Image Spec Check

YouTube tool

YouTube Thumbnail Checker

Check whether a custom thumbnail meets YouTube's recommended dimensions, 16:9 aspect ratio, accepted formats, and device-specific file size limits.

Quick answer

YouTube thumbnail specs at a glance

YouTube recommends custom video thumbnails at 3840 x 2160 px in a 16:9 ratio, with a minimum width of 640 px. JPG, GIF, and PNG are accepted. The stated file limit is 2MB for uploads from mobile devices and 50MB from desktop, so a file above 2MB may require desktop upload.

Website image size checker
Recommended size
3840 x 2160 px
Minimum size
640 px wide
Aspect ratio
16:9
File types
JPG, GIF, PNG
File size
2MB mobile, 50MB desktop
Common issue
Wrong ratio or mobile upload file too large

Direct answer

What are the YouTube thumbnail requirements?

YouTube recommends custom video thumbnails at 3840 x 2160 px in a 16:9 ratio, with a minimum width of 640 px. JPG, GIF, and PNG are accepted. The stated file limit is 2MB for uploads from mobile devices and 50MB from desktop, so a file above 2MB may require desktop upload.

Last verified:

RequirementCurrent guidanceStatus and source
Recommended dimensions3840 x 2160 px; minimum width 640 pxYouTube states both the recommended resolution and minimum width.OfficialYouTube Help: Add video thumbnails
Aspect ratio16:9YouTube recommends 16:9 because it is the most common player and preview ratio.OfficialYouTube Help: Add video thumbnails
Accepted formatsJPG, GIF, PNGThese formats are listed in YouTube's custom thumbnail guidance.OfficialYouTube Help: Add video thumbnails
Maximum file size2MB mobile; 50MB desktopThe upload ceiling depends on whether the thumbnail is uploaded from mobile or desktop.OfficialYouTube Help: Add video thumbnails
Last verified
Platform target3840 x 2160 px
Recommended formatJPEG
File limit50MB
Supported formatsJPEG, PNG, GIF

Compliance

Compliance results

Upload an image to see dimension, aspect ratio, format, and file size checks.

  • ResolutionWaiting for uploadRecommended 3840 x 2160 px with a minimum width of 640 px.
    Registry value: 3840 x 2160 px; minimum width 640 px
    Waiting for an uploaded image.    Official source
  • Aspect ratioWaiting for uploadRecommended 16:9.
    Registry value: 16:9
    Waiting for an uploaded image.    Official source
  • FormatWaiting for uploadJPG, GIF, or PNG.
    Registry value: JPG, GIF, PNG
    Waiting for an uploaded image.    Official source
  • File sizeWaiting for uploadMaximum 2MB on mobile or 50MB on desktop.
    Registry value: 2MB mobile; 50MB desktop
    Waiting for an uploaded image.    Official source

Preview

YouTube player and recommendation preview

12:48

Export

Crop, compress, and export

Good quality range for product images.
Spec sources

Measurable checks

What does this YouTube thumbnail checker test?

It measures the uploaded image against the YouTube registry values for pixel dimensions, aspect ratio, file format, file size, and other metadata-based rules. Each result includes the measured value, expected guidance, and source status.

  • Dimensions
  • Aspect ratio
  • File type
  • File size

Policy limits

What can the checker not verify automatically?

Visual policies such as backgrounds, text, watermarks, borders, product fill, subject placement, and crop quality still need manual review. These items are never reported as automatically passed.

Corrective action

How do I fix a failed YouTube image?

If the image fails, resize or crop it to the target frame, export one of the accepted formats (JPEG, PNG, GIF), and keep the file within 50MB before uploading.

Privacy

Are uploaded images stored?

No. The original image is used only for the current browser check and export request. It is not published, assigned a public URL, or persisted after processing.

More tools

Other marketplace image checkers

Compare the current file against another marketplace before exporting a final product photo.

Etsy Listing Photo Size CheckerAmazon Main Image Size CheckerHow requirements are verifiedImage Spec Check home

Verification

Sources and update history

Last verified:

How the labels work

Official means the value is explicitly stated in a primary marketplace source. Recommended is a safer working or export target. Manual review identifies visual or policy checks that file metadata cannot confirm.

Update note

Marketplace requirements can change by region, category, account, or upload surface. Confirm unusual cases in the linked platform documentation. Passing this checker does not guarantee marketplace approval.

Read the source and verification methodology.

Common questions

Frequently asked questions

  • What is the best YouTube thumbnail size?
    YouTube recommends 3840 x 2160 px custom thumbnails with a minimum width of 640 px and a 16:9 aspect ratio.
  • Can I upload a PNG YouTube thumbnail?
    Yes. YouTube supports JPG, GIF, and PNG. JPEG is often the most efficient choice for photo-based thumbnails.
  • Why does a YouTube thumbnail need a 16:9 ratio?
    Most YouTube surfaces display video thumbnails in a 16:9 frame, so matching that ratio reduces unexpected cropping.
  • Will this tool upload my YouTube thumbnail?
    No. Your thumbnail is used only for the current check and export. The original upload is not saved.
  • Which export format should I use for a YouTube thumbnail?
    JPEG is usually the best choice for photo-based thumbnails because it keeps file size low while preserving visual quality.

Export guidance

JPEG is usually best for photographic product images. PNG is useful for transparent or graphic assets. WebP can be efficient for storefront performance, but use JPEG or PNG when the target marketplace does not accept WebP.