YouTube watermark size: 150×150 minimum, under 1 MB

A YouTube video watermark must be a square image of at least 150×150 pixels and less than 1 MB in size. You choose whether it shows for the last 15 seconds of a video, from a custom start time, or for the entire video, and it isn't available on videos set as made for kids.

YouTube's rules are quoted from its help page Manage your channel branding, read on 2026-09-28. Sume facts come from the Image API docs and the background-removal schema in the Sume API reference; anything called current code is read from Sume's source.

What size should a YouTube watermark be?

Square, at least 150×150 pixels, and under 1 MB. The page lists no maximum pixel size, so the 1 MB file limit is the ceiling it does set. A subscribe-button design follows the same rules: they apply to whatever the square image shows. The watermark is one of three branding images YouTube sets under Customization. The profile picture has different limits, below, and the channel banner's are in AI banner generator for YouTube.

When does the watermark show, and where is it hidden?

You pick the display time when you add the image, and YouTube adds these limits:

• End of video shows it for the last 15 seconds; Custom start time starts it at a time you choose; Entire video shows it throughout.
• It isn't available on videos set as made for kids. If a video with a watermark is later set as made for kids, viewers won't see it.
• It shows in landscape view on computers and mobile devices, and it isn't clickable on mobile. It doesn't show on custom YouTube chromeless players or Adobe Flash.
• End screens suppress it, along with card teasers, per Add end screens to videos. YouTube end screen template covers those last 5–20 seconds.
• Its metrics are in the Subscription source report in YouTube Analytics.

How do I make a YouTube watermark with AI?

Generate a square mark, cut it out, then check the file before you upload it. With the Sume API, ask POST /v1/images for a 1:1 image from ChatGPT Image 2.5 (openai/gpt-image-2.5) in png. Keep the design bold and simple, on a plain background that contrasts with the mark. If it includes lettering, proofread every letter, as AI image with text explains.

• n asks for several candidates in one call. The docs allow up to 10 per call, with a lower ceiling in each model's n range; in current code this model's range is 1 to 4.
• Result URLs in data[].url are Sume-hosted and signed, so download the file you keep.
• Cut the chosen image out with POST /v1/rmbg-1.0/remove: a completed job returns PNG artifacts with alpha. Remove background API has the request.
• YouTube's page doesn't mention transparency, so look at the watermark on one of your videos after you publish it.
• Check the download: square, at least 150×150, under 1 MB. If it's too heavy, scale it down; YouTube suggests your computer's image editor or an online image resizer.

curl -X POST "https://api.sume.com/v1/images" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Flat channel badge: a bold orange paper-plane icon inside a white circle, thick outline, centered, plain dark blue background, no text",
    "aspect_ratio": "1:1",
    "output_format": "png",
    "n": 4
  }'

How do I add the watermark, and what does it cost?

In YouTube Studio, the watermark sits under Customization, then Profile: select the display time, click CHANGE, pick the image, adjust its size, click DONE, then PUBLISH.

On Sume, each image model lists its rates in the pricing line of GET /v1/images/models/{model_id}/endpoints, and usage.cost in the response is the amount billed. API pricing lists background removal at $0.0225 per image, plus a 5.5% agent fee by default.

Is a watermark the same as a logo burned into the video?

No. The watermark is a separate image, set in YouTube Studio's Customization settings rather than in the video file, that YouTube shows over your videos on YouTube. A logo burned into the frames is part of the video file, so it shows wherever the file plays. For that, see How to add a logo or watermark to a video.