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Tools Harbor

Image Resizer

Resize images to specific dimensions or scale by percentage.

Mode

Resize images precisely, in your browser

Whether you need a 1024px profile photo, a 300×250 ad banner, or a 50% thumbnail, this resizer handles it locally in your browser — no upload, no account, no watermark.

Two modes

  • Exact pixels — set a target width and/or height in pixels. With “Keep aspect ratio” on, you can leave one blank and the other is computed automatically.
  • Percentage — scale the image to 10%–200% of its current size. Useful for quick downscaling without measuring.

Common image sizes to target

UseCommon dimensions
Twitter header1500 × 500
Open Graph image1200 × 630
Instagram square1080 × 1080
YouTube thumbnail1280 × 720
Favicon32 × 32
iOS app icon1024 × 1024

How the resampling works

The tool draws the source image onto an HTML5 canvas at the target size with high-quality image smoothing enabled. The browser’s native resampler is used — it produces results indistinguishable from a local image editor for typical downscales.

Privacy

All reads, resizes and downloads happen in your browser. No image data leaves your device.

Frequently asked questions

Does resizing reduce quality?
Downscaling (making smaller) loses detail but typically looks fine at the new size. Upscaling (making larger) has nothing to work with — it invents pixels that were not there, producing blurry or pixelated output. For better upscaling, use an AI tool instead.
What happens if I disable "Keep aspect ratio"?
The image is stretched to fit exactly the width and height you specify. This produces distorted output unless you are intentionally compressing a known-aspect image into a container that matches.
Why does the file size go down more than expected?
Smaller pixel dimensions compress better on disk. A 50% width reduction often cuts file size by 70%+ because JPEG and WebP exploit spatial similarity, which grows at larger sizes.