How it works
The browser decodes your picture, draws it at the chosen pixel dimensions, and encodes a new JPEG, WebP or PNG. Output is limited to 16 megapixels and 8,192 pixels per side. Compression and color handling depend on your browser. Quality controls apply to JPEG and WebP; PNG ignores quality. A smaller output file is not guaranteed. Enlarging pixels cannot recover missing detail.
The formulaLocked aspect ratio = original width ÷ original height
Size change (%) = (output bytes ÷ original bytes − 1) × 100
Put it into practice
EXAMPLEWith the ratio locked, resizing a 2,400 × 1,600 picture to 1,200 pixels wide produces an 800-pixel height.
EXAMPLEA transparent PNG exported as JPEG gets a white background. PNG and supported WebP exports can retain transparency.
Good to know
Does my picture leave my device?
This tool does not upload your image or send image data to a server. Previews and downloads use local browser memory. Clear the image or close the page to discard it. Normal page delivery is covered by the site privacy notice.
What happens to metadata and animation?
The output is a newly encoded still image, not a copy of the original metadata container. Do not rely on preserving EXIF, GPS, print resolution or color profiles. Animated PNG/WebP, GIF, SVG, HEIC and RAW are not supported.
Why can export fail?
The browser may run out of memory, reject a damaged image or lack a requested encoder. Reduce dimensions or choose PNG/JPEG. Unsupported output formats are reported rather than silently mislabeled.