Real outputs
Rendered with this skill on our machine, unedited.
How to use
- 1
Copy the install prompt
Click the black button. One click, done.
- 2
Paste it to your agent
Send it in Claude Code, Codex, Cursor or similar. It installs itself.
- 3
Ask in one sentence
Say what you want, like below, and the agent follows this skill.
/youtube-thumbnail-lab make me: YouTube and B站 creatorsExample message showing how to invoke it, not a real output.
What you get
- 1280x720 thumbnails for the chosen concepts
- A concept table to pick from or A/B test
- Small-size readability check before you publish
Good fit
- YouTube and B站 creators
- A/B testing thumbnails
- Channels without a thumbnail designer
Not for
- Using a real person's face without a reference photo
- Misleading clickbait
What you need
- Python 3.9+ (standard library only)
- OPENAI_API_KEY (+ OPENAI_BASE_URL for gateways)
- Pillow for exact-size crops (optional)
- ≈ $0.04 per medium 1536px image
- License
- Proprietary (Skilloop Pro)
- Author
- @Skilloop
- Version
- v1.0.0
- Output
- Image
- Generates with
- GPT Image 2 via any OpenAI-compatible API (your key)
Built and maintained by Skilloop (Pro). Every sample below was produced by this exact skill. Source packages are proprietary — not MIT.
Package contents
- youtube-thumbnail-lab/LICENSE
- youtube-thumbnail-lab/SKILL.md
- youtube-thumbnail-lab/examples/saas-48-hours.prompt.txt
- youtube-thumbnail-lab/examples/seven-ai-video-tools.prompt.txt
- youtube-thumbnail-lab/scripts/crop.py
- youtube-thumbnail-lab/scripts/generate.py
- youtube-thumbnail-lab/templates/concepts.md
- youtube-thumbnail-lab/templates/prompt-template.md
SKILL.md
Design click-worthy YouTube / Bilibili thumbnails (1280x720) from a video title — writes 3 concept directions (face+reaction, object+text, before/after), generates the chosen ones with GPT Image via any OpenAI-compatible API, and checks readability at small size. Use for YouTube thumbnail, B站封面, video cover, thumbnail A/B test.
Unlock with Pro
Skilloop Originals are included with Pro, or you can buy one Original once. Preview stays open; install, ZIP and install.md need Pro or a purchase of that skill.
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