What a clickable thumbnail is made of
Viewers see a thumbnail in their feed as a small rectangle on a phone screen. In a fraction of a second it has to explain what the video is about and spark interest.
- A face with an emotion. Surprise, delight, doubt. A live emotion in close-up catches the eye.
- A large caption of 2 to 5 words. It complements the video title rather than repeating it.
- Contrast. A bright solid background, a dark outline around light text.
- One main subject. The face and, if needed, the object the video is about. No small details.
- A free zone in the bottom right. On YouTube the video length sits there.
Step by step
1. Photo. Upload a sharp front-facing photo of your face in good light. You do not have to act out the emotion: the model will add it.
2. Prompt. Start with «keep the face unchanged», then the emotion, pose, background, the caption in quotation marks and the 16:9 format.
3. Generation. Nano Banana Pro, 2K resolution. Make 2 or 3 variants.
4. Check. Shrink the image to the size of a phone screen and check whether the caption is readable. Check every letter.
5. Size. YouTube recommends 1280×720 pixels. If needed, scale the image down in any editor.
Ready-made prompts
Surprise and pointing at the text:
Keep the face of the person in the photo unchanged. A YouTube thumbnail: the person on the left with a surprised expression points to the right, a bright yellow background. On the right, a large white caption with a black outline: «5 ОШИБОК НОВИЧКА». 16:9 format.
The caption means «5 BEGINNER MISTAKES».
Before and after:
Keep the face of the person in the photo unchanged. The thumbnail is split into two halves: on the left a tired person on a grey background with the caption «ДО», on the right the same person smiling on a bright green background with the caption «ПОСЛЕ». A large bold font. 16:9 format.
The captions mean «BEFORE» and «AFTER».
Object in hand:
Keep the face of the person in the photo unchanged. The person on the right holds a smartphone and looks at it with delight, a dark blue background with a soft glow. On the left, a large caption «ЭТО РАБОТАЕТ?» in a white bold font. 16:9 format.
The caption means «DOES IT WORK?».
Expert video:
Keep the face of the person in the photo unchanged. The person in a blazer on the right, a confident look, a light background with a blurred office. On the left, a two-line caption «КАК НАЙТИ / КЛИЕНТОВ» in a dark bold font. 16:9 format.
The caption means «HOW TO FIND / CLIENTS».
Cover for VK Video: the same prompts work for VK covers, the format is also 16:9.
More wording: prompts for Nano Banana Pro.
Checklist before uploading
- The caption is readable on a phone screen.
- The text has no mistakes: Nano Banana Pro writes Cyrillic legibly but sometimes mixes up a letter in long words.
- The face looks like you. If it has «drifted», regenerate from the source photo.
- There are no important details in the bottom right corner: the video length will be there.
- The thumbnail has no other people’s faces, logos or film stills: brands, logos and characters in AI.
- The thumbnail honestly reflects the video’s content: clickbait that the video does not deliver on lowers retention.
Test variants
A 25-ruble cover lets you test instead of guessing. Make 2 or 3 variants with a different emotion or caption and compare which one gets more clicks. YouTube has a feature for testing several thumbnails for one video.
How much it costs
| What | Generations | Approx. |
|---|---|---|
| 1 thumbnail, 2K | 1 | ~25 rubles |
| 3 variants for a test | 3 | ~76 rubles |
| Thumbnails for a month, 8 videos with 2 variants each | 16 | ~400 rubles |
KADR prices, October 2026. This is not a public offer. Prices of other image models: how much it costs to generate an AI image.
In short
AI makes a YouTube thumbnail or a VK cover in one go: your face with the right emotion, a bright background and a Russian caption of 2 to 5 words, in 16:9 format. Use Nano Banana Pro, start the prompt with «keep the face unchanged», write the text word for word in quotation marks and check readability on a phone. A cover costs about 25 rubles, so make several variants and test them.
