The "Collins German to English Dictionary" is available to use for free on the Collins website. Alternatively, the "Langenscheit Standard Dictionary," "Merriam-Webster's German-English Dictionary" and "Webster's New World German Dictionary" have all received positive customer reviews on Amazon, as of 2015.
The Collins online dictionary features a simple search tool and can switch between German to English and English to German translation. An extra option above the search box allows the user to enter German characters such as vowels that have an umlaut.
The "Langenscheit Standard Dictionary" includes 130,000 references and includes idiomatic expressions. "Mirriam-Webster's German-English Dictionary" includes words and phrases in American English. "Webster's New World German Dictionary" also includes over 100,000 translations, including current terms and explanations of how to use the terms in everyday speech.