How to prepare portfolio thumbnails for sharing

A portfolio page can look uneven when thumbnails have different shapes, sizes, or file formats. A crop that works in a folder may also cut off the subject when the site displays it in a small card.

Check the portfolio platform’s image requirements first, then prepare copies of your images for upload. TooLab’s Image Converter can convert a batch of files in your browser. It does not replace checking the crop and dimensions your portfolio needs.

Prepare the thumbnails

1. Check the portfolio site’s recommended thumbnail dimensions, aspect ratio, accepted formats, and file size limit. Open the Image Converter and keep the original files untouched so you can start over if needed.
2. Choose the images you want to share. If the site uses a fixed crop, decide which part of each image needs to remain visible in that shape. Make a separate crop or resized copy before conversion if necessary.
3. Select a file format that the portfolio platform accepts. JPG is a practical choice for photographs. PNG is useful for artwork with sharp edges or transparent areas. WEBP can be a smaller option when the site supports it.
4. Convert the selected images to the chosen format. For a portfolio with many entries, converting a batch together can help keep the file types consistent. Use clear filenames that identify the project, such as ceramic-vase-front.jpg.
5. Review the converted files before uploading. Check that each opens, has the expected proportions, and still shows the important part of the work. Upload a sample to the portfolio page and look at it at the size visitors will see.

Keep a separate folder for originals and another for sharing copies. That makes it easier to change a crop or format later without degrading or losing your source image.

Choose a format and shape

Use the site’s requested aspect ratio

An aspect ratio is the relationship between an image’s width and height. A square thumbnail has equal sides, while a wide thumbnail is broader than it is tall. Follow the platform’s stated ratio rather than forcing every image into a square. If the site crops images automatically, check its preview and reposition the crop so the subject, artwork, or key detail remains visible.

Choose JPG for photographs

JPG works on most portfolio platforms and usually suits photographs with many colors and smooth shading. It uses lossy compression, which means some image detail is discarded to reduce file size. Keep a high-quality original and inspect the sharing copy for blocky edges, smudged texture, or color changes, especially around fine detail.

Choose PNG for transparency or crisp graphics

PNG keeps transparent areas and handles sharp lines well, so it can suit illustrations, logos, and interface designs. It can create larger files than JPG for a photograph. JPG does not support transparency, so transparent parts of an image may appear filled with a background color if you convert it to JPG.

Use WEBP only if the destination accepts it

WEBP can keep good visual quality in a smaller file, but the portfolio site, content management system, or client may not accept it. If the upload fails or the preview is blank, make another copy in a format the site lists, usually JPG or PNG.

Match the needed pixel dimensions

Pixel dimensions describe an image’s width and height in pixels. A format conversion alone does not guarantee that the image has the dimensions or crop the platform recommends. If a thumbnail looks soft, check the source dimensions and prepare a properly sized copy from the original. Enlarging a small image cannot restore detail that was not there.

Fix common thumbnail problems

1. The upload is rejected. Check the accepted formats and file size limit on the portfolio site. Convert the image to one of its supported formats, then try one file first to confirm the result.
2. The subject is cut off. The site may be using a fixed crop. Create a version with the subject positioned inside the visible area, or adjust the crop in the site’s preview if that option is available. Do not stretch the image to fill the box, because that distorts its proportions.
3. The thumbnail looks blurry. Start with a larger original image and check its pixel dimensions before preparing the copy. Avoid enlarging a small image just to meet a recommended size, since that can make it look softer without adding detail.
4. The file is still too large. Check whether the image is much larger in pixels than the site needs. Make a correctly sized copy with an image editor or the portfolio site’s own editing tools, then convert it. The Image Converter changes formats, so do not assume conversion by itself will reduce the image to the required dimensions.
5. Transparent areas look wrong. Use PNG or another format that supports transparency if the platform accepts it. If you must use JPG, place the image on the intended background before saving a sharing copy.
6. Colors look different after conversion. Compare the converted file with the original in the same viewer and check the portfolio’s preview. Some formats and display pipelines can change how colors appear. If color accuracy matters, keep the original and use a format the platform recommends.

Make the portfolio easy to browse

Use a consistent visual approach across the set. Keep the subject a similar size in each thumbnail, use a repeatable crop where it makes sense, and avoid mixing very dark images with very bright ones without checking how the row looks together. A consistent set helps visitors scan projects without making every thumbnail look identical.

Use descriptive filenames before uploading. Names such as ceramic-vase-detail.jpg are easier to identify than IMG_4821.jpg, especially when you prepare several versions. Keep the file extension matched to the actual format after conversion.

The Image Converter runs in your browser, and files you open stay on your device. Check the final uploaded preview before sharing the portfolio link.