Image Resizer

Resize any image to exact pixel dimensions or a percentage of the original, then export it as PNG, JPEG or WebP. Everything happens on a canvas inside your browser — your image never leaves your device.

image-resizer · runs locally
Drop an image here, click to browse, or paste from the clipboard. PNG, JPEG, WebP, GIF or SVG.

How this image resizer works

Drop in an image and the tool reads its natural dimensions straight into the width and height fields. Type a new width and, with the aspect-ratio lock on, the height updates automatically so nothing gets stretched — or switch to percentage mode and pick 25%, 50%, 75% or a custom scale. The image is then redrawn on a canvas at the target size and re-encoded to PNG, JPEG or WebP, all locally in your browser.

One detail sets this apart from a naive canvas resize: for large reductions (more than 2×), the tool downscales in successive halves before the final draw. Browsers use fast but simple interpolation, and shrinking a 4000px photo to 400px in one step produces visible aliasing and moiré. Stepping down in halves averages pixels more gently at each stage, so fine lines and text stay clean.

Resizing an image step by step

  1. Drop, paste or browse for an image — PNG, JPEG, WebP, GIF or SVG.
  2. Enter exact pixel dimensions, or switch to percentage mode.
  3. Pick an output format, and a quality level for JPEG or WebP.
  4. Click Resize image, check the preview and sizes, then download.

Getting the smallest possible file

Resolution is the biggest lever on file size — halving both dimensions cuts the pixel count by 75%, which usually shrinks the file far more than any quality slider. For web work, resize to roughly the pixels you will actually display (or 2× that for high-DPI screens), then squeeze the result further with the Image Compressor. If you need the image inline in HTML or CSS, the Image to Base64 Converter turns the resized file into a data URI.

Frequently asked questions

Is my image uploaded to a server?

No. The resize happens on an HTML canvas entirely inside your browser — the file is read locally, redrawn at the new size and re-encoded on your device. Nothing is transmitted, which also makes the tool fast and safe for private photos or client work.

Does resizing an image lose quality?

Downscaling discards pixels but usually looks great because detail is averaged away gracefully — this tool steps large reductions down in halves to keep edges crisp. Upscaling cannot invent detail, so enlarged images look progressively softer. Resize down whenever you can, and keep the original file.

Which output format should I choose?

PNG for screenshots, logos and anything needing transparency; JPEG for photos where small file size matters; WebP when your target supports it — it typically beats JPEG at the same visual quality. Note that exporting a transparent image to JPEG fills the background white, since JPEG has no alpha channel.

What is the largest image this can handle?

Browser canvases top out around 16,000 pixels per side (and total-area limits can be lower on mobile Safari), so the tool rejects target dimensions beyond ~16k. Very large sources may also be slow to decode on low-memory devices — but typical camera photos up to 50+ megapixels work fine.

Image Compressor

Shrink JPEG and WebP file sizes with a quality slider and live before/after comparison.

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Image Converter

Convert images between PNG, JPEG and WebP formats without uploading them anywhere.

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Image to Base64 Converter

Turn any image into a Base64 data URI with ready-to-paste HTML and CSS snippets.

Open tool →