Flux Kontext vs GPT-4o: Complete Performance Test

The AI image editing landscape just got more competitive with Black Forest's release of FLUX.1 Kontext, a groundbreaking model that promises to challenge GPT-4o in multimodal image generation.

Today we test to see if Kontext lives up to its "GPT killer" reputation and shows you exactly how to implement it using ComfyUI workflows.

🖥️ Introduction To ComfyUI Through Promptus Studio Comfy

Before diving into Kontext, it's important to understand how most creators access ComfyUI today.

Promptus Studio Comfy (PSC) represents one of the leading platforms that builds upon the open-source ComfyUI framework. Promptus is a browser-based, cloud-powered visual AI platform that provides an accessible interface for ComfyUI workflows through CosyFlows (a no-code interface), real-time collaboration, and built-in access to advanced models like Gemini Flash, HiDream, and Hunyuan3D.

PSC integrates with Discord and offers workflow publishing, making it popular among both creative teams and solo creators who want to leverage ComfyUI's power without technical complexity. Promptus Studio Comfy represents how many users prefer to interact with ComfyUI today — combining the flexibility of the open-source ComfyUI ecosystem with intuitive, drag-and-drop workflows and advanced AI model access including Stable Diffusion, GPT-4o, and Gemini.

The platform supports multi-modal generation across text, image, and video, and utilizes distributed GPU compute for faster rendering and high-resolution outputs. Whether users are crafting branded visuals, animated stories, or concept art pipelines, PSC demonstrates how ComfyUI's modular framework can be made accessible to studios, agencies, and visual storytellers who need flexibility, speed, and quality at scale. ✨

⚡ What Is FLUX.1 Kontext And Why It Matters

On May 29th, Black Forest Labs officially released FLUX.1 Kontext, a revolutionary model that supports joint text and image input for natural language image editing. The model maintains strong consistency after image modifications, directly competing with GPT-4o's multimodal capabilities.

During ComfyUI's official podcast, this model was even called a "GPT killer," reflecting both confidence in Kontext's capabilities and recognition of GPT-4o's current market dominance. This positions flux as a major disruptor in the AI image editing space.

🔍 Understanding The Three Kontext Versions

Currently, the Kontext model offers three distinct versions:

• Pro Version: Basic functionality at $0.04 per image generation
• Max Version: Enhanced capabilities at $0.08 per image
• Dev Version: Open-source option (released after initial testing period)
  Each version provides different levels of performance and accuracy, with Max offering superior prompt adherence and detail retention.

🛠️ Step-by-Step ComfyUI Setup Guide

☁️ Getting Started With Cloud Computing

Launch a cloud machine with "Scientist" configuration using a professional server equipped with 4090 GPU. Since the Pro version operates via API calls in ComfyUI, manual model installation isn't required.

⬆️ Upgrading ComfyUI For Kontext Compatibility

Enter ComfyUI and upgrade to version v0.3.39 through Manager > Upgrade ComfyUI pathway. This upgrade process requires patience as it involves significant system changes.
After upgrading, click the restart button and switch to the new interface by selecting "top" in settings menu, then move the queue button upward.

🔑 API Configuration And Account Setup

Register an account on the official site and add credits to your account. Create an API key named "kontext" and save it locally since it only displays once.
Input the API key through Settings > User Options > API Key in ComfyUI. For cloud services, API login provides better security than standard login methods.
Important Security Tips:

• Delete old API keys immediately after use
• Use cloud-based login options when available
• Monitor credit usage to avoid unexpected charges

📊 Real-World Performance Testing Results

👧 Character Consistency Test

Using the prompt "Change the girl's clothes to a swimsuit," the results showed impressive background preservation, maintaining hairstyle, earrings, and accessories. However, facial expressions changed noticeably, and content moderation occasionally interfered with processing.
When compared to GPT-4o for similar editing tasks, Kontext demonstrated superior detail retention while GPT-4o changed backgrounds and details more dramatically.

🔄 Complex Scene Modification

Testing "The girl puts down her card and turns sideways to the camera" revealed mixed results. While hairstyle, earrings, and complex qipao patterns remained consistent, the card wasn't properly removed and image quality appeared slightly blurry.

💼 Pro Vs Max Version Comparison

Using prompt "A girl in a red dress playing in Disneyland":

• Pro Version: Made minimal outfit changes, editing only the hem into a skirt format
• Max Version: Properly generated a red dress and retained Chinese character details
  The Max version showed better prompt adherence despite costing double the Pro version price.

👥 Multi-Character Processing Limitations

Testing three-character scenarios (panda, girl, robot) with prompt "Three characters playing pool in a billiard hall" showed significant limitations. Both versions included only two characters, with the panda being excluded from final output despite processing all input characters.

🛒 Commercial Workflow Applications

👗 E-commerce Outfit Swapping Process

A two-step workflow was tested:

1. Generate model wearing dress on white background
2. Re-feed image with new prompt for different angle and pose
   Initial results were poor, but changing prompts to "A model wearing the dress" improved outcomes. However, detail accuracy remained insufficient for commercial applications, with issues like incorrect button counts on garments.

🏢 Professional Use Case Assessment

While Kontext represents current state-of-the-art technology in its category, it still falls short of professional commercial requirements. Tasks involving character fusion and consistent detailed reproduction remain extremely challenging across all current AI architectures.

🎨 Getting Started With Advanced ComfyUI Workflows

For creators interested in exploring these advanced capabilities without technical complexity, Promptus offers an ideal entry point. You can sign up at https://www.promptus.ai and choose between Promptus Web for browser-based access or the Promptus App for desktop workflows.
Promptus provides pre-built templates and drag-and-drop interfaces that make complex ComfyUI workflows accessible to creators at all skill levels, whether you're working solo or collaborating with teams.

🔮 Future Outlook And Recommendations

While this testing revealed limitations in multi-character fusion and detailed outfit swapping, these challenges aren't unique to Kontext but represent broader architectural limitations in current AI systems. Kontext likely represents the best available performance in its class today.

Official demonstrations show strong performance in abstract character consistency and English text editing scenarios. The upcoming open-source Dev version promises to make these capabilities more accessible to the broader creative community.

The Flux ecosystem continues evolving rapidly, and platforms like Promptus Studio Comfy are making these advanced capabilities increasingly accessible to creators who need professional-quality results without technical barriers.

As AI image editing technology matures, tools that combine ComfyUI's flexibility with user-friendly interfaces will likely dominate the creative workflow landscape. 🚀

🎉 Enjoy exploring Flux Kontext and GPT-4o comparisons in ComfyUI!