Look at the actual layout where an image appears. A card thumbnail, article illustration and wide hero image have different requirements. Choose dimensions that suit the available width and account for higher-density screens where appropriate. Uploading a very large source for every small card can create unnecessary page weight.
Use the U18-CHAN Image Resizer alongside this guide.
Resize without accidental distortion
Open Image Resizer and choose a source image. Keep the aspect ratio locked when you want proportions preserved, then enter the intended width or height. The paired dimension updates automatically. If you need a different shape, crop deliberately rather than forcing an image into mismatched proportions.
Choose a sensible format
JPEG suits many photographic images that do not need transparency. PNG can suit graphics where lossless output is useful. WebP offers another browser-supported option for still images. Test the file in the browsers and publishing system used by your audience rather than choosing a format solely because its name is familiar.
Inspect quality and file size together
A small file is useful only if it still communicates what the reader needs. Use Image Compressor for a JPEG or WebP export, then compare small text, fine detail and gradients. The result can be larger than the original, so check the reported size. Keep an original copy and avoid repeated lossy exports.
Publish with clear context
Give an informative image a meaningful description in your publishing system, use responsive image sizes and check its layout on a phone. Conversion tools do not write your page’s alternative text or configure its caching. Review dimensions, transparency and appearance in the final page, and use specialist software for animated files or print colour workflows.
A simple finishing check
Keep the original input, inspect the result and confirm that it fits the destination where you plan to use it. If a result looks unexpected, try a small harmless example and read the limitations on the tool page before proceeding.
Browse all free U18-CHAN tools to continue, or report a problem with a clear description of the tool and browser.