Resize a local image with an aspect-ratio lock and download JPEG, PNG or WebP.
n Inputs are processed locally by this tool. Other site plugins, hosting logs, ads and embeds have their own data handling. Text limit: 1 MiB UTF-8.
How to use Image Resizer & Converter
- Choose an image.
- Enter dimensions and decide whether to keep the original ratio.
- Select the format, review the preview and download.
Example
A 1600 × 900 image resized to width 1200 with the lock on becomes 1200 × 675.
Method and formula
With ratio lock enabled, width determines height by original height / original width × requested width, rounded to a whole pixel. Turning the lock off uses both supplied dimensions and can stretch the image. Canvas draws the resized pixels locally.
Limits and supported input
JPEG, PNG and WebP only, up to 15 MiB and 24 million source/output pixels, with each output side at most 8,000 pixels. GIF, SVG, APNG and animated WebP are rejected. Browser format support varies. Canvas re-encoding can remove metadata and change colour handling; keep the original. Upscaling does not recover missing detail.
Privacy
This tool processes the input in your current browser tab. It does not upload your input or call a paid or remote API. Copying places text on your system clipboard; downloading saves a file on your device. Site hosting logs, analytics, ads, third-party embeds and other installed plugins are separate and can have their own data handling. JavaScript is required for the tool, while this explanation remains available without it.
Frequently asked questions
What happens to the height field with the lock on?
Height is calculated from the width and original ratio.
Does a larger image gain detail?
No. Upscaling only interpolates the existing pixels.