How do I stop my image from stretching?

Keep the Maintain Aspect Ratio toggle on so width and height scale together proportionally.

Can I resize to a custom size?

Yes, enter any width and height you need for the output.

Does resizing upload my image?

No. It's processed locally in your browser with canvas.

Can I make a thumbnail larger?

You can upscale, but it won't add detail. Start from the highest-resolution source for best results.

What formats can I export?

Standard image formats like PNG and JPG are supported on export.

Will it keep my image quality?

Downscaling stays sharp; upscaling is limited by the source. PNG export avoids extra compression.

Does it work on mobile?

Yes, the resizer is mobile-first and works in any browser.

Can I load a thumbnail from a video link?

Yes, paste a YouTube URL and the tool fetches the thumbnail to resize.

Yes, free with no watermark and no limits.

Thumbnail Tools

Thumbnail Resizer

Resize any thumbnail to YouTube's recommended 1280×720, full HD 1920×1080, 640×480 or a custom size — with optional aspect-ratio lock so nothing stretches. Runs entirely in your browser.

Upload your own image

Quick answers

Straight to the point

What size should a YouTube thumbnail be?

YouTube recommends 1280×720 pixels (16:9) with a minimum width of 640px, under 2MB, as JPG, PNG, GIF or BMP. This resizer outputs exactly 1280×720 by default, and also offers 1920×1080, 640×480 and custom dimensions with aspect-ratio lock to avoid stretching.

How do I resize a thumbnail without stretching it?

Enable the Maintain Aspect Ratio toggle. When on, changing the width auto-adjusts the height (and vice versa) so the image scales proportionally and never distorts. Turn it off only when you deliberately need exact non-proportional dimensions.

Why this tool

What makes the Thumbnail Resizer useful

Uploading the right dimensions keeps thumbnails crisp and within YouTube's size limits. The resizer makes that one click, privately and for free.

Common presets

1280×720, 1920×1080 and 640×480 ready in one tap.

Custom dimensions

Type any width and height for the output you need.

Aspect-ratio lock

Keep proportions automatically so images never distort.

Local & free

Resizing runs on your device — no uploads, no signup.

Step by step

How to use the Thumbnail Resizer

Load an image, choose a preset or type custom dimensions, and the tool redraws it on a canvas at the new size. With aspect lock on, it keeps proportions; export the result as an image file.

1
Load an image
Paste a thumbnail URL or upload a file.
2
Pick dimensions
Choose a preset or enter custom width and height.
3
Lock the ratio
Keep Maintain Aspect Ratio on to avoid stretching.
4
Export
Download the resized image.

What is the Thumbnail Resizer?

The Thumbnail Resizer scales images to YouTube-ready dimensions in your browser, with presets for the most-used sizes and an aspect-ratio lock.

Who should use it?

Creators preparing thumbnails for upload, designers standardising image sizes, and anyone who needs a quick resize without installing software.

Common use cases

Preparing a thumbnail at YouTube's recommended 1280×720
Making a 1080p version for large displays
Standardising image sizes across a content library
Shrinking an oversized image under the 2MB upload limit

Pro tips

• Start from the highest-resolution source for the cleanest resize.
• 1280×720 is the safe default for uploads; 1920×1080 suits large displays.

Mistakes to avoid

• Disabling aspect lock and accidentally stretching faces and text.
• Upscaling a tiny image and expecting it to gain detail — it can't.

Alternatives & related approaches

To change shape rather than size, use the Cropper. To fetch a source thumbnail first, use the Downloader.

FAQ

Frequently asked questions

1280×720 pixels at 16:9, under 2MB. This tool outputs that by default and supports other sizes too.

Keep going

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Thumbnail Cropper

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