ThumbAPI Documentation
ThumbAPI is a REST API that generates production-ready thumbnails from any title. Send a title, pick a format, get an image — in under 25 seconds.
What You Can Build
- YouTube thumbnails (1280x720) from video titles
- OG images (1200x630) for blog posts and social sharing
- Instagram images (1024x1024) from content titles
- X/Twitter cards (1200x675) for social posts
- LinkedIn images (1200x627) for posts and shares
Quick Overview
POST https://api.thumbapi.dev/v1/generate
x-api-key: YOUR_API_KEY
Content-Type: application/json
{
"title": "How to Build a SaaS in 2026",
"format": "youtube",
"category": "tech-saas"
}
The API returns a base64-encoded WebP image, the format used, and the output format. Add usePhoto: true to include your saved photo, useLogo: true to overlay your logo, or both.
Getting Started
- Get your API key — free, no credit card
- Follow the quickstart — first thumbnail in 5 minutes
- Read the endpoint reference — every parameter explained
Available Formats
| Format | Dimensions | Use Case |
|---|---|---|
youtube | 1280 x 720 | YouTube video thumbnails |
blogpost | 1200 x 630 | Blog featured images, OG images |
linkedin | 1200 x 627 | LinkedIn posts and shares |
instagram | 1024 x 1024 | Instagram post images |
x | 1200 x 675 | X/Twitter card images |
format becomes optional when you pass a customAssetsId — the stored format on the reference set wins.
Photo & Logo
usePhoto and useLogo are independent boolean flags — use either, both, or neither.
| Flag | Description |
|---|---|
usePhoto: true | Integrate your saved Personal Photo as the main subject. Override per-request with photoImage (data-URL, max 2MB). |
useLogo: true | Overlay your saved Logo on the final image. Override per-request with logoImage (data-URL, max 1MB). |
Omit both for a faceless thumbnail (the default).
Legacy imageStyle / personImage / usePersonalPhoto parameters are still accepted for backward compatibility, but prefer the new flags in fresh code.
Pricing
| Plan | Credits/month | Price | Watermark | 2K quality |
|---|---|---|---|---|
| Free | 50 | $0 | Yes | — |
| Creator | 750 | $19/month | — | — |
| Pro | 2,500 | $49/month | — | ✓ |
| Business | 10,000 | $199/month | — | ✓ |
A standard 1K thumbnail costs 10 credits (2K costs 20). Each enabled add-on (photo, logo, custom reference set) adds 2 credits. Failed generations are refunded automatically. View pricing →
Next Steps
- Quickstart guide — zero to first thumbnail
- Authentication — getting and using your API key
- Custom assets — use your own photos, logos, and style references
- Code examples — copy-paste snippets for cURL, JS, Python