Skills / Make a thumbnail
Make a thumbnail
Make a thumbnail that tells the truth and earns the click. Composition, text readable at small size, correct export. Use when they say "make me a thumbnail" or they are about to upload a video where thumbnails matter.
Use this skill. Nothing to install.
Don't have an agent? · Raw file: skills/make-a-thumbnail.md
Watch the first two minutes
This is how a session goes when thumbnail advice has already put you off thumbnails. Click through it.
Scripted example of a real session.
Isn't this just clickbait?
A thumbnail is a promise about what the video contains, and the skill's whole job is making that promise vivid without lying. No shocked face you never make, no arrows at things that are not in the video, no "you won't believe" framing over ordinary content. Ordinary content with an honest, legible, high-contrast thumbnail beats the same content behind a bait one, because a viewer who got what the thumbnail promised stays, and the platforms measure that. The craft is composition and contrast, and the skill teaches both on your own footage.
What you end up with
An exported image, tested at the size people will actually see it, plus the decisions behind it. Here is the spec from the bike-repair session above.
- One subject. Thumbnails with three subjects have zero. Everything else in the frame exists to make the one subject read.
- The text does a different job than the title. They appear on the same screen, so saying the same thing twice wastes the strongest four words you get.
- The small test is the gate. Thumbnails are seen at postage-stamp size on phones. Nothing ships until it survives 120 pixels.
Anatomy of a thumbnail that reads
The skill checks every draft against this line:
- A A face, an object, or a moment from the video. Faces are strong because eyes read at any size.
- B Contrast carries the image. If the frame grab is flat, brightness and contrast get bumped before anything gets added.
- C Text is optional and expensive. A busy background means a solid or shadowed backing behind it.
- D The only verdict that matters, checked by zooming out or looking at the export in icon view.
Questions people actually ask
Is this free?
The skill is free and so are the tools it uses: Canva free tier, Figma, GIMP, or even Google Slides. Photos come from your own footage or a phone photo you shoot during the session.
I'm not a designer. Can I really make one?
Yes, because the method is narrow: one subject, filled frame, high contrast, few words. The small test tells you honestly whether it worked, and a second draft takes minutes.
Should my face be in it?
If your face is in the video, it is a strong candidate, because eyes read at any size. The expression has to be one you actually make in the video. A staged shocked face over calm content is exactly what the skill refuses.
Do TikTok, Reels, and Shorts need thumbnails too?
Vertical platforms take a cover frame from the video itself, so the job there is picking that frame deliberately at upload. The full 1280x720 thumbnail is for YouTube.
What if I can't choose between two ideas?
Make both; it is ten minutes. Compare them at small size and pick on legibility and honesty. If the platform offers thumbnail testing, YouTube does, let real viewers settle it.
Where to go from here
The thumbnail is one piece of the upload. The rest:
No video yet? Make one worth a thumbnail:
Curious? Read the full skill — the exact instructions your agent gets
--- name: make-a-thumbnail category: media description: Make a thumbnail that tells the truth and earns the click. Composition, text readable at small size, correct export. Use when they say "make me a thumbnail" or they are about to upload a video where thumbnails matter. --- # make-a-thumbnail Make a thumbnail with someone for a real video they made. A thumbnail is a promise about what the video contains; the job is to make that promise vivid without lying. The session ends with an exported image, tested at the size people will actually see it. ## Ground rules - The thumbnail must be true. It shows something that happens in the video, in the video's actual tone. No shocked-face they never make, no red arrows pointing at things that are not in the video, no "you won't believe" framing over ordinary content. Truthful and clickable are compatible; that is the craft. - Free tools: Canva free tier, Figma, GIMP, or even Google Slides. Photos come from their own footage — a frame grab from the video or a photo they shoot right now on their phone. ## Composition 1. Pick the subject: one face, one object, or one moment from the video. One. Thumbnails with three subjects have zero. 2. Frame grab or reshoot: scrub the video for a frame where the subject is sharp and well-lit, or stage the same real moment for a phone photo with better light (face a window). 3. Fill the frame. The subject should take a third to a half of the image. Faces work because eyes read at any size — if their face is in the video, it is a strong candidate for the thumbnail. 4. Contrast carries it: subject light against dark background or dark against light. If the grab is flat, bump contrast and brightness in the editor rather than adding decoration. 5. Text only if it adds what the image cannot say: 3–4 words max, heavy bold font, high contrast (add a solid or shadowed backing if the background is busy). The text and the video title should not say the same thing — they share the same screen. ## The small test Thumbnails are seen at postage-stamp size on phones. Before calling it done: - Zoom the canvas out until the image is about 120 pixels wide, or export and look at it in a file browser icon view. - Can you tell what it is? Can you read the text? If not, bigger subject, fewer words, more contrast — repeat until it survives. - Line it up next to a screenshot of the platform's feed. It should hold its own without imitating anyone specific. If they are choosing between two ideas, make both — it is ten minutes — and compare at small size. Pick on legibility and honesty, then note which one ran; if the platform offers thumbnail testing (YouTube does), let real viewers settle it. That is A/B thinking without inventing anything. ## Done - Check the destination's current official dimensions, aspect ratio, format, and file-size limit before export. For platforms that select a video frame, choose that frame deliberately during upload. - The exported file is saved next to the video, named to match. - Both of you have seen it at real size and agree it promises only what the video delivers. Uploading next? The publish-to-youtube skill covers the rest of the package: title, description, and what to watch after it goes live.





