Image Resizer

Resize images without uploading them.

LocalYour data is processed locally in your browser and is not uploaded to Alphzen.

Resize uses the browser’s drawImage scaler. Animated GIFs become the first frame. SVG is not rasterized. Files never leave this tab.

Choose image

FormatQuality (0.80)

WidthHeightLock aspect ratio

How to use

Choose an image.
Enter a width, a height, or both. Lock aspect ratio unless you intend to stretch.
Export JPEG, WebP, or PNG and download.

Local canvas resize. The file is not uploaded.
Aspect lock from width or height, or free stretch.
Same GIF (first frame) and SVG limits as the compressor.
Optional quality when exporting JPEG or WebP.
Honest about interpolation: this is browser default scaling, not a print-production resampler.

Fit a 1200px blog width

width 1200, lock aspect

Will upscaling look sharp?

No. Enlarging invents pixels. Use it for a rough fit, not for print.

Is the algorithm Lanczos?

It is whatever the browser’s drawImage uses. Alphzen does not ship a custom kernel.

Resizing in the browser is useful when a screenshot or export is larger than the slot it will occupy. Doing it locally avoids a third-party upload.

After you have the right pixel size, the compressor can still reduce JPEG/WebP quality if the file is heavy.