Generator
AI Thumbnail Generator on Martini
Generate the thumbnail that signals the video. Drop the host portrait, type the headline, fan it into 1280x720 / 1:1 / 1080x1920 / 1200x630 in one canvas pass — Ideogram bakes legible text into the composition while Nano Banana 2 keeps the host face on-model. Built for YouTubers publishing four times a week, podcasters with episode-art on every drop, and social managers shipping platform-native variants from one campaign brief. If you want the deeper workflow narrative, see /features/ai-thumbnail-generator.
What you can generate
- YouTube thumbnails at 1280x720 with readable headline baked in
- Podcast covers in Spotify and Apple square aspect ratios
- Social platform tiles for X 16:9, Instagram 1:1, and Open Graph 1200x630
- YouTube Shorts and Reels thumbnails at 1080x1920
- A/B variants with different host expression, color, or copy
- Channel re-brand refresh of historical thumbnails to a new template
- Episodic series cover packs that share a host anchor
- Ad-thumbnail variants for CTR testing across platforms
Best Martini workflow
Why this is more than a one-shot generator on Martini.
- Anchor the host portrait once on a reference node — every weekly drop fans out from the same face, so the channel stays on-model.
- Use Ideogram for the headline-baked-in pass; the in-image text lands legibly without a Figma overlay step for short copy.
- Fan out platform variants in parallel — 1280x720 / 1:1 / 1080x1920 / 1200x630 generate from one prompt instead of four manual exports.
- Save the canvas as a channel template; the next drop only changes the headline and the host expression, not the chain.
- The thumbnail is the upstream of the video campaign — the same host anchor and brand color reuse straight into the multi-shot or product-video workflow.
Recommended models
ideogram
imageIn-image text rendering is the wedge — legible headlines bake into the composition without a separate overlay step.
gpt-image-2
imageCleanup pass for text legibility, color contrast, and host-face polish before publishing.
midjourney
imageEditorial composition for hero thumbnails when the brief calls for cinematic framing.
nano-banana-2
imageHost-face fidelity from a single canonical portrait across the whole episode catalog.
flux
imageHigh-fidelity dramatic backdrops when the headline needs a denser visual base.
Prompt examples
EASY 30-MIN PASTA — host smiling holding a steaming bowl, terracotta backdrop, deep green herb pop, headline top-left in bold sans, 1280x720.
Cooking-channel YouTube thumbnail with host face anchor and bold headline baked in.
TOP 5 KNIVES — host with crossed arms, kitchen knife wall in soft focus background, dramatic side light, headline center-top in white sans, 1280x720.
Listicle-style thumbnail for a kitchen-gear channel; high-CTR host-and-product pattern.
WEEK 12: BUDGET — split layout, host on left looking concerned, $$$ stack on right, Friday vibes color palette, copy bottom-left, 1280x720.
Vlog/finance series thumbnail with split composition and recurring weekly framing.
Spotify cover — host portrait soft-lit center, channel name in 36pt italic at the bottom, neutral backdrop, 1:1 framing.
Podcast cover for Spotify and Apple Podcasts; preserves host identity across the catalog.
Open Graph share card — hero image with channel logo bottom-right, headline top, brand-color block left, 1200x630.
OG share card for blog posts and link previews; ships with logo placement preserved.
YouTube Shorts thumbnail — host pointing up at headline, vertical 1080x1920, neon-magenta backdrop, headline 60pt bold sans top-third.
Vertical Shorts thumbnail with the host gesture and headline lockup that performs on the Shorts shelf.
Channel re-brand thumbnail — host portrait three-quarter, navy backdrop, white headline in custom serif, episode number bottom-right in cyan, 1280x720.
Re-brand template; lock this composition once and re-skin every historical thumbnail off it.
Turn this output into a workflow
Generation is the first node — here's where to take it next.
Open /features/ai-thumbnail-generator for the deep-dive workflow narrative — the explainer companion to this action page.
The thumbnail signals the video — chain the host anchor into /workflows/ai-product-video for ecommerce or /workflows/multi-shot-short-film for narrative drops.
Reuse the same brand-color and host-face anchors in /features/ai-ad-creative-generator so the campaign and the channel stay visually coherent.
Pair with /prompts/image/consistent-character-prompts to keep the host face on-model across the season.
Hand off finished cuts to /features/ai-video-nle-export so the thumbnail and the video ship from the same canvas bundle.
Related features
Related how-to guides
Related prompts
Related workflows
Related reading
Frequently asked questions
How is this different from /features/ai-thumbnail-generator?
Routes are different. This generator page is action-oriented — paste a prompt, generate, fan out platform variants. The feature page is the workflow explainer (whatItSolves, whyMartini, model whitelist). Use this page to ship a thumbnail; open the feature page to plan a system.
Will the headline render legibly?
For short copy (4-8 words), Ideogram bakes the text in cleanly. For longer headlines or precise typography, generate the photographic base on Flux or Midjourney and overlay text in Figma. The cleanup pass on gpt-image-2 handles contrast and edge polish.
How do I keep the host face consistent across the season?
Anchor a single canonical portrait of the host as a reference node — every drop generates from that anchor instead of re-prompting. See /prompts/image/consistent-character-prompts for the recipe library.
Can I generate every platform variant from one prompt?
Yes — fan out 1280x720 / 1:1 / 1080x1920 / 1200x630 in parallel from one canvas prompt. Don ship 1:1 to YouTube; the platform crops kill the headline. Match the spec to the destination.
How does the thumbnail connect to the video itself?
Reuse the same host portrait and brand-color anchor across both. The thumbnail signals the video — they should share a visual lockup. Chain into /workflows/ai-product-video or /workflows/multi-shot-short-film for the campaign side.
Is clickbait imagery a problem here?
Yes. Generate a thumbnail that represents the actual video — misleading thumbnails tank long-term watch-time and channel signal. Use the host anchor to preserve trust across the catalog.
Generate it on the canvas
Open Martini, drop this generator on the canvas, and wire it into the workflow you actually need. Free to start — no card required.