Roblox Thumbnail Size (and How to Make Thumbnails People Click)

The size

From Roblox's thumbnail docs:

• Aspect ratio: 16:9. Other shapes get stretched to 16:9.
• Ideal size: 1920×1080 pixels, so it stays sharp everywhere.
• File size: keep images under 3 MB.
• Formats: .jpg, .png, .gif, .tga or .bmp.
• How many: up to 10 images or videos on your game's page.

Your icon is separate: a square image. Keep it readable at a tiny size, with one clear subject and minimal text.

What top thumbnails have in common

• The scene shows the fantasy. A giant fruit in a garden, missiles leaving a base. You know the game in one glance.
• It shows what you'll feel. Power, panic, outsmarting someone.
• One or two characters with readable faces. Big, obvious emotions.
• Simple background, high contrast. One main color that pops.
• A few words, max. Tease the twist if you have one.

Proven layouts to try

1. Before / after: level 1 vs level 999, noob base vs pro base
2. First person: great for "Be a ___" games
3. Two characters: one outplaying the other
4. One character + a clear action: running off with the loot

Check it on a phone

A huge share of Roblox players are on phones, where thumbnails are small. Text and logos that look fine on your monitor often disappear. Always preview at phone size before uploading.

Make them with AI

1. Rough out the layout using screenshots of your actual game.
2. Give an image AI a specific prompt: what's on the left, what's on the right, what's big, what the faces show.
3. Iterate: "make the logo bigger", "remove the clouds", "text can't cover the building".
4. Start a fresh chat with your best image if it keeps getting it wrong.

Test, don't guess

Your first thumbnail is rarely your best. Make several, test them in an ad campaign, keep the winners, and keep adding new ones as click-through drops over time.

More on getting the click: how to get players on your Roblox game.