This page bulk converts ISBN10's to ISBN13's (also known as EAN's) and vice versa.
Enter your ISBN's or EAN's in whatever bulk format you like and click the "Convert ISBN's" button. CSV, space, or tab separated is supported, only ISBN's and EAN's are converted, other text is left as it was entered.
Please be aware that some EAN's (e.g. the 979... range) are outside the addressable range of ISBN (10) and will not be converted. Those EAN's will be left as-is.