Thumbnail Maker

Thumbnail generator. Input: title + optional face photo + optional style. Output: N variants at 16:9 (YouTube / blog / podcast-episode thumbnail).

Distinct from cover-maker:

• Aspect: ALWAYS 16:9 (no medium variation)
• Aesthetic: bright contrast, large text, exaggerated facial expressions — "thumbnail look"
• Variants vary in FACE PLACEMENT (left / right / center) more than in style

Distinct from flyer-maker:

• No event details (date / location)
• Stronger emphasis on the FACE if photo provided
• Different typography conventions (bigger, often colored, with stroke / shadow)

This skill does NOT:

• Generate YouTube banner art (different aspect — use cover-maker --aspect 2560x1440 or image-prompt --execute)
• Generate animated thumbnails — static images only
• Source rights-cleared face references — provide your own
• Optimize for click-through (subjective — picks best of 3-5 manually)

ROLE

Read title + optional face → pick model (text-friendly + ref-capable) → assemble per-variant prompts with face-placement + bold title composition → batch execute → save PNGs.

PIPELINE

1. Resolve title:

• Required: --title
• 3-7 words is the sweet spot for thumbnails
• High-energy phrasing works best ("How I Built X in 30 Days", "STOP DOING THIS")

1. Resolve photo (optional):

• --photo — face reference
• Identity preserve via Nano Banana Pro (default)

1. Resolve style — see references/composition-zones.md:

• --style auto: picks vibrant + text-friendly styles
• Default for "YouTube look": gradient-mesh-modern or swiss-grid-poster with vibrant accent

1. Face placement variants:

• --placements left,right,center — default left,right,center (3 variants)
• The same face / title / style; placement varies
• Maximizes the chance of "the one that works for click"

1. Pick model:

• Photo + face → nano-banana-pro (identity preserve)
• No photo + heavy text → ideogram-3-quality
• Mixed → gpt-image-2

1. Build per-variant prompts — composition zones per placement (face-left + text-right; face-right + text-left; face-center-bottom + text-top).

1. Batch execute — parallel.

1. Output:

`` ./generated/thumbnail// thumbnail-left.png (face left, text right) thumbnail-right.png (face right, text left) thumbnail-center.png (face center, text top) manifest.json style-used.md prompts.md ``

MODES

Required

• thumbnail-maker --title ""

Optional

• --photo — face / subject reference
• --subtitle "" — secondary line (rare for thumbnails)
• --style auto| — visual style
• --style-mod "" — tweak
• --placements left,right,center,top,bottom — comma list (default left,right,center)
• --variants N — variants per placement (default 1; >1 gives N takes per placement)
• --lang en|ru — language hint
• --model auto| — provider
• --aspect WxH — override default 1920×1080 (e.g., 1280x720 for low-res)

Type presets

• --type youtube — 1920×1080 (default), bright + bold aesthetic
• --type blog — 1200×630 (OG image standard), more editorial
• --type podcast-episode — 1920×1080 with podcast-cover-feel

Execution

• --execute — actually generate
• --output — custom output
• --parallelism N — concurrent calls
• --yes — skip cost confirmation
• --resume — retry failed
• --prompts-only — dry run

REFERENCES (load on demand)

| File | When to load | |---|---| | [references/model-picker.md](references/model-picker.md) | Step 5 — model auto-pick + capability matrix | | [references/composition-zones.md](references/composition-zones.md) | Step 6 — per-placement composition templates, face + text positioning | | [references/troubleshoot.md](references/troubleshoot.md) | When face placement collides with text, contrast issues, click-bait avoidance |

EXAMPLES

See [examples/before-after.md](examples/before-after.md) — 3 calibration runs: YouTube tutorial thumbnail with creator face, blog header without photo, podcast episode cover with guest portrait.

CONSTRAINTS

• Title 3-7 words. Past 7, text crowds + becomes unreadable at thumbnail scale.

• Title is THE focal point. Even with a face, the title must be readable at 320×180px (small thumb on mobile).

• One face per thumbnail. Multiple faces compete; pick one main subject.

• Face placement variants are stochastic. "Left" / "right" / "center" guide the model but don't lock pixel-perfect.

• Bright contrast is the YouTube look. The default --style auto biases toward vibrant + high-contrast styles. Override with --style photo-editorial-bw for editorial blog feel.

• Don't add too many text elements. Title + optional subtitle = max 2. Past that, thumbnail looks crowded.

• Reasonable click-bait avoidance. The skill doesn't enforce "non-clickbait" — that's editorial judgment. But it also doesn't artificially exaggerate facial expressions unless you ask via --style-mod "exaggerated shock expression".

• One model across the variant set. Lock per-thumbnail.

• Cost confirm ONCE. Sum across placements × variants.

• Per-platform image sizing:
• YouTube: 1280×720 minimum, 1920×1080 high-res
• Blog OG image: 1200×630
• Podcast episode art: 1920×1080
• LinkedIn article cover: 1200×627

• Never print API keys. Mask in errors.

INVOCATION HINTS

When the user says any of:

• "YouTube thumbnail", "blog header image", "podcast episode cover"
• "thumbnail for my video", "create thumbnail variants"
• "обложка для YouTube видео / поста / эпизода"
• "превью для видео"

If unclear, default to --type youtube. If user mentions "blog post" → --type blog. If "podcast episode" → --type podcast-episode.

Defaults: --type youtube --placements left,right,center --style auto --model auto. Without --execute, returns prompts.

This skill is distinct from:

• cover-maker — that's albums/books/podcasts (general "cover" with title + creator). This is specifically thumbnail-aspect content marketing.
• flyer-maker — events. This is content marketing.
• avatar-maker — single-subject portrait. This adds text + 16:9 framing.
• image-prompt — free-form. This is structured thumbnail conventions.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Mikefluff
• Source: Mikefluff/skills
• License: MIT
• Homepage: https://www.npmjs.com/package/@mikefluff/skills

Install and usage instructions live in the source repository linked above.