youtube-thumbnail-maker
Skill1 starsChanged 47 days agoMITView on GitHub
Design YouTube thumbnail concepts and render a 1280×720 image (HTML to PNG) ready to upload in YouTube Studio. Use when the user asks for a YouTube thumbnail maker, thumbnail ideas, a thumbnail for a video, or to make or improve a YouTube thumbnail.
3 other projects use a version of this.
Adopted by
Most recently taken up by
- RoxenRoblox/claude-skillstheir own version, first seen Oct 13, 2026
- JaydonDiaz/claude-skillstheir own version, first seen Oct 13, 2026
- sithumdgomez/claude-skillstheir own version, first seen Oct 11, 2026
Other versions3 projects use a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 3
- JaydonDiaz/claude-skills★ 0same name
- RoxenRoblox/claude-skills★ 0same name
- sithumdgomez/claude-skills★ 0same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository8 other files it gives its agents.
The file
We split this skill into the rules it gives an agent
2 rules. 0 are common, 2 are distinctive, and 0 are very specific to this project.
0
Common
Most of the 3 edited versions we read keep these.
2
Distinctive
This author's own choices. Worth a look.
0
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Distinctive: line 23
Keep text and faces out of the bottom-right corner: the video length covers it.
- Distinctive: line 40
If the environment can render HTML to PNG (for example headless Chrome or Playwright), build the chosen concept as a fixed-size HTML page:
“Common” is measured: kept by at least 6 in 10 of the 3 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
YouTube thumbnail maker
Plan three thumbnail concepts for one video, render the chosen one, and hand the file to the user.
Upload it yourself in YouTube Studio. The PostOnce MCP does not set custom YouTube thumbnails. After the video is up, open it in YouTube Studio > Content > Details > Thumbnail > Upload file. YouTube only allows custom thumbnails on channels with intermediate features turned on (phone verification).
Before designing
Get or infer: the video title (the thumbnail must pair with it, not repeat it), the one promise of the video, the channel's colors and fonts, and any assets: a face photo with an expression, a product shot, a screenshot, a before/after. Never fake a result, screenshot or number the video doesn't show.
Specs
- 1280×720 pixels, 16:9. Minimum width 640.
- JPEG or PNG, 2 MB or less. Export PNG, and convert to JPEG if it's over 2 MB.
- Keep text and faces out of the bottom-right corner: the video length covers it.
What makes a thumbnail work
- One focal point: a face with a clear emotion, one object, or one contrast. Readable at phone size in suggested videos.
- 0–4 words of text, large and bold, adding what the title doesn't say. Never the full title.
- High contrast between subject and background; a clean, simple background.
- Show the stakes or the result: before/after, the finished thing, the mistake circled.
- Same style across a channel so viewers recognize it, but each thumbnail distinct.
- For Shorts, YouTube mostly uses a frame from the video; design the first frame instead.
Concepts
Return three concepts, each with: the idea in one line, the layout (subject position, text position), the exact text (0–4 words), colors, and which assets it needs.
Rendering
If the environment can render HTML to PNG (for example headless Chrome or Playwright), build the chosen concept as a fixed-size HTML page:
<body>exactly 1280×720,margin: 0,overflow: hidden, one root element at that size.- Local or inline assets and fonts only, so the render is deterministic.
- Screenshot at 1280×720 (device scale factor 1) to PNG, check the file size, and look at a small preview (about 320×180) to confirm it still reads.
Otherwise hand the user the layout, text, colors and asset list for Canva, Figma or Photoshop.
Output
Give the three concepts, mark the pick, and deliver the rendered PNG path (or the design brief). Remind the user to upload it in YouTube Studio once the video is live. Offer to publish or schedule the video itself with the postonce skill, and to write the title with youtube-title-generator so the pair works together. Confirm the channel, privacy and time before calling create_post.
Does it work?
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Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.