Does it maintain aspect ratio automatically?

No. Width and height are set independently. If you want to maintain the aspect ratio, calculate the proportional dimension manually before entering it (e.g. if original is 1600×900 and you set width to 800, set height to 450).

What format is the output?

The output is always PNG, generated via the Canvas toDataURL API. If you need a JPG output, use the Image Compressor tool which outputs JPEG.

Is there a maximum input image size?

No hard limit, but images above ~20 megapixels may be slow to draw onto the Canvas depending on your device. Most web and social media images are well within this range.

Will resizing reduce the file size?

Reducing dimensions generally reduces file size, but PNG is lossless so the output may still be larger than a compressed JPG at the same dimensions. For smaller files, compress after resizing.

Image Resizer

Resize images to exact pixel dimensions in your browser — no upload, no server.

How to use this tool

1Drop an image onto the upload zone or click it to browse for a file.
2The original pixel dimensions are shown below the preview and pre-filled into the Width and Height fields.
3Edit the Width and/or Height values to your target dimensions.
4Click 'Download Resized' — the resized PNG is saved directly to your device.

About Image Resizer

Uploading an oversized image to a CMS, email template, or social platform wastes bandwidth and slows page loads. This Image Resizer draws your image onto an HTML Canvas at the dimensions you specify, then triggers a PNG download — all without sending the file anywhere. Drop or click-to-upload any browser-supported image format (JPG, PNG, WebP, GIF, AVIF), and the tool pre-fills the width and height fields with the original pixel dimensions so you can see exactly what you're starting from. Change either dimension to your target size and click Download Resized. The tool does not enforce aspect ratio automatically — you control both axes independently, which is useful when you need to hit an exact canvas size like 1200×630 for Open Graph images or 800×800 for product thumbnails. The output is always PNG to preserve quality through the Canvas re-encoding step.

Frequently asked questions

Related Tools

Image to Base64

Convert any image file to a Base64 data URL for embedding in HTML, CSS, or JSON.

Image

Image Compressor

Compress JPG, PNG, and WebP images client-side using the Canvas API — no uploads, no server.

Image

PNG to JPG Converter

Convert PNG images to JPG in your browser — transparency filled white, quality adjustable.

Image