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YouTube Thumbnail Size Checker & Compressor

Check thumbnail dimensions and file size, then export an exact 1280 × 720 JPG, WebP or PNG locally.

Free browser toolRuns in your browserNo sign-up

Export review

Choose a source thumbnail

The source is never uploaded. Exports are rasterized to 1280 × 720; cover mode crops edges while contain mode preserves the whole image.

No thumbnail selected

About the YouTube Thumbnail Size Checker & Compressor

YouTube Thumbnail Size Checker & Compressor reads a local image's pixel dimensions, aspect ratio and file size before creating an exact 1280 × 720 export. Cover mode fills the canvas by cropping edges, while contain mode preserves the whole source and adds configurable bars.

JPG and WebP exports use a bounded quality search to move toward the entered maximum size without dropping below the tool's minimum quality guard. PNG remains lossless, so a requested size cannot be guaranteed.

The resulting size is always reported before download. Image decoding, resizing, encoding and export run in the browser; the selected file is not sent to a server.

Key features

  • Source dimensions, ratio and byte-size report
  • Exact 1280 × 720 output canvas
  • Cover crop or contained-image framing
  • Configurable bars for contained images
  • JPG, WebP and lossless PNG export
  • Target-size quality search for JPG and WebP
  • Actual output-size reporting
  • Local processing and download

How to use

  1. 1Choose a JPG, PNG or WebP thumbnail up to 20 MB.
  2. 2Review its source dimensions and whether the aspect ratio already matches 16:9.
  3. 3Select cover to fill the canvas or contain to preserve the full source.
  4. 4Choose an output format, starting quality and target size, then create and inspect the optimized result.

Examples

Prepare an oversized thumbnail
Input: 4000 × 2250 PNG, JPG output and 1,900 KB target
Output: A 1280 × 720 JPG with its actual encoded size displayed

Inspect small text and fine edges after compression before uploading.

Frequently asked questions

Will the export always be 1280 × 720?
Yes. Both framing modes produce a 1280 × 720 raster image.
Can the tool guarantee a target file size?
Not always. JPG and WebP move toward the target within a quality guard. PNG is lossless and ignores quality settings.
What is the difference between cover and contain?
Cover fills 16:9 and can crop source edges. Contain keeps the full image and fills unused space with the chosen colour.
Is my thumbnail stored online?
No. The source and generated output remain in the current browser session unless you download the file.

Continue your workflow

Open a related tool to prepare your files or refine the finished result.