ConvertImage is free and will watermark your logo directly online.
To protect your images or insert the logo of your brand, add this page to your favorites! Do not look how to add a watermark to your photo without any software: ConvertImage inserts an image or a logo over your initial photo by blending it, at the location, the size and the transparency of your choice.
Watermarking (also known as "Picture-In-Picture") prevents any other users (for instance competitors) to easily re-use your image without your permission. ConvertImage also allows you to insert a text watermark over your image!
ConvertImage is your online file conversion tool :