailed or multiple examples
Default: 2048
Presence Penalty (-2.0 - 2.0)
Encourages new topics:
- -2.0 - 0.0: Allows repetition
- 0.0: Neutral
- 0.1 - 1.0: Discourages repetition
- 1.0 - 2.0: Strongly avoids repetition
Default: 0.0
Frequency Penalty (-2.0 - 2.0)
Reduces word repetition:
- -2.0 - 0.0: Allows repeated words
- 0.0: Neutral
- 0.1 - 1.0: Discourages frequent words
- 1.0 - 2.0: Strongly avoids repetition
Default: 0.0
System Prompt
Sets AI behavior and personality. See System Prompts section.
Conversation History
How It Works
The LLM tab maintains conversation context automatically:
- Each message is stored (both user and AI)
- Context is maintained across multiple exchanges
- History is included in subsequent requests (when enabled)
- New conversation starts fresh
Managing Conversations
Start New Conversation:
- Click "New Conversation" button
- Clears all history
- Fresh context for new topic
Include/Exclude History:
- Toggle "Include History" in advanced options
- When enabled: AI remembers previous exchanges
- When disabled: Each message is independent
Max History Messages:
- Set how many previous messages to include
- Default: 10 messages
- Older messages are dropped automatically
Viewing History
Click "Conversation History" to see:
- All messages in current conversation
- User and assistant roles clearly labeled
- Timestamps for each exchange
- Copy individual messages
Best Practices
✅ Do:
- Start new conversation when changing topics
- Use history for iterative refinement
- Keep history enabled for context-dependent tasks
- Clear history when sensitive topics are discussed
❌ Don't:
- Let history grow too large (impacts token usage)
- Mix unrelated topics in one conversation
- Forget to start new conversation for fresh context
Keyboard Shortcuts
Text Input
- Ctrl+Enter: Send prompt
- Escape: Blur (unfocus) textarea
Navigation
- Tab: Move between fields
- Shift+Tab: Move backwards
Workflow
- Type prompt
- Press Ctrl+Enter to send
- Review response
- Press Escape to return to input
- Modify and send again
Tips & Best Practices
Prompt Writing
✅ Be Specific:
Good: "Create a detailed cyberpunk street scene with neon signs, rain-slicked
pavement, and crowds of people under umbrellas at night"
Avoid: "Make a cyberpunk scene"
✅ Use Context:
"Expand this basic prompt with artistic details, lighting, and composition:
[your basic prompt]"
✅ Request Structure:
"Format the prompt as: subject, setting, lighting, mood, style, quality tags"
✅ Iterate:
- Start broad, then refine
- Ask for variations
- Request specific improvements
Model Selection
For Prompt Generation:
- GPT-4o: Best balance of quality and speed
- Claude 3.5 Sonnet: Excellent creative writing
- Gemini 1.5 Pro: Great for detailed descriptions
- Local models (Llama 3.2): Free unlimited usage
For Vision Tasks:
- GPT-4o: Fast and accurate
- Claude 3 Opus: Best detail analysis
- LLaVA (local): Free, surprisingly good
Token Management
- Short prompts: 500-1000 max tokens
- Detailed responses: 1500-2500 max tokens
- Multiple examples: 3000-4000 max tokens
- Monitor usage to control costs (cloud providers)
Performance
- Use local models (LM Studio/Ollama) for unlimited free usage
- Enable streaming for better user experience
- Clear history periodically to reduce token usage
- Use appropriate max tokens to avoid waste
Troubleshooting
Common Issues
"Please select a model"
Problem: No model selected
Solution: Choose a model from the dropdown after selecting provider
"API Error: 401 Unauthorized"
Problem: Invalid or missing API key
Solution:
- Check API key is entered correctly
- Verify key is active on provider's platform
- Check for typos or extra spaces
"Connection failed" (Local providers)
Problem: LM Studio or Ollama not running
Solution:
- Ensure service is running
- Check correct port (LM Studio: 1234, Ollama: 11434)
- Verify firewall isn't blocking
"Model not found"
Problem: Specified model doesn't exist
Solution:
- Refresh model list
- Check spelling
- For Ollama:
ollama pull <model-name>first
"Image upload failed"
Problem: Invalid image file
Solution:
- Check format (JPEG, PNG, WEBP, GIF only)
- Verify size (under 10MB)
- Don't exceed 10 images total
Streaming stops mid-response
Problem: Connection interrupted
Solution:
- Click "Stop" then resend
- Check internet connection (cloud providers)
- Check local service still running
Response is too short/long
Problem: Max tokens setting
Solution: Adjust "Max Tokens" in Advanced Options
AI output is repetitive
Problem: Penalty settings too low
Solution: Increase presence/frequency penalty (0.5-1.0)
AI output is too random
Problem: Temperature too high
Solution: Decrease temperature (0.5-0.7)
Getting Help
If you encounter issues not covered here:
- Check GitHub Issues
- Review API Documentation for technical details
- Open a new issue with:
- Provider and model being used
- Error message (exact text)
- Steps to reproduce
- Screenshots if applicable
What's Next?
- Explore the Prompt Builder Guide
- Learn about Cross-Tab Integration
- Review API Documentation for custom integrations
- Check out Architecture for technical details
Happy prompting! 🎨✨