How the Image Converter and Resizer Works

DocDox Image Converter and Resizer handles format conversion and dimension resizing for JPG, PNG, WebP, and AVIF images using the browser's built-in Canvas API — no external libraries, no server, no uploads. Every transformation happens locally in milliseconds.

For format conversion, select the target format and the tool re-encodes your image using the Canvas toBlob() API with the specified MIME type. For resizing, specify exact pixel dimensions or a percentage scale, with an option to maintain the original aspect ratio automatically. A live preview shows the approximate output dimensions before you process. You can combine both operations in a single step — for example, convert a PNG to WebP and resize it to 1200 pixels wide simultaneously.

This is particularly useful for preparing images for platforms with specific technical requirements. Social media sites, e-commerce platforms, and content management systems all have exact dimension and format requirements, and this tool handles all of them without requiring Photoshop or any desktop application.