Online Photo Thumbnail Maker
Other than using a desktop application, you can use an online photo thumbnail maker. This should be a handy alternative when you are in a situation where you cannot open your regular photo application to make thumbnails of your photos but have a relatively fast internet connection instead. If you’re looking for a fast online tool you can use to resize your photos to thumbnail size, go ahead to Quick Thumbnail.
You can upload a photo either from your computer or from an URL. The image formats supported include gif, jpeg, jpg, and png. Make sure that the size of the photo uploaded doesn’t exceed 2048 KB (2 MB).
The uploaded photo can be resized based on percentage, fixed size, or standard size. You can also apply some filters like greyscale, sepia, negative, emboss, blur, sketch or edge effect to the photo. Once all the settings are done, click the “resize it” button to start the photo thumbnail creation.
Note that you can have several sizes for a photo. Just use every size you want the photo to be resized into and you will get several photos in different sizes.