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Image Resizer

Resize images to exact dimensions or by percentage, with optional aspect-ratio lock. Runs entirely in your browser — images never leave your device.

Runs in your browser — files never leave your device

How it works

Choose an image and it is decoded locally, with its original pixel dimensions shown right away. Type a target width or height, click Resize & download, and the tool redraws the image at the new size on an off-screen canvas in your browser, then saves the result as a PNG. Any format your browser can display works as input — JPG, PNG, WebP, GIF, BMP — and the output is always PNG.

The aspect-ratio lock is on by default and does the arithmetic for you: it keeps the original proportions by computing the dimension you did not type. A 4,000 × 3,000 photo set to 1,200 wide becomes 1,200 × 900; a 1,920 × 1,080 frame set to 720 high becomes 1,280 × 720. Values are rounded to whole pixels, so a 3,024 × 4,032 portrait shot at 1,000 wide comes out exactly 1,000 × 1,333. Uncheck the lock and both fields become free — useful when a form demands exact dimensions, with the caveat that a changed ratio stretches the picture.

Downscaling is where resizing shines: shrinking a camera photo for a web page, an email attachment, an avatar, or an upload form with a pixel limit. Enlarging works too, but the browser can only interpolate between existing pixels — an upscaled image gets softer, not more detailed, so start from the largest original you have.

Two side effects are worth knowing. First, PNG output is lossless and keeps transparency, but it stores photographs less compactly than JPG — a resized photo can occupy more bytes than the original despite having fewer pixels, so pair this tool with an image compressor when file size matters. Second, redrawing on a canvas drops EXIF metadata such as GPS location, while the orientation flag is honored during decoding, so portrait photos stay upright. Everything happens on your device; the image never leaves your browser.

Frequently asked questions

Which formats can I resize, and what do I get back?
You can load any image your browser can decode — JPG, PNG, WebP, GIF, BMP, and more. The output is always a PNG, regardless of input format, saved as resized-<name>.png. PNG was chosen because it is lossless and keeps transparency.
How does the aspect-ratio lock work?
The tool divides the original width by the original height and uses that ratio to fill in the field you did not type. Set a 1,920 × 1,080 image to 720 high and the width becomes 1,280 automatically. Results are rounded to whole pixels, so a 3,024 × 4,032 photo resized to 1,000 wide comes out 1,000 × 1,333.
Can I make an image larger than the original?
Yes — enter dimensions bigger than the source and the canvas scales it up. Upscaling interpolates between existing pixels, so it cannot add detail; enlarged images look progressively softer. The tool is at its best shrinking large photos down for the web, email, or upload size limits.
Why is the resized file bigger in megabytes than my original?
Because the output is lossless PNG. A JPG photo stores pixels far more compactly than PNG can, so even at smaller dimensions the PNG may weigh more in bytes. If file size matters, run the resized PNG through an image compressor, or keep photos in JPG end to end.
Is transparency preserved?
Yes. PNG output keeps the alpha channel, so a transparent logo or sticker stays transparent after resizing. JPG sources have no transparency to begin with, so they come out on the same opaque background they went in with.
What happens to EXIF data and photo orientation?
Redrawing on a canvas strips EXIF metadata — camera model, capture date, GPS location — from the output. Modern browsers apply the EXIF orientation flag while decoding, so the dimensions you see already match the upright photo and the result is not sideways.
Are my images uploaded anywhere?
No. The image is decoded, redrawn, and re-encoded on an in-memory canvas in your own browser. Nothing is transmitted to a server, which makes the tool safe for private photos, documents, and unpublished work.

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