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YouTube thumbnail size checker

YouTube Help recommends 3840 x 2160 pixel thumbnails at 16:9 for videos, with a minimum width of 640 pixels. For Shorts it recommends 2160 x 3840 at 9:16. Drop an image here to check it before you upload.

Try it

PlacementSize
Video thumbnail3840 x 2160
Shorts thumbnail2160 x 3840

File limit: 2 MB from mobile (10 MB for podcasts), 50 MB from desktop, per YouTube Help.

Drop a local file to check it. Nothing is uploaded.

How it works

  1. 1

    Drop in your image. The browser reads it, and nothing is uploaded.

  2. 2

    The checker compares width, height, ratio and file size with YouTube Help.

  3. 3

    It marks each limit as a pass or fail.

  4. 4

    You see whether the file is ready to upload.

Platform facts

FAQ

What size should a YouTube thumbnail be?
3840 x 2160 pixels at 16:9, and at least 640 pixels wide, per YouTube Help.
What about Shorts thumbnails?
2160 x 3840 at 9:16, and at least 640 pixels tall. YouTube Help says custom Shorts thumbnails can only be added in YouTube Studio on a computer.
How big can the file be?
2 MB when you upload from a phone, 50 MB from a computer.

Optional next step

Schedule the upload from your agent

With UniPost connected, Claude, Cursor or Grok Bot can upload a video to your YouTube channel and set when it goes out. Your first 2 accounts are free.

Connect your agentBrowse all free tools

Related tools

Also see YouTube MCP server

Sources