You open YouTube Studio, click a video, and the custom thumbnail option is grayed out, missing, or throws an error. It feels like a bug, but it's almost always one of a few account or file settings. If you can't add a custom thumbnail, work through these causes from the most common to the least.
Cause 1: your account isn't verified
YouTube asks channels to verify with a phone number before they can use a custom thumbnail. This is the most common reason the option is locked.
- Open YouTube Studio and select a video, or go to Settings and look for the channel feature eligibility section.
- If you see a Verify or Enable prompt, choose it.
- Pick whether to receive a code by text or voice call, enter your phone number, and submit.
- Enter the six-digit code you receive.
After verification, sign out, sign back in, and reload Studio. The option sometimes doesn't appear in a tab that was already open. A single phone number can only verify a limited number of channels in a year, which can be a problem if you run several channels.
Cause 2: your channel has a restriction
Channels with active Community Guidelines strikes or certain restrictions may lose access to some features, including custom thumbnails. Check the Channel status and features area of YouTube Studio for any warnings, and resolve those first.
Cause 3: you don't have the right role
If someone else owns the channel and you're only a manager or editor, some options can be limited depending on your permissions. Ask the channel owner to check your role, or to upload the thumbnail themselves.
Cause 4: the file doesn't meet the rules
A thumbnail can be refused because of its format, size, or shape.
- Format: use JPG or PNG.
- File size: the limit is 2 MB on the mobile app and 50 MB on desktop, per YouTube's current help page.
- Ratio and width: use 16:9 with a minimum width of 640 pixels.
Drop your file into the thumbnail size checker to see which rule it breaks. Our size guide lists the current numbers.
Cause 5: you're trying to do it in the wrong place
- Shorts: custom thumbnails for Shorts are added in YouTube Studio on a computer, and availability has been rolling out gradually. See our Shorts thumbnail guide.
- Live streams and premieres: the thumbnail is set in the stream or premiere settings before it goes live.
- Mobile app: some options are easier or only available in the browser version of Studio. Try a computer.
Cause 6: a temporary glitch
If everything above looks fine, try the simple fixes:
- Refresh Studio, or open it in a private window.
- Try another browser.
- Clear the browser cache.
- Turn off extensions that touch YouTube for a minute.
- Wait an hour and try again.
What if it uploads but doesn't show?
If the file uploads and the thumbnail on the video still looks like an auto-picked frame, read why a YouTube thumbnail is not changing. If it shows but looks soft, see why it might be blurry.
A short checklist
- Phone verified, and you've signed out and back in?
- No strikes or restrictions on the channel?
- You have the right role for the channel?
- JPG or PNG, 16:9, under the size limit?
- Using the right place (Studio on a computer for Shorts)?
Frequently asked questions
Why is the custom thumbnail button greyed out?
Most often the account isn't phone-verified. Verify it, then sign out and back in.
Do I need a certain number of subscribers to use custom thumbnails?
No. YouTube's requirement is account verification and good standing, not a subscriber count.
Can I use a custom thumbnail on an old video?
Yes. You can replace a thumbnail at any time. See how to change a YouTube thumbnail and check whether it worked.
Why does YouTube reject my thumbnail?
Usually the file is the wrong format, over the size limit, or not 16:9. Check it with a size checker before you upload again.
Once your custom thumbnail is in, make it count. Here's a quick way to get a free score and fixes before you publish.
