AgentSkillsCN

fal-model-guide

fal-model-guide

SKILL.md
--- frontmatter
name: fal-model-guide
description: Complete fal.ai model selection system. PROACTIVELY activate for: (1) Choosing image generation models (FLUX, SDXL), (2) Choosing video models (Kling, Sora, LTX), (3) Choosing audio models (Whisper, ElevenLabs), (4) Model quality vs speed comparison, (5) Cost optimization by model tier, (6) 3D generation models, (7) Model-specific parameters, (8) Development vs production model selection. Provides: Model comparison tables, decision trees, pricing tiers, performance benchmarks. Ensures optimal model selection for quality, speed, and cost.

Quick Reference

CategoryFast/CheapBalancedBest Quality
ImageFLUX SchnellFLUX.1 DevFLUX.2 Pro
VideoRunway TurboLTX-2 ProKling 2.6 Pro
Audio STTWhisper TurboWhisperWhisper Large v3
Audio TTSKokoroXTTSElevenLabs
FLUX ModelEndpointStepsUse Case
FLUX.2 Profal-ai/flux-2-pro28Production
FLUX.1 Devfal-ai/flux/dev28High quality
FLUX Schnellfal-ai/flux/schnell4Fast iteration
Video ModelDurationAudioSpeed
Kling 2.6 Pro5-10sYesSlow
LTX-2 Pro5sYesMedium
Runway Turbo5-10sNoFast

When to Use This Skill

Use for model selection decisions:

  • Comparing FLUX vs SDXL for image generation
  • Choosing video models by quality tier
  • Optimizing costs with appropriate model selection
  • Understanding model-specific parameters
  • Building production vs development pipelines

Related skills:

  • For text-to-image: see fal-text-to-image
  • For text-to-video: see fal-text-to-video
  • For audio models: see fal-audio

fal.ai Model Selection Guide

Comprehensive guide to selecting the right fal.ai model for your use case.

Image Generation Models

FLUX Family

ModelEndpointBest ForSpeedQualityCost
FLUX.2 [pro]fal-ai/flux-2-proProduction, best qualityMediumHighest$$$
FLUX.1 [dev]fal-ai/flux/devHigh quality, open-sourceMediumHigh$$
FLUX Schnellfal-ai/flux/schnellFast iterationFastGood$
FLUX LoRAfal-ai/flux-loraCustom trained stylesMediumHigh$$
FLUX Realismfal-ai/flux-realismPhotorealistic imagesMediumHigh$$

FLUX.2 Pro - Latest and best quality

typescript
const result = await fal.subscribe("fal-ai/flux-2-pro", {
  input: {
    prompt: "Professional product photo of a watch",
    image_size: "square_hd",
    num_inference_steps: 28,
    guidance_scale: 3.5
  }
});

FLUX.1 Dev - Best open-source option

typescript
const result = await fal.subscribe("fal-ai/flux/dev", {
  input: {
    prompt: "A serene mountain landscape",
    image_size: "landscape_16_9",
    num_inference_steps: 28
  }
});

FLUX Schnell - Fast 4-step generation

typescript
const result = await fal.subscribe("fal-ai/flux/schnell", {
  input: {
    prompt: "Quick concept sketch",
    num_inference_steps: 4  // Optimized for 4 steps
  }
});

Stable Diffusion Models

ModelEndpointBest For
Fast SDXLfal-ai/fast-sdxlSpeed, lower cost
SDXLfal-ai/stable-diffusion-xlClassic SDXL
SD 1.5fal-ai/stable-diffusion-v15Legacy compatibility
SDXL Turbofal-ai/sdxl-turboUltra-fast
typescript
// Fast SDXL - Good balance of speed and quality
const result = await fal.subscribe("fal-ai/fast-sdxl", {
  input: {
    prompt: "A colorful abstract painting",
    image_size: "square_hd",
    num_inference_steps: 25
  }
});

Specialized Image Models

ModelEndpointUse Case
Recraft V3fal-ai/recraft-v3Design assets, vectors
Ideogramfal-ai/ideogramText in images
Playground v2.5fal-ai/playground-v25Creative/artistic
Kandinsky 3fal-ai/kandinsky-3Russian model

Image-to-Image Models

ModelEndpointUse Case
FLUX i2ifal-ai/flux/dev/image-to-imageTransform images
FLUX Inpaintfal-ai/flux/dev/inpaintingEdit regions
FLUX ControlNetfal-ai/flux/dev/controlnetGuided generation
IP-Adapterfal-ai/ip-adapter-fluxStyle transfer
typescript
// Image-to-Image transformation
const result = await fal.subscribe("fal-ai/flux/dev/image-to-image", {
  input: {
    image_url: "https://example.com/photo.jpg",
    prompt: "Transform into watercolor painting style",
    strength: 0.75  // 0-1, how much to change
  }
});

// Inpainting (edit specific regions)
const result = await fal.subscribe("fal-ai/flux/dev/inpainting", {
  input: {
    image_url: "https://example.com/photo.jpg",
    mask_url: "https://example.com/mask.png",
    prompt: "A golden retriever"
  }
});

// ControlNet (structural guidance)
const result = await fal.subscribe("fal-ai/flux/dev/controlnet", {
  input: {
    prompt: "Modern house design",
    control_image_url: "https://example.com/edges.png",
    controlnet_conditioning_scale: 0.8
  }
});

Video Generation Models

Text-to-Video

ModelEndpointQualityDurationAudioBest For
Kling 2.6 Profal-ai/kling-video/v2.6/proHighest5-10sNativeCinematic
Sora 2fal-ai/soraHighest5-20sOptionalAdvanced
LTX-2 Profal-ai/ltx-video-2-proHigh5sYesFast HQ
Runway Gen-3fal-ai/runway/gen3/turboHigh5-10sNoFast
Lumafal-ai/luma-dream-machineGood5sNoCreative
CogVideoXfal-ai/cogvideoxGood6sNoOpen source

Kling 2.6 Pro - Best overall quality

typescript
const result = await fal.subscribe("fal-ai/kling-video/v2.6/pro", {
  input: {
    prompt: "A majestic eagle soaring over mountains at golden hour",
    duration: 5,
    aspect_ratio: "16:9",
    negative_prompt: "blurry, distorted",
    cfg_scale: 0.5
  }
});

LTX-2 Pro - Fast with audio

typescript
const result = await fal.subscribe("fal-ai/ltx-video-2-pro", {
  input: {
    prompt: "Ocean waves crashing on rocks",
    resolution: "720p",
    enable_audio: true
  }
});

Image-to-Video

ModelEndpointBest For
MiniMax Hailuofal-ai/minimax/video-01Image animation
Kling i2vfal-ai/kling-video/v2.6/pro/image-to-videoHQ animation
Luma i2vfal-ai/luma-dream-machineCreative
Runway i2vfal-ai/runway/gen3/turbo/image-to-videoFast
typescript
// Animate a still image
const result = await fal.subscribe("fal-ai/minimax/video-01", {
  input: {
    image_url: "https://example.com/portrait.jpg",
    prompt: "Person slowly turns head and smiles",
    prompt_optimizer: true
  }
});

Video-to-Video (Editing)

typescript
// Edit/transform existing video
const result = await fal.subscribe("fal-ai/kling-video/o1", {
  input: {
    video_url: "https://example.com/video.mp4",
    prompt: "Change to anime style"
  }
});

Audio Models

Speech-to-Text

ModelEndpointBest For
Whisperfal-ai/whisperAccurate transcription
Whisper Turbofal-ai/whisper-turboFast transcription
typescript
const result = await fal.subscribe("fal-ai/whisper", {
  input: {
    audio_url: "https://example.com/speech.mp3",
    task: "transcribe",  // or "translate"
    language: "en",
    chunk_level: "segment"
  }
});

console.log(result.text);
console.log(result.chunks);  // With timestamps

Text-to-Speech

ModelEndpointBest For
Elevenlabsfal-ai/elevenlabsPremium voices
F5-TTSfal-ai/f5-ttsVoice cloning
Kokorofal-ai/kokoroMulti-language
typescript
// Text-to-speech with Elevenlabs
const result = await fal.subscribe("fal-ai/elevenlabs", {
  input: {
    text: "Hello, welcome to our service.",
    voice_id: "voice_id_here"
  }
});

3D Generation Models

ModelEndpointUse Case
TripoSRfal-ai/triposrImage to 3D mesh
InstantMeshfal-ai/instantmeshFast 3D generation
Stable Zero123fal-ai/stable-zero123Novel view synthesis
typescript
// Generate 3D mesh from image
const result = await fal.subscribe("fal-ai/triposr", {
  input: {
    image_url: "https://example.com/object.jpg"
  }
});

console.log(result.model_mesh.url);  // GLB/OBJ file

Model Selection Decision Tree

code
What do you want to create?
├── Image
│   ├── From text only?
│   │   ├── Need best quality? → FLUX.2 Pro
│   │   ├── Need fast iteration? → FLUX Schnell
│   │   ├── Need open-source? → FLUX.1 Dev
│   │   └── Budget conscious? → Fast SDXL
│   ├── Transform existing image?
│   │   ├── Style transfer → FLUX i2i
│   │   ├── Edit specific region → FLUX Inpainting
│   │   └── Follow structure → FLUX ControlNet
│   └── Need text in image? → Ideogram
│
├── Video
│   ├── From text only?
│   │   ├── Need best quality? → Kling 2.6 Pro
│   │   ├── Need fast preview? → Runway Gen-3 Turbo
│   │   └── Need audio? → LTX-2 Pro or Kling
│   ├── Animate image? → MiniMax Hailuo
│   └── Edit video? → Kling O1
│
├── Audio
│   ├── Speech to text?
│   │   ├── Accurate → Whisper
│   │   └── Fast → Whisper Turbo
│   └── Text to speech? → Elevenlabs / F5-TTS
│
└── 3D
    └── Image to 3D? → TripoSR

Performance Comparison

Image Generation Speed

Model~Time (1024x1024)
FLUX Schnell1-2s
Fast SDXL2-3s
FLUX.1 Dev5-8s
FLUX.2 Pro8-12s

Video Generation Speed

Model~Time (5s video)
Runway Gen-3 Turbo30-60s
LTX-2 Pro60-90s
Kling 2.6 Pro120-180s

Cost Optimization Strategies

  1. Development Phase

    • Use FLUX Schnell for prompt iteration
    • Use Fast SDXL for quick tests
    • Use Runway Gen-3 Turbo for video previews
  2. Production Phase

    • FLUX.2 Pro for final images
    • Kling 2.6 Pro for final videos
  3. Batch Processing

    • Process during off-peak hours
    • Use appropriate image sizes (don't upscale unnecessarily)
    • Cache results by seed for reproducibility
  4. Resource Efficiency

    • Generate at target resolution (don't generate larger and downscale)
    • Use webhooks for high-volume (avoid polling overhead)
    • Implement client-side caching

Model-Specific Tips

FLUX Tips

  • Guidance scale 3-4 works best
  • 28 steps is optimal default
  • Schnell works best with 4 steps only
  • Detailed prompts produce better results

Video Tips

  • Include camera movement in prompts
  • Describe action/motion explicitly
  • Use negative prompts to avoid artifacts
  • Start with shorter duration for testing

Whisper Tips

  • Provide language hint for better accuracy
  • Use "translate" task for non-English to English
  • chunk_level="segment" gives timestamps

Explore More Models

Visit https://fal.ai/models for the complete catalog of 600+ models including:

  • Face restoration/enhancement
  • Background removal
  • Upscaling
  • Style transfer
  • OCR
  • Object detection
  • And many more specialized models