Free Thumbnail Image Resizer
Resized entirely in your browser — your image is never uploaded to our servers.
Upload any PNG, JPEG, or WebP image and resize it to the correct YouTube thumbnail dimensions (1280×720), YouTube Shorts (1080×1920), or square (1080×1080). Choose between a centred cover-crop or a letterboxed contain mode, pick a background colour, and download a clean PNG — ready for direct upload to YouTube Studio.
YouTube thumbnail dimensions explained
YouTube recommends thumbnails at 1280×720 pixels with a 16:9 aspect ratio and a maximum file size of 2MB. The format should be PNG or JPEG — PNG is preferred for images with text or flat colour blocks because it is lossless. Thumbnails that do not match 16:9 are letterboxed or pillarboxed by YouTube, which can leave black bars that look unfinished.
If you are designing a YouTube Shorts thumbnail — or creating a vertical version of the same thumbnail for TikTok or Instagram Reels — the correct size is 1080×1920 (9:16). Square thumbnails at 1080×1080 are used for community posts and some social media shares. This tool handles all three with a single upload.
A common mistake is uploading a thumbnail that is technically the right pixel dimensions but has critical content near the edges. YouTube overlays play buttons, duration badges, and channel avatars in the bottom-left and bottom-right corners. Design your thumbnail with a safe-zone margin of at least 5–8% from each edge to avoid these overlays obscuring important text or the subject's face.
How to use the thumbnail resizer
- Upload your PNG, JPEG, or WebP image by clicking the upload zone or dragging a file onto it.
- Select your target Output size from the preset menu.
- Choose Cover (crops to fill — good for photos) or Contain (letterboxes — good when you do not want to crop anything).
- If you chose Contain, pick a Background colour using the colour picker.
- Click the resize button, then Download PNG to save the result.
FAQ
Is my image uploaded to a server?
No. The resize happens entirely in your browser using the HTML Canvas API. Your image is never sent over the network.
What is the difference between Cover and Contain?
Cover (the default) scales your image until it fills the target size entirely, then crops the overflow from the centre. Contain scales your image until it fits entirely within the target size, then fills the remaining space with your chosen background colour — also known as "letterboxing" or "pillarboxing".
What format does the output use?
The download is always a PNG file. YouTube accepts JPG, PNG, and GIF for thumbnail uploads — PNG is a good default because it is lossless and preserves sharp edges on text and flat-colour areas.
What are the available output sizes?
YouTube Thumbnail (1280×720, 16:9) — the standard YouTube upload size. YouTube Shorts / TikTok (1080×1920, 9:16). Square (1080×1080) — useful for Instagram and community posts.
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