matrixy Install the belt CLI skill:
npx skills add belt-sh/cli
OG Image Design
Create social sharing images (Open Graph) via inference.sh CLI.
Quick Start
Requires inference.sh CLI (
belt). Install instructions
belt login
# Generate an OG image with HTML-to-image
belt app run infsh/html-to-image --input '{
"html": "<div style=\"width:1200px;height:630px;background:linear-gradient(135deg,#1a1a2e,#16213e);display:flex;align-items:center;padding:60px;font-family:system-ui;color:white\"><div><h1 style=\"font-size:56px;margin:0;line-height:1.2\">How We Reduced Build Times by 80%</h1><p style=\"font-size:24px;opacity:0.8;margin-top:20px\">engineering.yourcompany.com</p></div></div>"
}'
Platform Specifications
| Platform | Dimensions | Aspect Ratio | File Size | Format |
|---|---|---|---|---|
| 1200 x 630 px | 1.91:1 | < 8 MB | JPG, PNG | |
| Twitter/X (summary_large_image) | 1200 x 628 px | 1.91:1 | < 5 MB | JPG, PNG, WEBP, GIF |
| Twitter/X (summary) | 800 x 418 px | 1.91:1 | < 5 MB | JPG, PNG |
| 1200 x 627 px | 1.91:1 | < 5 MB | JPG, PNG | |
| Discord | 1200 x 630 px | 1.91:1 | < 8 MB | JPG, PNG |
| Slack | 1200 x 630 px | 1.91:1 | — | JPG, PNG |
| iMessage | 1200 x 630 px | 1.91:1 | — | JPG, PNG |
Universal safe bet: 1200 x 630 px, PNG or JPG, under 5 MB.
The Golden Layout
┌──────────────────────────────────────────────────┐
│ │
│ ┌─────────────────────────────────┐ ┌───────┐ │
│ │ │ │ │ │
│ │ Title Text (max 60 chars) │ │ Logo/ │ │
│ │ ─────────────────── │ │ Visual│ │
│ │ Subtitle (max 100 chars) │ │ │ │
│ │ │ │ │ │
│ │ author / site name │ └───────┘ │
│ └─────────────────────────────────┘ │
│ │
└──────────────────────────────────────────────────┘
1200 x 630 px
Design Rules
Text
| Rule | Value |
|---|---|
| Title font size | 48-64px |
| Subtitle font size | 20-28px |
| Max title length | 60 characters (gets truncated on some platforms) |
| Max subtitle length | 100 characters |
| Line height | 1.2-1.3 for titles |
| Font weight | Bold/Black for title, Regular for subtitle |
| Text contrast | WCAG AA minimum (4.5:1 ratio) |
Safe Zones
┌──────────────────────────────────────────────────┐
│ ┌──────────────────────────────────────────────┐│
│ │ 40px padding from all edges ││
│ │ ││
│ │ Content lives here ││
│ │ ││
│ │ ││
│ └──────────────────────────────────────────────┘│
└──────────────────────────────────────────────────┘
- 40px minimum padding from all edges
- Some platforms crop edges or add rounded corners
- Never put critical text in the outer 5%
Colors
| Background Type | When to Use |
|---|---|
| Solid brand color | Consistent series, corporate |
| Gradient | Modern, eye-catching |
| Photo with overlay | Blog posts, editorial |
| Dark background | Better contrast, stands out in feeds |
Dark backgrounds outperform light in social feeds — most feeds have white/light backgrounds, so dark OG images pop.
Templates by Content Type
Blog Post
belt app run infsh/html-to-image --input '{
"html": "<div style=\"width:1200px;height:630px;background:linear-gradient(135deg,#667eea,#764ba2);display:flex;align-items:center;padding:60px;font-family:system-ui,sans-serif;color:white\"><div style=\"flex:1\"><p style=\"font-size:18px;text-transform:uppercase;letter-spacing:2px;opacity:0.8;margin:0\">Engineering Blog</p><h1 style=\"font-size:52px;margin:16px 0 0;line-height:1.2;font-weight:800\">How We Reduced Build Times by 80%</h1><p style=\"font-size:22px;opacity:0.9;margin-top:16px\">A deep dive into our CI/CD optimization</p></div></div>"
}'
Product/Launch Announcement
belt app run infsh/html-to-image --input '{
"html": "<div style=\"width:1200px;height:630px;background:#0f0f0f;display:flex;align-items:center;justify-content:center;font-family:system-ui;color:white;text-align:center\"><div><p style=\"font-size:20px;color:#22c55e;text-transform:uppercase;letter-spacing:3px\">Now Available</p><h1 style=\"font-size:64px;margin:12px 0;font-weight:900\">DataFlow 2.0</h1><p style=\"font-size:24px;opacity:0.7\">Automated reports. Zero configuration.</p></div></div>"
}'
Tutorial/How-To
belt app run infsh/html-to-image --input '{
"html": "<div style=\"width:1200px;height:630px;background:linear-gradient(to right,#1a1a2e,#16213e);display:flex;align-items:center;padding:60px;font-family:system-ui;color:white\"><div><div style=\"display:inline-block;background:#e74c3c;color:white;padding:8px 16px;border-radius:4px;font-size:16px;font-weight:bold;margin-bottom:16px\">TUTORIAL</div><h1 style=\"font-size:48px;margin:0;line-height:1.2\">Build a REST API in 10 Minutes with Node.js</h1><p style=\"font-size:20px;opacity:0.7;margin-top:16px\">Step-by-step guide with code examples</p></div></div>"
}'
AI-Generated Visual OG
# When you want a striking visual instead of text-based
belt app run falai/flux-dev-lora --input '{
"prompt": "clean professional social sharing card, dark gradient background, abstract geometric shapes, modern tech aesthetic, minimal, no text, 1200x630 equivalent aspect ratio",
"width": 1200,
"height": 630
}'
OG Meta Tags Reference
<!-- Essential (Facebook, LinkedIn, Discord, Slack) -->
<meta property="og:title" content="Title here (60 chars max)" />
<meta property="og:description" content="Description (155 chars max)" />
<meta property="og:image" content="https://yoursite.com/og-image.png" />
<meta property="og:url" content="https://yoursite.com/page" />
<meta property="og:type" content="article" />
<!-- Twitter/X specific -->
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:title" content="Title here" />
<meta name="twitter:description" content="Description" />
<meta name="twitter:image" content="https://yoursite.com/og-image.png" />
<!-- Image dimensions (optional but recommended) -->
<meta property="og:image:width" content="1200" />
<meta property="og:image:height" content="630" />
Twitter Card Types
| Card Type | Image Size | Use When |
|---|---|---|
summary |
800 x 418 (small thumbnail) | Short updates, links |
summary_large_image |
1200 x 628 (full width) | Blog posts, articles, announcements |
Always use summary_large_image unless you have a specific reason not to — the large image gets significantly more clicks.
Consistency System
For a blog or site with many pages, create a template system:
| Element | Keep Consistent | Vary |
|---|---|---|
| Background style | Same gradient or brand colors | — |
| Font family | Same font | — |
| Layout | Same positioning | — |
| Logo/branding | Same placement (corner) | — |
| Category badge | Same style | Color per category |
| Title text | Same size/weight | Content changes |
Testing OG Images
| Tool | URL |
|---|---|
| Facebook Debugger | developers.facebook.com/tools/debug/ |
| Twitter Card Validator | cards-dev.twitter.com/validator |
| LinkedIn Post Inspector | linkedin.com/post-inspector/ |
| OpenGraph.xyz | opengraph.xyz |
# Research OG debugging tools
belt app run tavily/search-assistant --input '{
"query": "open graph image debugger preview tool test og:image"
}'
Common Mistakes
| Mistake | Problem | Fix |
|---|---|---|
| No OG image at all | Platform shows random page element or nothing | Always set og:image |
| Text too small | Unreadable on mobile previews | Title minimum 48px at 1200px width |
| Light background | Gets lost in white/light feeds | Use dark or saturated backgrounds |
| Too much text | Cluttered, overwhelming | Max: title + subtitle + brand |
| Image too large (>5MB) | Some platforms won't load it | Optimize to under 1MB ideally |
| No safe zone padding | Text cropped on some platforms | 40px padding from all edges |
| Different image per platform | Inconsistent sharing experience | Use 1200x630 for everything |
| HTTP image URL | Many platforms require HTTPS | Always serve OG images over HTTPS |
| Relative image path | Won't resolve when shared | Use full absolute URL |
Related Skills
npx skills add inference-sh/skills@ai-image-generation
npx skills add inference-sh/skills@landing-page-design
npx skills add inference-sh/skills@prompt-engineering
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