Grammarly is a useful add-on for Firefox, which is addressed to people who publish various types of texts on the Internet in English. The extension adds spell-checking and grammar functions to the browser to prevent accidental errors. Grammarly is good at detecting words used in the wrong context, as well as various types of typos, lack of punctuation marks or other grammatical errors.

Any errors in the texts being edited are recorded in real time by highlighting, together with information on proposed amendments. The plugin can be successfully used e.g. when creating e-mail messages in Gmail or publishing content on Facebook, Twitter, Linkedin, Tumblr and any other text form available on almost any website.

After registering a user account, weekly reports with statistics will be sent to the e-mail inbox. The paid version of Grammarly is equipped with additional error detection, vocabulary enhancement suggestions or plagiarism detection.