Youtube Thumbnail

YouTube Thumbnail Design

Design click-worthy YouTube thumbnails that drive views using each::sense — the intelligent AI agent that automatically selects the best model for your request.

Quick Start

Requires an each::labs API key. Get one at eachlabs.ai.

Using curl

curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "Create a YouTube thumbnail for a tech review video. Split composition with a glowing smartphone on the left and an explosion of colorful app icons on the right, dark background, dramatic lighting, bold and vibrant, 16:9 aspect ratio."
      }
    ],
    "stream": false
  }'

Using Python (OpenAI SDK)

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_EACHLABS_API_KEY",
    base_url="https://eachsense-agent.core.eachlabs.run/v1"
)

response = client.chat.completions.create(
    model="eachsense/beta",
    messages=[{
        "role": "user",
        "content": "Create a YouTube thumbnail for a tech review video. Split composition with a glowing smartphone on the left and an explosion of colorful app icons on the right, dark background, dramatic lighting, bold and vibrant, 16:9 aspect ratio."
    }]
)

print(response.choices[0].message.content)

With Reference Image

Provide a frame from your video or a style reference for consistent channel branding:

curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": [
              {"type": "text", "text": "Create a YouTube thumbnail using this video frame as a base. Add dramatic lighting, increase contrast, make the background darker and more cinematic, 16:9 aspect ratio."},
              {"type": "image_url", "image_url": {"url": "https://example.com/video-frame.jpg"}}
            ]
          }
    ],
    "stream": false
  }'

Images are sent inside messages using the OpenAI multimodal content format. Maximum 4 images per request.

Streaming

Set "stream": true for real-time SSE responses, or "stream": false for complete result in a single response. Streaming is useful for showing progress in UIs; non-streaming is simpler for scripts and automation.

Thumbnail Anatomy

Prompt Engineering Tips

Keywords That Work

YouTube thumbnail, dramatic lighting, bold contrast, vibrant saturated colors,
cinematic composition, dark background, eye-catching, 16:9 aspect ratio,
high impact visual, attention-grabbing, split composition, spotlight effect

Keywords to Avoid

subtle and muted — thumbnails need to pop at small sizes
lots of small details — lost in YouTube's grid view
text-heavy — add text in post-production for reliability
realistic documentary style — too bland for thumbnail grid

Prompt Structure

YouTube thumbnail for [topic], [subject description], [background/lighting], [color scheme], [composition notes], 16:9 aspect ratio

Examples

Cooking Channel Thumbnail

curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "Create a YouTube thumbnail for a cooking video. A perfectly plated gourmet burger with melting cheese and steam rising, dramatic dark background with warm spotlight, ultra close-up food photography style, vibrant colors, 16:9."
      }
    ],
    "stream": false
  }'

Science Explainer Thumbnail

curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "Design a YouTube thumbnail for a space science video. A massive black hole warping light around it, stars streaking into the event horizon, deep blue and purple cosmic colors, dramatic and awe-inspiring, cinematic 16:9 aspect ratio."
      }
    ],
    "stream": false
  }'

Before/After Transformation Thumbnail

curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "Create a YouTube thumbnail showing a dramatic room makeover. Split down the middle: left side is a dull, cluttered room in desaturated tones, right side is the same room transformed into a stylish modern space with warm lighting and vibrant colors, 16:9."
      }
    ],
    "stream": false
  }'

Click-Through Rate Tips

• Face close-ups with exaggerated expressions consistently outperform other thumbnail styles
• 3 or fewer elements — thumbnails are viewed at ~120px wide on mobile
• High contrast between subject and background is critical
• Bright yellow, red, and orange accents draw attention in YouTube's white feed
• Consistency — use a recognizable style across your channel for brand recall

Workflow

# Step 1: Generate the base thumbnail concept
curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "YouTube thumbnail for a fitness transformation video. Athletic person mid-action with dynamic pose, bold red and black background, dramatic gym lighting, powerful and motivating, 16:9."
      }
    ],
    "stream": false
  }'

# Step 2: Refine with more specifics
curl -X POST https://eachsense-agent.core.eachlabs.run/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "messages": [
      {
        "role": "user",
        "content": "YouTube thumbnail for a fitness transformation video. Athletic person mid-action with dynamic pose, bold red and black background, dramatic gym lighting, powerful and motivating, 16:9."
      },
      {
        "role": "assistant",
        "content": "..."
      },
      {
        "role": "user",
        "content": "Add more dramatic backlighting creating a silhouette edge glow effect. Make the reds more saturated and add subtle smoke in the background."
      }
    ],
    "stream": false
  }'

Related Skills

• YouTube Content — Full YouTube channel art suite
• Social Media Post — General social media graphics
• OG Image Design — Link preview images
• Banner Ad Design — Display ad creatives

Related Models

• flux-2-max — Highest quality image generation
• flux-kontext-pro — Best for text rendering in images
• seedream-v4-5 — Creative and artistic styles
• nano-banana-pro — Fast iterations

Documentation

• each::sense Overview
• each::labs API